PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1239887)

Clipboard (0)
None

Related Articles

1.  Risk Stratification by Self-Measured Home Blood Pressure across Categories of Conventional Blood Pressure: A Participant-Level Meta-Analysis 
PLoS Medicine  2014;11(1):e1001591.
Jan Staessen and colleagues compare the risk of cardiovascular, cardiac, or cerebrovascular events in patients with elevated office blood pressure vs. self-measured home blood pressure.
Please see later in the article for the Editors' Summary
Background
The Global Burden of Diseases Study 2010 reported that hypertension is worldwide the leading risk factor for cardiovascular disease, causing 9.4 million deaths annually. We examined to what extent self-measurement of home blood pressure (HBP) refines risk stratification across increasing categories of conventional blood pressure (CBP).
Methods and Findings
This meta-analysis included 5,008 individuals randomly recruited from five populations (56.6% women; mean age, 57.1 y). All were not treated with antihypertensive drugs. In multivariable analyses, hazard ratios (HRs) associated with 10-mm Hg increases in systolic HBP were computed across CBP categories, using the following systolic/diastolic CBP thresholds (in mm Hg): optimal, <120/<80; normal, 120–129/80–84; high-normal, 130–139/85–89; mild hypertension, 140–159/90–99; and severe hypertension, ≥160/≥100.
Over 8.3 y, 522 participants died, and 414, 225, and 194 had cardiovascular, cardiac, and cerebrovascular events, respectively. In participants with optimal or normal CBP, HRs for a composite cardiovascular end point associated with a 10-mm Hg higher systolic HBP were 1.28 (1.01–1.62) and 1.22 (1.00–1.49), respectively. At high-normal CBP and in mild hypertension, the HRs were 1.24 (1.03–1.49) and 1.20 (1.06–1.37), respectively, for all cardiovascular events and 1.33 (1.07–1.65) and 1.30 (1.09–1.56), respectively, for stroke. In severe hypertension, the HRs were not significant (p≥0.20). Among people with optimal, normal, and high-normal CBP, 67 (5.0%), 187 (18.4%), and 315 (30.3%), respectively, had masked hypertension (HBP≥130 mm Hg systolic or ≥85 mm Hg diastolic). Compared to true optimal CBP, masked hypertension was associated with a 2.3-fold (1.5–3.5) higher cardiovascular risk. A limitation was few data from low- and middle-income countries.
Conclusions
HBP substantially refines risk stratification at CBP levels assumed to carry no or only mildly increased risk, in particular in the presence of masked hypertension. Randomized trials could help determine the best use of CBP vs. HBP in guiding BP management. Our study identified a novel indication for HBP, which, in view of its low cost and the increased availability of electronic communication, might be globally applicable, even in remote areas or in low-resource settings.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Globally, hypertension (high blood pressure) is the leading risk factor for cardiovascular disease and is responsible for 9.4 million deaths annually from heart attacks, stroke, and other cardiovascular diseases. Hypertension, which rarely has any symptoms, is diagnosed by measuring blood pressure, the force that blood circulating in the body exerts on the inside of large blood vessels. Blood pressure is highest when the heart is pumping out blood (systolic blood pressure) and lowest when the heart is refilling (diastolic blood pressure). European guidelines define optimal blood pressure as a systolic blood pressure of less than 120 millimeters of mercury (mm Hg) and a diastolic blood pressure of less than 80 mm Hg (a blood pressure of less than 120/80 mm Hg). Normal blood pressure, high-normal blood pressure, and mild hypertension are defined as blood pressures in the ranges 120–129/80–84 mm Hg, 130–139/85–89 mm Hg, and 140–159/90–99 mm Hg, respectively. A blood pressure of more than 160 mm Hg systolic or 100 mm Hg diastolic indicates severe hypertension. Many factors affect blood pressure; overweight people and individuals who eat salty or fatty food are at high risk of developing hypertension. Lifestyle changes and/or antihypertensive drugs can be used to control hypertension.
Why Was This Study Done?
The current guidelines for the diagnosis and management of hypertension recommend risk stratification based on conventionally measured blood pressure (CBP, the average of two consecutive measurements made at a clinic). However, self-measured home blood pressure (HBP) more accurately predicts outcomes because multiple HBP readings are taken and because HBP measurement avoids the “white-coat effect”—some individuals have a raised blood pressure in a clinical setting but not at home. Could risk stratification across increasing categories of CBP be refined through the use of self-measured HBP, particularly at CBP levels assumed to be associated with no or only mildly increased risk? Here, the researchers undertake a participant-level meta-analysis (a study that uses statistical approaches to pool results from individual participants in several independent studies) to answer this question.
What Did the Researchers Do and Find?
The researchers included 5,008 individuals recruited from five populations and enrolled in the International Database of Home Blood Pressure in Relation to Cardiovascular Outcome (IDHOCO) in their meta-analysis. CBP readings were available for all the participants, who measured their HBP using an oscillometric device (an electronic device for measuring blood pressure). The researchers used information on fatal and nonfatal cardiovascular, cardiac, and cerebrovascular (stroke) events to calculate the hazard ratios (HRs, indicators of increased risk) associated with a 10-mm Hg increase in systolic HBP across standard CBP categories. In participants with optimal CBP, an increase in systolic HBP of 10-mm Hg increased the risk of any cardiovascular event by nearly 30% (an HR of 1.28). Similar HRs were associated with a 10-mm Hg increase in systolic HBP for all cardiovascular events among people with normal and high-normal CBP and with mild hypertension, but for people with severe hypertension, systolic HBP did not significantly add to the prediction of any end point. Among people with optimal, normal, and high-normal CBP, 5%, 18.4%, and 30.4%, respectively, had a HBP of 130/85 or higher (“masked hypertension,” a higher blood pressure in daily life than in a clinical setting). Finally, compared to individuals with optimal CBP without masked hypertension, individuals with masked hypertension had more than double the risk of cardiovascular disease.
What Do These Findings Mean?
These findings indicate that HBP measurements, particularly in individuals with masked hypertension, refine risk stratification at CBP levels assumed to be associated with no or mildly elevated risk of cardiovascular disease. That is, HBP measurements can improve the prediction of cardiovascular complications or death among individuals with optimal, normal, and high-normal CBP but not among individuals with severe hypertension. Clinical trials are needed to test whether the identification and treatment of masked hypertension leads to a reduction of cardiovascular complications and is cost-effective compared to the current standard of care, which does not include HBP measurements and does not treat people with normal or high-normal CBP. Until then, these findings provide support for including HBP monitoring in primary prevention strategies for cardiovascular disease among individuals at risk for masked hypertension (for example, people with diabetes), and for carrying out HBP monitoring in people with a normal CBP but unexplained signs of hypertensive target organ damage.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001591.
This study is further discussed in a PLOS Medicine Perspective by Mark Caulfield
The US National Heart, Lung, and Blood Institute has patient information about high blood pressure (in English and Spanish) and a guide to lowering high blood pressure that includes personal stories
The American Heart Association provides information on high blood pressure and on cardiovascular diseases (in several languages); it also provides personal stories about dealing with high blood pressure
The UK National Health Service Choices website provides detailed information for patients about hypertension (including a personal story) and about cardiovascular disease
The World Health Organization provides information on cardiovascular disease and controlling blood pressure; its A Global Brief on Hypertension was published on World Health Day 2013
The UK charity Blood Pressure UK provides information about white-coat hypertension and about home blood pressure monitoring
MedlinePlus provides links to further information about high blood pressure, heart disease, and stroke (in English and Spanish)
doi:10.1371/journal.pmed.1001591
PMCID: PMC3897370  PMID: 24465187
2.  The Influence of Health Systems on Hypertension Awareness, Treatment, and Control: A Systematic Literature Review 
PLoS Medicine  2013;10(7):e1001490.
Will Maimaris and colleagues systematically review the evidence that national or regional health systems, including place of care and medication co-pays, influence hypertension awareness, treatment, and control.
Please see later in the article for the Editors' Summary
Background
Hypertension (HT) affects an estimated one billion people worldwide, nearly three-quarters of whom live in low- or middle-income countries (LMICs). In both developed and developing countries, only a minority of individuals with HT are adequately treated. The reasons are many but, as with other chronic diseases, they include weaknesses in health systems. We conducted a systematic review of the influence of national or regional health systems on HT awareness, treatment, and control.
Methods and Findings
Eligible studies were those that analyzed the impact of health systems arrangements at the regional or national level on HT awareness, treatment, control, or antihypertensive medication adherence. The following databases were searched on 13th May 2013: Medline, Embase, Global Health, LILACS, Africa-Wide Information, IMSEAR, IMEMR, and WPRIM. There were no date or language restrictions. Two authors independently assessed papers for inclusion, extracted data, and assessed risk of bias. A narrative synthesis of the findings was conducted. Meta-analysis was not conducted due to substantial methodological heterogeneity in included studies. 53 studies were included, 11 of which were carried out in LMICs. Most studies evaluated health system financing and only four evaluated the effect of either human, physical, social, or intellectual resources on HT outcomes. Reduced medication co-payments were associated with improved HT control and treatment adherence, mainly evaluated in US settings. On balance, health insurance coverage was associated with improved outcomes of HT care in US settings. Having a routine place of care or physician was associated with improved HT care.
Conclusions
This review supports the minimization of medication co-payments in health insurance plans, and although studies were largely conducted in the US, the principle is likely to apply more generally. Studies that identify and analyze complexities and links between health systems arrangements and their effects on HT management are required, particularly in LMICs.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In 2008, one billion people, three-quarters of whom were living in low- and middle-income countries, had high blood pressure (hypertension). Worldwide, hypertension, which rarely has any symptoms, leads to about 7.5 million deaths annually from heart attacks, stroke, other cardiovascular diseases, and kidney disease. Hypertension, selected by the World Health Organization as the theme for World Health Day 2013, is diagnosed by measuring blood pressure, the force that blood circulating in the body exerts on the inside of large blood vessels. Blood pressure is highest when the heart is contracts to pump blood out (systolic blood pressure) and lowest when the heart relaxes and refills (diastolic blood pressure). Normal adult blood pressure is defined as a systolic blood pressure of less than 120 millimeters of mercury (mmHg) and a diastolic blood pressure of less than 80 mmHg (a blood pressure of less than 120/80 mmHg). A blood pressure reading of more than 140/90 mmHg indicates hypertension. Many factors affect blood pressure, but overweight people and individuals who eat fatty or salty foods are at high risk of developing hypertension.
Why Was This Study Done?
Most individuals can achieve good hypertension control, which reduces death and disability from cardiovascular and kidney disease, by making lifestyle changes (mild hypertension) and/or by taking antihypertensive drugs. Yet, in both developed and developing countries, many people with hypertension are not aware of their condition and are not adequately treated. As with other chronic diseases, weaknesses in health care systems probably contribute to the inadequate treatment of hypertension. A health care system comprises all the organizations, institutions, and resources whose primary purpose is to improve health. Weaknesses in health care systems can exist at the national, regional, district, community, and household level. In this systematic review (a study that uses predefined criteria to identify all the research on a given topic), the researchers investigate how national and regional health care system arrangements influence hypertension awareness, treatment, and control. Actions that might influence hypertension care at this level of health care systems include providing treatment for hypertension at no or reduced cost, the introduction of financial incentives to healthcare practitioners for the diagnosis and treatment of hypertension, and enhanced insurance coverage in countries such as the US where people pay for health care through insurance policies.
What Did the Researchers Do and Find?
The researchers identified 53 studies that analyzed whether regional or national health care systems arrangements were associated with patient awareness of hypertension, treatment of hypertension, adherence to antihypertensive medication treatment, and control of hypertension. The researchers used an established conceptual framework for health care systems and an approach called narrative synthesis to analyze the results of these studies, most of which were conducted in the US (36 studies) and other high-income countries (eight studies). Nearly all the studies evaluated the effects of health system financing on hypertension outcomes, although several looked at the effects of delivery and governance of health systems on these outcomes. The researchers' analysis revealed an association between reduced medication co-payments (drug costs that are not covered by health insurance and that are paid by patients in countries without universal free healthcare) and improved hypertension control and treatment adherence, mainly in US settings. In addition, in US settings, health insurance coverage was associated with improved hypertension outcomes, as was having a routine physician or place of care.
What Do These Findings Mean?
These findings suggest that minimizing co-payments for health care and expansion of health insurance coverage in countries without universal free health care may improve the awareness, treatment, and control of hypertension. Although these findings are based mainly on US studies, they are likely to apply more generally but, importantly, these findings indicate that additional, high-quality studies are needed to unravel the impact of health systems arrangements on the management of hypertension. In particular, they reveal few studies in low- and middle-income countries where most of the global burden of hypertension lies and where weaknesses in health systems often result in deficiencies in the care of chronic diseases. Moreover, they highlight a need for studies that evaluate how aspects of health care systems other than financing (for example, delivery and governance mechanisms) and interactions between health care system arrangements affect hypertension outcomes. Without the results of such studies, governments and national and international organizations will not know the best ways to deal effectively with the global public-health crisis posed by hypertension.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001490.
The US National Heart Lung and Blood Institute has patient information about high blood pressure (in English and Spanish)
The American Heart Association provides information on high blood pressure (in several languages) and personal stories about dealing with high blood pressure
The UK National Health Service (NHS) Choices website provides detailed information for patients about hypertension and a personal story about hypertension
The World Health Organization provides information on controlling blood pressure and on health systems (in several languages); its "A Global Brief on Hypertension" was published on World Health Day 2013
MedlinePlus provides links to further information about high blood pressure (in English and Spanish)
doi:10.1371/journal.pmed.1001490
PMCID: PMC3728036  PMID: 23935461
3.  Alcohol Intake and Blood Pressure: A Systematic Review Implementing a Mendelian Randomization Approach 
PLoS Medicine  2008;5(3):e52.
Background
Alcohol has been reported to be a common and modifiable risk factor for hypertension. However, observational studies are subject to confounding by other behavioural and sociodemographic factors, while clinical trials are difficult to implement and have limited follow-up time. Mendelian randomization can provide robust evidence on the nature of this association by use of a common polymorphism in aldehyde dehydrogenase 2 (ALDH2) as a surrogate for measuring alcohol consumption. ALDH2 encodes a major enzyme involved in alcohol metabolism. Individuals homozygous for the null variant (*2*2) experience adverse symptoms when drinking alcohol and consequently drink considerably less alcohol than wild-type homozygotes (*1*1) or heterozygotes. We hypothesise that this polymorphism may influence the risk of hypertension by affecting alcohol drinking behaviour.
Methods and Findings
We carried out fixed effect meta-analyses of the ALDH2 genotype with blood pressure (five studies, n = 7,658) and hypertension (three studies, n = 4,219) using studies identified via systematic review. In males, we obtained an overall odds ratio of 2.42 (95% confidence interval [CI] 1.66–3.55, p = 4.8 × 10−6) for hypertension comparing *1*1 with *2*2 homozygotes and an odds ratio of 1.72 (95% CI 1.17–2.52, p = 0.006) comparing heterozygotes (surrogate for moderate drinkers) with *2*2 homozygotes. Systolic blood pressure was 7.44 mmHg (95% CI 5.39–9.49, p = 1.1 × 10−12) greater among *1*1 than among *2*2 homozygotes, and 4.24 mmHg (95% CI 2.18–6.31, p = 0.00005) greater among heterozygotes than among *2*2 homozygotes.
Conclusions
These findings support the hypothesis that alcohol intake has a marked effect on blood pressure and the risk of hypertension.
Using a mendelian randomization approach Sarah Lewis and colleagues find strong support for the hypothesis that alcohol intake has a marked effect on blood pressure and the risk of hypertension.
Editors' Summary
Background.
High blood pressure (hypertension) is a common medical condition that affects nearly a third of US and UK adults. Hypertension has no symptoms but can lead to heart attacks or strokes. It is diagnosed by measuring blood pressure—the force that blood moving around the body exerts on the inside of large blood vessels. Blood pressure is highest when the heart is pumping out blood (systolic pressure) and lowest when it is filling up with blood (diastolic pressure). Normal blood pressure is defined as a systolic pressure of less than 130 millimeters of mercury (mmHg) and a diastolic pressure of less than 85 mmHg (a blood pressure of 130/85). A reading of more than 140/90 indicates hypertension. Many factors affect blood pressure, but overweight people and individuals who eat too much salty or fatty foods are at high risk of developing hypertension. Mild hypertension can often be corrected by lifestyle changes, but many people also take antihypertensive drugs to reduce their blood pressure.
Why Was This Study Done?
Another modifiable lifestyle factor thought to affect blood pressure is alcohol intake. Observational studies that ask people about their drinking habits and measure their blood pressure suggest that alcohol intake correlates with blood pressure, but they cannot prove a causal link because of “confounding”—other risk factors associated with alcohol drinking, such as diet, might also affect the study participant's blood pressures. A trial that randomly assigns people to different alcohol intakes could provide this proof of causality, but such a trial is impractical. In this study, therefore, the researchers have used “Mendelian randomization” to investigate whether alcohol intake affects blood pressure. An inactive variant of aldehyde dehydrogenase 2 (ALDH2; the enzyme that removes alcohol from the body) has been identified. People who inherit the variant form of this gene from both parents have an ALDH2 *2*2 genotype (genetic makeup) and become flushed and nauseated after drinking. Consequently, they drink less than people with a *1*2 genotype and much less than those with a *1*1 genotype. Because inheritance of these genetic variants does not affect lifestyle factors other than alcohol intake, an association between ALDH2 genotypes and blood pressure would indicate that alcohol intake has an effect on blood pressure without any confounding.
What Did the Researchers Do and Find?
The researchers identified ten published studies (mainly done in Japan where the ALDH2 gene variant is common) on associations between ALDH2 genotype and blood pressure or hypertension using a detailed search protocol (a “systematic review”). A meta-analysis (a statistical method for combining the results of independent studies) of the studies that had investigated the association between ALDH2 genotype and hypertension showed that men with the *1*1 genotype (highest alcohol intake) and those with the *1*2 genotype (intermediate alcohol intake) were 2.42 and 1.72 times more likely, respectively, to have hypertension than those with the *2*2 genotype (lowest alcohol intake). There was no association between ALDH2 genotype and hypertension among the women in these studies because they drank very little. Systolic and diastolic blood pressures showed a similar relationship to ALDH2 genotype in a second meta-analysis of relevant studies. Finally, the researchers estimated that for men the lifetime effect of drinking 1 g of alcohol a day (one unit of alcohol contains 8 g of alcohol in the UK and 14 g in the US; recommended daily limits in these countries are 3–4 and 1–2 units, respectively) would be an increase in systolic blood pressure of 0.24 mmHg.
What Do These Findings Mean?
These findings support the suggestion that alcohol has a marked effect on blood pressure and hypertension. Consequently, some cases of hypertension could be prevented by encouraging people to reduce their daily alcohol intake. Although the Mendelian randomization approach avoids most of the confounding intrinsic to observational studies, it is possible that a gene near ALDH2 that has no effect on alcohol intake affects blood pressure, since genes are often inherited in blocks. Alternatively, ALDH2 could affect blood pressure independent of alcohol intake. The possibility that ALDH2 could effect blood pressure independently of alcohol is intake made unlikely by the fact that no effect of genotype on blood pressure is seen among women who drink very little. Additional large-scale studies are needed to address these possibilities, to confirm the current finding in more people, and to improve the estimates of the effect that alcohol intake has on blood pressure.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050052.
The MedlinePlus encyclopedia has a page on hypertension (in English and Spanish)
The American Heart Association provides information for patients and health professionals about hypertension
The UK Blood Pressure Association provides information for patients and health professionals on all aspects of hypertension, including information about alcohol affects blood pressure
The Explore@Bristol science center (a UK charity) provides an alcohol unit calculator and information on the effects of alcohol
The International Center for Alcohol Policies provides drinking guidelines for countries around the world
doi:10.1371/journal.pmed.0050052
PMCID: PMC2265305  PMID: 18318597
4.  Twenty-Four-Hour Ambulatory Blood Pressure Monitoring in Hypertension 
Executive Summary
Objective
The objective of this health technology assessment was to determine the clinical effectiveness and cost-effectiveness of 24-hour ambulatory blood pressure monitoring (ABPM) for hypertension.
Clinical Need: Condition and Target Population
Hypertension occurs when either systolic blood pressure, the pressure in the artery when the heart contracts, or diastolic blood pressure, the pressure in the artery when the heart relaxes between beats, are consistently high. Blood pressure (BP) that is consistently more than 140/90 mmHg (systolic/diastolic) is considered high. A lower threshold, greater than 130/80 mmHg (systolic/diastolic), is set for individuals with diabetes or chronic kidney disease.
In 2006 and 2007, the age-standardized incidence rate of diagnosed hypertension in Canada was 25.8 per 1,000 (450,000 individuals were newly diagnosed). During the same time period, 22.7% of adult Canadians were living with diagnosed hypertension.
A smaller proportion of Canadians are unaware they have hypertension; therefore, the estimated number of Canadians affected by this disease may be higher. Diagnosis and management of hypertension are important, since elevated BP levels are related to the risk of cardiovascular disease, including stroke. In Canada in 2003, the costs to the health care system related to the diagnosis, treatment, and management of hypertension were over $2.3 billion (Cdn).
Technology
The 24-hour ABPM device consists of a standard inflatable cuff attached to a small computer weighing about 500 grams, which is worn over the shoulder or on a belt. The technology is noninvasive and fully automated. The device takes BP measurements every 15 to 30 minutes over a 24-to 28-hour time period, thus providing extended, continuous BP recordings even during a patient’s normal daily activities. Information on the multiple BP measurements can be downloaded to a computer.
The main detection methods used by the device are auscultation and oscillometry. The device avoids some of the pitfalls of conventional office or clinic blood pressure monitoring (CBPM) using a cuff and mercury sphygmomanometer such as observer bias (the phenomenon of measurement error when the observer overemphasizes expected results) and white coat hypertension (the phenomenon of elevated BP when measured in the office or clinic but normal BP when measured outside of the medical setting).
Research Questions
Is there a difference in patient outcome and treatment protocol using 24-hour ABPM versus CBPM for uncomplicated hypertension?
Is there a difference between the 2 technologies when white coat hypertension is taken into account?
What is the cost-effectiveness and budget impact of 24-hour ABPM versus CBPM for uncomplicated hypertension?
Research Methods
Literature Search
Search Strategy
A literature search was performed on August 4, 2011 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 1997 to August 4, 2011. Abstracts were reviewed by a single reviewer. For those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low, or very low according to GRADE methodology.
Inclusion Criteria
English language articles;
published between January 1, 1997 and August 4, 2011;
adults aged 18 years of age or older;
journal articles reporting on the effectiveness, cost-effectiveness, or safety for the comparison of interest;
clearly described study design and methods;
health technology assessments, systematic reviews, meta-analyses, or randomized controlled trials.
Exclusion Criteria
non-English papers;
animal or in vitro studies;
case reports, case series, or case-case studies;
studies comparing different antihypertensive therapies and evaluating their antihypertensive effects using 24-hour ABPM;
studies on home or self-monitoring of BP, and studies on automated office BP measurement;
studies in high-risk subgroups (e.g. diabetes, pregnancy, kidney disease).
Outcomes of Interest
Patient Outcomes
mortality: all cardiovascular events (e.g., myocardial infarction [MI], stroke);
non-fatal: all cardiovascular events (e.g., MI, stroke);
combined fatal and non-fatal: all cardiovascular events (e.g., MI, stroke);
all non-cardiovascular events;
control of BP (e.g. systolic and/or diastolic target level).
Drug-Related Outcomes
percentage of patients who show a reduction in, or stop, drug treatment;
percentage of patients who begin multi-drug treatment;
drug therapy use (e.g. number, intensity of drug use);
drug-related adverse events.
Quality of Evidence
The quality of the body of evidence was assessed as high, moderate, low, or very low according to the GRADE Working Group criteria.
As stated by the GRADE Working Group, the following definitions of quality were used in grading the quality of the evidence:
Summary of Findings
Short-Term Follow-Up Studies (Length of Follow-Up of ≤ 1 Year)
Based on very low quality of evidence, there is no difference between technologies for non-fatal cardiovascular events.
Based on moderate quality of evidence, ABPM resulted in improved BP control among patients with sustained hypertension compared to CBPM.
Based on low quality of evidence, ABPM resulted in hypertensive patients being more likely to stop antihypertensive therapy and less likely to proceed to multi-drug therapy compared to CBPM.
Based on low quality of evidence, there is a beneficial effect of ABPM on the intensity of antihypertensive drug use compared to CBPM.
Based on moderate quality of evidence, there is no difference between technologies in the number of antihypertensive drugs used.
Based on low to very low quality of evidence, there is no difference between technologies in the risk for a drug-related adverse event or noncardiovascular event.
Long-Term Follow-Up Study (Mean Length of Follow-Up of 5 Years)
Based on moderate quality of evidence, there is a beneficial effect of ABPM on total combined cardiovascular events compared to CBPM.
Based on low quality of evidence, there is a lack of a beneficial effect of ABPM on nonfatal cardiovascular events compared to CBPM; however, the lack of a beneficial effect is based on a borderline result.
Based on low quality of evidence, there is no beneficial effect of ABPM on fatal cardiovascular events compared to CBPM.
Based on low quality of evidence, there is no difference between technologies for the number of patients who began multi-drug therapy.
Based on low quality of evidence, there is a beneficial effect of CBPM on control of BP compared to ABPM. This result is in the opposite direction than expected.
Based on moderate quality of evidence, there is no difference between technologies in the risk for a drug-related adverse event.
PMCID: PMC3377518  PMID: 23074425
5.  Blood pressure and incidence of twelve cardiovascular diseases: lifetime risks, healthy life-years lost, and age-specific associations in 1·25 million people 
Lancet  2014;383(9932):1899-1911.
Summary
Background
The associations of blood pressure with the different manifestations of incident cardiovascular disease in a contemporary population have not been compared. In this study, we aimed to analyse the associations of blood pressure with 12 different presentations of cardiovascular disease.
Methods
We used linked electronic health records from 1997 to 2010 in the CALIBER (CArdiovascular research using LInked Bespoke studies and Electronic health Records) programme to assemble a cohort of 1·25 million patients, 30 years of age or older and initially free from cardiovascular disease, a fifth of whom received blood pressure-lowering treatments. We studied the heterogeneity in the age-specific associations of clinically measured blood pressure with 12 acute and chronic cardiovascular diseases, and estimated the lifetime risks (up to 95 years of age) and cardiovascular disease-free life-years lost adjusted for other risk factors at index ages 30, 60, and 80 years. This study is registered at ClinicalTrials.gov, number NCT01164371.
Findings
During 5·2 years median follow-up, we recorded 83 098 initial cardiovascular disease presentations. In each age group, the lowest risk for cardiovascular disease was in people with systolic blood pressure of 90–114 mm Hg and diastolic blood pressure of 60–74 mm Hg, with no evidence of a J-shaped increased risk at lower blood pressures. The effect of high blood pressure varied by cardiovascular disease endpoint, from strongly positive to no effect. Associations with high systolic blood pressure were strongest for intracerebral haemorrhage (hazard ratio 1·44 [95% CI 1·32–1·58]), subarachnoid haemorrhage (1·43 [1·25–1·63]), and stable angina (1·41 [1·36–1·46]), and weakest for abdominal aortic aneurysm (1·08 [1·00–1·17]). Compared with diastolic blood pressure, raised systolic blood pressure had a greater effect on angina, myocardial infarction, and peripheral arterial disease, whereas raised diastolic blood pressure had a greater effect on abdominal aortic aneurysm than did raised systolic pressure. Pulse pressure associations were inverse for abdominal aortic aneurysm (HR per 10 mm Hg 0·91 [95% CI 0·86–0·98]) and strongest for peripheral arterial disease (1·23 [1·20–1·27]). People with hypertension (blood pressure ≥140/90 mm Hg or those receiving blood pressure-lowering drugs) had a lifetime risk of overall cardiovascular disease at 30 years of age of 63·3% (95% CI 62·9–63·8) compared with 46·1% (45·5–46·8) for those with normal blood pressure, and developed cardiovascular disease 5·0 years earlier (95% CI 4·8–5·2). Stable and unstable angina accounted for most (43%) of the cardiovascular disease-free years of life lost associated with hypertension from index age 30 years, whereas heart failure and stable angina accounted for the largest proportion (19% each) of years of life lost from index age 80 years.
Interpretation
The widely held assumptions that blood pressure has strong associations with the occurrence of all cardiovascular diseases across a wide age range, and that diastolic and systolic associations are concordant, are not supported by the findings of this high-resolution study. Despite modern treatments, the lifetime burden of hypertension is substantial. These findings emphasise the need for new blood pressure-lowering strategies, and will help to inform the design of randomised trials to assess them.
Funding
Medical Research Council, National Institute for Health Research, and Wellcome Trust.
doi:10.1016/S0140-6736(14)60685-1
PMCID: PMC4042017  PMID: 24881994
6.  Is blood pressure reduction a valid surrogate endpoint for stroke prevention? an analysis incorporating a systematic review of randomised controlled trials, a by-trial weighted errors-in-variables regression, the surrogate threshold effect (STE) and the biomarker-surrogacy (BioSurrogate) evaluation schema (BSES) 
Background
Blood pressure is considered to be a leading example of a valid surrogate endpoint. The aims of this study were to (i) formally evaluate systolic and diastolic blood pressure reduction as a surrogate endpoint for stroke prevention and (ii) determine what blood pressure reduction would predict a stroke benefit.
Methods
We identified randomised trials of at least six months duration comparing any pharmacologic anti-hypertensive treatment to placebo or no treatment, and reporting baseline blood pressure, on-trial blood pressure, and fatal and non-fatal stroke. Trials with fewer than five strokes in at least one arm were excluded. Errors-in-variables weighted least squares regression modelled the reduction in stroke as a function of systolic blood pressure reduction and diastolic blood pressure reduction respectively. The lower 95% prediction band was used to determine the minimum systolic blood pressure and diastolic blood pressure difference, the surrogate threshold effect (STE), below which there would be no predicted stroke benefit. The STE was used to generate the surrogate threshold effect proportion (STEP), a surrogacy metric, which with the R-squared trial-level association was used to evaluate blood pressure as a surrogate endpoint for stroke using the Biomarker-Surrogacy Evaluation Schema (BSES3).
Results
In 18 qualifying trials representing all pharmacologic drug classes of antihypertensives, assuming a reliability coefficient of 0.9, the surrogate threshold effect for a stroke benefit was 7.1 mmHg for systolic blood pressure and 2.4 mmHg for diastolic blood pressure. The trial-level association was 0.41 and 0.64 and the STEP was 66% and 78% for systolic and diastolic blood pressure respectively. The STE and STEP were more robust to measurement error in the independent variable than R-squared trial-level associations. Using the BSES3, assuming a reliability coefficient of 0.9, systolic blood pressure was a B + grade and diastolic blood pressure was an A grade surrogate endpoint for stroke prevention. In comparison, using the same stroke data sets, no STEs could be estimated for cardiovascular (CV) mortality or all-cause mortality reduction, although the STE for CV mortality approached 25 mmHg for systolic blood pressure.
Conclusions
In this report we provide the first surrogate threshold effect (STE) values for systolic and diastolic blood pressure. We suggest the STEs have face and content validity, evidenced by the inclusivity of trial populations, subject populations and pharmacologic intervention populations in their calculation. We propose that the STE and STEP metrics offer another method of evaluating the evidence supporting surrogate endpoints. We demonstrate how surrogacy evaluations are strengthened if formally evaluated within specific-context evaluation frameworks using the Biomarker- Surrogate Evaluation Schema (BSES3), and we discuss the implications of our evaluation of blood pressure on other biomarkers and patient-reported instruments in relation to surrogacy metrics and trial design.
doi:10.1186/1471-2288-12-27
PMCID: PMC3388460  PMID: 22409774
Blood pressure; Stroke; Surrogate Endpoint; Biomarker
7.  Evaluation of Patients Cooperation in Hypertension Control 
Materia Socio-Medica  2014;26(2):109-111.
Introduction:
Hypertension (high blood pressure) is one of the most widely spread diseases of our time and one of the leading risk factors for heart and vascular diseases, particularly stroke and coronary heart disease. According to the World Health Organization (WHO) cardiovascular diseases are the leading cause of death in the world of who dies each year about 17 million persons, of which 5 million in Europe. The World Health Organization estimates based on monitoring of demographic trends, trends in mortality and morbidity as economic models, further growth of cardiovascular diseases, especially in developing countries.
Goal:
Correlate the success of antihypertensive therapy and provoking factors, and to determine the degree of satisfaction with the effect of antihypertensive therapy of the patient.
Material and methods:
The study was conducted at the Primary Health Care Center Stari Grad - Sarajevo. Conducted is study that included 80 patients. Data for this study were collected by a questionnaire. The questionnaire was completed by the examiner using interviews with patients and their relatives (parents, guardians).After sorting, control and grouping the data were imported into the statistical software package SPSS 20.0, where after defining variables was performed statistical analysis.
Results:
The average age of male respondents was 60.80±13.03 and 63.50 ± 7.48 years of female respondents. The average value of systolic blood pressure amounted to 148mmHg (130-180), while the average value of diastolic blood pressure was 88.75mmHg (70-120). Student's t test showed that the average value of systolic pressure was statistically significantly different from the reference value (t=2.387, DF=19, p=0.028), and also the average values of diastolic blood pressure were statistically significantly different compared to baseline (p=3.561, DF=19, p=0.002). Of the total number of subjects included in this study good blood pressure control had 58 participants, and the average value of systolic blood pressure was 122mmHg and diastolic 74mmHg. With poor regulation of blood pressure were 22 patients, with average values of systolic pressure of 155.5mmHg and diastolic 92 mmHg. The most common additional factor influencing the increase in blood pressure of patients surveyed was stress is 65 % (n=52), followed by heat 20% (n=16), and salty foods was a provoking factor in 15% (n=12) subjects. By analyzing the frequency of controlling blood pressure has been determined that respondents on average control blood pressure once a week, and control frequency is in range from daily to monthly. The average value of the blood pressure of subjects who regularly used antihypertensive therapy amounted to 125/69 mmHg, while the respondents who did not regularly use the antihypertensive therapy that value was 157/96 mmHg.
doi:10.5455/msm.2014.26.109-111
PMCID: PMC4035142  PMID: 24944534
patient; hypertension; therapy
8.  Life Course Trajectories of Systolic Blood Pressure Using Longitudinal Data from Eight UK Cohorts 
PLoS Medicine  2011;8(6):e1000440.
Analysis of eight population-based and occupational cohorts from the UK reveals the patterns of change of blood pressure in the population through the life course.
Background
Much of our understanding of the age-related progression of systolic blood pressure (SBP) comes from cross-sectional data, which do not directly capture within-individual change. We estimated life course trajectories of SBP using longitudinal data from seven population-based cohorts and one predominantly white collar occupational cohort, each from the United Kingdom and with data covering different but overlapping age periods.
Methods and Findings
Data are from 30,372 individuals and comprise 102,583 SBP observations spanning from age 7 to 80+y. Multilevel models were fitted to each cohort. Four life course phases were evident in both sexes: a rapid increase in SBP coinciding with peak adolescent growth, a more gentle increase in early adulthood, a midlife acceleration beginning in the fourth decade, and a period of deceleration in late adulthood where increases in SBP slowed and SBP eventually declined. These phases were still present, although at lower levels, after adjusting for increases in body mass index though adulthood. The deceleration and decline in old age was less evident after excluding individuals who had taken antihypertensive medication. Compared to the population-based cohorts, the occupational cohort had a lower mean SBP, a shallower annual increase in midlife, and a later midlife acceleration. The maximum sex difference was found at age 26 (+8.2 mm Hg higher in men, 95% CI: 6.7, 9.8); women then experienced steeper rises and caught up by the seventh decade.
Conclusions
Our investigation shows a general pattern of SBP progression from childhood in the UK, and suggests possible differences in this pattern during adulthood between a general population and an occupational population.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
About a third of US and UK adults have high blood pressure (hypertension). Although hypertension has no obvious symptoms, it can lead to life-threatening heart attacks, stroke, and other forms of cardiovascular disease (CVD). It is diagnosed by measuring blood pressure—the force that blood moving around the body exerts on the inside of large blood vessels. Blood pressure is highest when the heart is pumping out blood (systolic blood pressure [SBP]) and lowest when the heart is re-filling with blood (diastolic blood pressure [DBP]). Normal adult blood pressure is defined as an SBP of less than 130 millimeters of mercury (mm Hg) and a DBP of less than 85 mm Hg (a blood pressure of 130/85). A reading of more than 140/90 indicates hypertension. Many factors affect blood pressure, but overweight people and individuals who eat fatty or salty food are at high risk of developing hypertension. Moreover, blood pressure tends to increase with age. Mild hypertension can often be corrected by making lifestyle changes, but many people take antihypertensive drugs to reduce their blood pressure.
Why Was This Study Done?
Several trials have indicated that SBP is an important, modifiable risk factor for CVD. But, to determine the best way to prevent CVD, it is important to understand how SBP changes through life and how lifestyle factors affect this age-related progression. Textbook descriptions of age-related changes in SBP are based on studies that measured SBP at a single time point in groups (cohorts) of people of different ages. However, such “cross-sectional” studies do not capture within-individual changes in SBP and may be affected by environmental effects related to specific historical periods. The best way to measure age-related changes in SBP is through longitudinal studies in which SBP is repeatedly measured over many years in a single cohort. Such studies are underway, but it will be some decades before individuals in these studies reach old age. In this study, therefore, the researchers use data from multiple UK cohorts that had repeated SBP measurements taken over different but overlapping periods of life to investigate the life course trajectory of SBP.
What Did the Researchers Do and Find?
The researchers used statistical models to analyze data from longitudinal studies of SBP in seven population-based cohorts (the participants were randomly chosen from the general population) and in one occupational cohort (civil servants). SBP measurements were available for 30,372 individuals with ages spanning from seven years to more than 80 years. The researchers' analysis revealed four phases of SBP change in both sexes: a rapid increase in SBP during adolescent growth, a gentler increase in early adulthood, a midlife acceleration beginning in the fourth decade of life, and a period in late adulthood when SBP increases slowed and then reversed. This last phase was less marked when people taking antihypertensive drugs were excluded from the analysis. After adjusting for increases in body mass index (a measure of body fat) during adulthood, the magnitude of the SBP age-related changes was similar but the average SBP at each age was lower. Compared to the population-based cohorts, the occupational cohort had a lower average SBP, a shallower annual increase in SBP, and a later midlife acceleration, possibly because of socially determined modifiable SBP-related factors such as diet and lifestyle. Finally, although women had lower SBPs in early adulthood than men, they experienced steeper midlife SBP rises (probably because of a menopause-related effect on salt sensitivity) so that by the seventh decade of life, men and women had similar average SBPs.
What Do These Findings Mean?
These findings describe the general pattern of age-related progression of SBP from early childhood in the UK. The findings may not be generalizable because other populations may be exposed to different distributions of modifiable factors. In addition, their accuracy may be affected by differences between cohorts in how SBP was measured. Nevertheless, these findings—in particular, the slower midlife increase in SBP in the occupational cohort than in the population-based cohorts—suggest that the key determinants of age-related increases in blood pressure are modifiable and could be targeted for CVD prevention. Further research is now needed to identify exactly which factors affect the life course trajectory of SBP and to discover when these factors have their greatest influence on SBP.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000440.
The US National Heart Lung and Blood Institute has patient information about high blood pressure (in English and Spanish)
The American Heart Association provides information on high blood pressure and on cardiovascular diseases (in several languages)
The UK National Health Service Choices Web site also provides detailed information for patients about hypertension and about cardiovascular disease
MedlinePlus provides links to further information about high blood pressure, heart disease, and stroke (in English and Spanish)
doi:10.1371/journal.pmed.1000440
PMCID: PMC3114857  PMID: 21695075
9.  Effects of Intensive Blood Pressure Lowering on Cardiovascular and Renal Outcomes: A Systematic Review and Meta-Analysis 
PLoS Medicine  2012;9(8):e1001293.
In a systematic review and meta-analysis Vlado Perkovic and colleagues investigate whether more intensive blood pressure lowering regimens are associated with greater reductions in the risk of major cardiovascular events and end stage kidney disease.
Background
Guidelines recommend intensive blood pressure (BP) lowering in patients at high risk. While placebo-controlled trials have demonstrated 22% reductions in coronary heart disease (CHD) and stroke associated with a 10-mmHg difference in systolic BP, it is unclear if more intensive BP lowering strategies are associated with greater reductions in risk of CHD and stroke. We did a systematic review to assess the effects of intensive BP lowering on vascular, eye, and renal outcomes.
Methods and Findings
We systematically searched Medline, Embase, and the Cochrane Library for trials published between 1950 and July 2011. We included trials that randomly assigned individuals to different target BP levels.
We identified 15 trials including a total of 37,348 participants. On average there was a 7.5/4.5-mmHg BP difference. Intensive BP lowering achieved relative risk (RR) reductions of 11% for major cardiovascular events (95% CI 1%–21%), 13% for myocardial infarction (0%–25%), 24% for stroke (8%–37%), and 11% for end stage kidney disease (3%–18%). Intensive BP lowering regimens also produced a 10% reduction in the risk of albuminuria (4%–16%), and a trend towards benefit for retinopathy (19%, 0%–34%, p = 0.051) in patients with diabetes. There was no clear effect on cardiovascular or noncardiovascular death. Intensive BP lowering was well tolerated; with serious adverse events uncommon and not significantly increased, except for hypotension (RR 4.16, 95% CI 2.25 to 7.70), which occurred infrequently (0.4% per 100 person-years).
Conclusions
Intensive BP lowering regimens provided greater vascular protection than standard regimens that was proportional to the achieved difference in systolic BP, but did not have any clear impact on the risk of death or serious adverse events. Further trials are required to more clearly define the risks and benefits of BP targets below those currently recommended, given the benefits suggested by the currently available data.
Please see later in the article for the Editors' Summary.
Editors' Summary
Background
About a third of US and UK adults have high blood pressure (hypertension). Although hypertension has no obvious symptoms, it can lead to heart attacks, stroke, and other forms of cardiovascular disease, to kidney failure, and to retinopathy (blindness caused by damage to the blood vessels in the back of the eye). Hypertension is diagnosed by measuring blood pressure (BP)—the force that blood moving around the body exerts on the inside of large blood vessels. BP is highest when the heart is pumping out blood (systolic BP) and lowest when it is refilling with blood (diastolic BP). A normal adult BP is defined as a systolic BP of less than 130 millimeters of mercury (mmHg) and a diastolic BP of less than 85 mmHg (a BP of 130/85). A reading of more than 140/90 indicates hypertension. Many factors affect BP, but overweight people and individuals who eat fatty or salty food are at high risk of developing hypertension. Mild hypertension can be corrected by making lifestyle changes, but people often take antihypertensive drugs to reduce their BP.
Why Was This Study Done?
Doctors usually try to reduce the BP of their hypertensive patients to 140/90 mmHg. However, some treatment guidelines now advocate a target BP of 130/80 mmHg for individuals at high risk of life-threatening cardiovascular events, such as people with diabetes or kidney impairment. But does more intensive BP lowering actually reduce the risk of heart attacks and stroke? Although placebo-controlled randomized trials of BP lowering have suggested that a 10 mmHg fall in systolic BP is associated with a 22% reduction in the risk in coronary heart disease and a 41% reduction in the risk of stroke, it is unclear whether intensive BP lowering strategies are associated with greater reductions in the risk of cardiovascular disease than standard strategies. In this systematic review (a search that uses predefined criteria to identify all the research on a given topic) and meta-analysis (a statistical method for combining the results of studies), the researchers investigate the effects of intensive BP lowering on cardiovascular, eye, and renal outcomes.
What Did the Researchers Do and Find?
The researchers identified 15 randomized controlled trials in which more than 37,000 participants were randomly assigned to antihypertensive drug-based strategies designed to achieve different target BPs. On average, the more intensive strategies reduced the BP of participants by 7.5/4.5 mmHg more than the less intensive strategies. Compared to standard BP lowering strategies, more intensive BP lowering strategies reduced the risk of major cardiovascular events (a composite endpoint comprising heart attack, stroke, heart failure, and cardiovascular death) by 11%, the risk of heart attack by 13%, the risk of stroke by 24%, the risk of end-stage kidney disease by 11%, and the risk of albuminuria (protein in the urine, a sign of kidney damage) by 10%. There was also a trend towards a reduced risk for retinopathy with more intensive BP lowering but no clear reduction in cardiovascular or noncardiovascular deaths. Finally, aiming for a lower BP target did not increase the rate of drug discontinuation or the risk of serious adverse events apart from hypotension (very low BP).
What Do These Findings Mean?
These findings suggest that, although intensive BP lowering regimens have no clear effect on the risk of death, they may provide greater protection against cardiovascular events than standard BP lowering regimens. Indeed, the researchers calculate that among every thousand hypertensive patients with a high cardiovascular risk, more intensive BP lowering could prevent two of the 20 cardiovascular events expected to happen every year. Although intensive BP lowering did not seem to increase the risk of severe adverse effects, the accuracy of this finding is limited by inconsistent reporting of adverse events in the trials included in this study. Moreover, because most of the trial participants had additional risk factors for cardiovascular events such as diabetes and chronic kidney disease, these findings may not be generalizable to people with hypertension alone. Thus, although this study suggests that a target BP of 130/80 is likely to produce an additional overall benefit compared to a target of 140/90, more trials are needed to confirm this conclusion and to determine the best way to reach the lower target.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001293.
The US National Heart Lung and Blood Institute has patient information about high blood pressure (in English and Spanish)
The American Heart Association provides information on high blood pressure and on cardiovascular diseases (in several languages); it also provides personal stories from people dealing with high blood pressure
The UK National Health Service (NHS) Choices website also provides detailed information for patients about hypertension, cardiovascular disease and kidney disease; the NHS Local website has a collection of personal stories about hypertension and a series of films that explain hypertension
MedlinePlus provides links to further information about high blood pressure, heart disease, stroke, and kidney disease (in English and Spanish)
doi:10.1371/journal.pmed.1001293
PMCID: PMC3424246  PMID: 22927798
10.  Framingham Heart Study 100K Project: genome-wide associations for blood pressure and arterial stiffness 
BMC Medical Genetics  2007;8(Suppl 1):S3.
Background
About one quarter of adults are hypertensive and high blood pressure carries increased risk for heart disease, stroke, kidney disease and death. Increased arterial stiffness is a key factor in the pathogenesis of systolic hypertension and cardiovascular disease. Substantial heritability of blood-pressure (BP) and arterial-stiffness suggests important genetic contributions.
Methods
In Framingham Heart Study families, we analyzed genome-wide SNP (Affymetrix 100K GeneChip) associations with systolic (SBP) and diastolic (DBP) BP at a single examination in 1971–1975 (n = 1260), at a recent examination in 1998–2001 (n = 1233), and long-term averaged SBP and DBP from 1971–2001 (n = 1327, mean age 52 years, 54% women) and with arterial stiffness measured by arterial tonometry (carotid-femoral and carotid-brachial pulse wave velocity, forward and reflected pressure wave amplitude, and mean arterial pressure; 1998–2001, n = 644). In primary analyses we used generalized estimating equations in models for an additive genetic effect to test associations between SNPs and phenotypes of interest using multivariable-adjusted residuals. A total of 70,987 autosomal SNPs with minor allele frequency ≥ 0.10, genotype call rate ≥ 0.80, and Hardy-Weinberg equilibrium p ≥ 0.001 were analyzed. We also tested for association of 69 SNPs in six renin-angiotensin-aldosterone pathway genes with BP and arterial stiffness phenotypes as part of a candidate gene search.
Results
In the primary analyses, none of the associations attained genome-wide significance. For the six BP phenotypes, seven SNPs yielded p values < 10-5. The lowest p-values for SBP and DBP respectively were rs10493340 (p = 1.7 × 10-6) and rs1963982 (p = 3.3 × 10-6). For the five tonometry phenotypes, five SNPs had p values < 10-5; lowest p-values were for reflected wave (rs6063312, p = 2.1 × 10-6) and carotid-brachial pulse wave velocity (rs770189, p = 2.5 × 10-6) in MEF2C, a regulator of cardiac morphogenesis. We found only weak association of SNPs in the renin-angiotensin-aldosterone pathway with BP or arterial stiffness.
Conclusion
These results of genome-wide association testing for blood pressure and arterial stiffness phenotypes in an unselected community-based sample of adults may aid in the identification of the genetic basis of hypertension and arterial disease, help identify high risk individuals, and guide novel therapies for hypertension. Additional studies are needed to replicate any associations identified in these analyses.
doi:10.1186/1471-2350-8-S1-S3
PMCID: PMC1995621  PMID: 17903302
11.  Zero end-digit preference in recorded blood pressure and its impact on classification of patients for pharmacologic management in primary care — PREDICT-CVD–6 
Background
Most blood pressure recordings end with a zero end-digit despite guidelines recommending measurement to the nearest 2 mmHg. The impact of rounding on management of cardiovascular disease (CVD) risk is unknown.
Aim
To document the use of rounding to zero end-digit and assess its potential impact on eligibility for pharmacologic management of CVD risk.
Design of study
Cross-sectional study.
Setting
A total of 23 676 patients having opportunistic CVD risk assessment in primary care practices in New Zealand.
Method
To simulate rounding in practice, for patients with systolic blood pressures recorded without a zero end-digit, a second blood pressure measure was generated by arithmetically rounding to the nearest zero end-digit. A 10-year Framingham CVD risk score was estimated using actual and rounded blood pressures. Eligibility for pharmacologic treatment was then determined using the Joint British Societies' JBS2 and the British Hypertension Society BHS–IV guidelines based on actual and rounded blood pressure values.
Results
Zero end-digits were recorded in 64% of systolic and 62% of diastolic blood pressures. When eligibility for drug treatment was based only on a Framingham 10-year CVD risk threshold of 20% or more, rounding misclassified one in 41 of all those patients subject to this error. Under the two guidelines which use different combinations of CVD risk and blood pressure thresholds, one in 19 would be misclassified under JBS2 and one in 12 under the BHS–IV guidelines mostly towards increased treatment.
Conclusion
Zero end-digit preference significantly increases a patient's likelihood of being classified as eligible for drug treatment. Guidelines that base treatment decisions primarily on absolute CVD risk are less susceptible to these errors.
PMCID: PMC2169314  PMID: 17976291
blood pressure determination; data quality; decision support systems; evidence-based medicine; practice guidelines; professional practice; risk assessment
12.  Relation of low diastolic blood pressure to coronary heart disease death in presence of myocardial infarction: the Framingham Study. 
BMJ : British Medical Journal  1991;303(6799):385-389.
OBJECTIVE--To examine the hypothesis that a J curve relation between blood pressure and death from coronary heart disease is confined to high risk subjects with myocardial infarction. DESIGN--Cohort longitudinal epidemiological study with biennial examinations since 1950. SETTING--Framingham, Massachusetts, USA. SUBJECTS--5209 subjects in the Framingham study cohort followed up by a person examination approach. MAIN OUTCOME MEASURES--Coronary heart disease deaths and non-cardiovascular disease deaths in men and women with or without myocardial infarction relative to blood pressure. RESULTS--Among subjects without myocardial infarction non-cardiovascular disease deaths were twice to three times as common as coronary heart disease deaths. Furthermore, there was no significant relation between non-cardiovascular disease death and diastolic or systolic blood pressure. Also coronary heart disease deaths were linearly related to diastolic and systolic blood pressures. Among high risk patients (that is, people with myocardial infarction but free of congestive heart failure) death from coronary heart disease was more common than non-cardiovascular disease death. There was a significant U shaped relation between coronary heart disease death and diastolic blood pressure. Although there was an apparent U shaped relation between coronary heart disease death and systolic blood pressure, it did not attain statistical significance when controlling for age and change in systolic blood pressure from the pre-myocardial infarction level. None of the above conclusions changed when adjustments were made for risk factors such as serum cholesterol concentration, antihypertensive treatment, and left ventricular function. The U shaped relation between diastolic blood pressure and high risk subjects existed for both those given antihypertensive treatment and those not. CONCLUSIONS--These data suggest that an age and sex independent U curve relation exists for diastolic blood pressure and coronary heart disease deaths in patients with myocardial infarction but not for low risk subjects without myocardial infarction. The relation seems to be independent of left ventricular function and antihypertensive treatment.
PMCID: PMC1670714  PMID: 1912805
13.  The 2009 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 – therapy 
OBJECTIVE:
To update the evidence-based recommendations for the prevention and management of hypertension in adults for 2009.
OPTIONS AND OUTCOMES:
For lifestyle and pharmacological interventions, evidence from randomized controlled trials and systematic reviews of trials was preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. Progression of kidney dysfunction was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.
EVIDENCE:
A Cochrane collaboration librarian conducted an independent MEDLINE search from 2007 to August 2008 to update the 2008 recommendations. To identify additional published studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.
RECOMMENDATIONS:
For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium to less than 2300 mg (100 mmol)/day (and 1500 mg to 2300 mg [65 mmol to 100 mmol]/day in hypertensive patients); perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (smaller than 102 cm for men and smaller than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a diet that is reduced in saturated fat and cholesterol, and that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and consider stress management in selected individuals with hypertension. For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on by the patient’s global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to lower than 140/90 mmHg in all patients, and to lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. Antihypertensive therapy should be considered in all adult patients regardless of age (caution should be exercised in elderly patients who are frail). For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin-converting enzyme (ACE) inhibitors (in patients who are not black), long-acting calcium channel blockers (CCBs), angiotensin receptor antagonists (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered as the initial treatment of hypertension if the systolic blood pressure is 20 mmHg above the target or if the diastolic blood pressure is 10 mmHg above the target. The combination of ACE inhibitors and ARBs should not be used. Other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine CCBs or ARBs. In patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with proteinuric nondiabetic chronic kidney disease, ACE inhibitors or ARBs (if intolerant to ACE inhibitors) are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.
VALIDATION:
All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.
PMCID: PMC2707169  PMID: 19417859
Antihypertensive drugs; Blood pressure; Guidelines; High blood pressure; Hypertension; Lifestyle interventions
14.  The 2008 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 – therapy 
OBJECTIVE:
To update the evidence-based recommendations for the prevention and management of hypertension in adults.
OPTIONS AND OUTCOMES:
For lifestyle and pharmacological interventions, evidence was preferentially reviewed from randomized controlled trials and systematic reviews of trials. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. Progression of kidney dysfunction was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.
EVIDENCE:
A Cochrane collaboration librarian conducted an independent MEDLINE search from 2006 to August 2007 to update the 2007 recommendations. To identify additional published studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by content and methodological experts using prespecified levels of evidence.
RECOMMENDATIONS:
For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium intake to less than 100 mmol/day (and 65 mmol/day to 100 mmol/day in hypertensive patients); perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (smaller than 102 cm for men and smaller than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a diet that is reduced in saturated fat and cholesterol, and one that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and consider stress management in selected individuals with hypertension. For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on by the patient’s global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to lower than 140/90 mmHg in all patients, and to lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin-converting enzyme (ACE) inhibitors (in nonblack patients), long-acting calcium channel blockers (CCBs), angiotensin receptor antagonists (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered for initial treatment of hypertension if systolic blood pressure is 20 mmHg above target or if diastolic blood pressure is 10 mmHg above target. Other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine CCBs or ARBs. In patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with protein-uric nondiabetic chronic kidney disease, ACE inhibitors are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension but who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.
VALIDATION:
All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.
PMCID: PMC2643190  PMID: 18548143
Antihypertensive drugs; Blood pressure; Guidelines; High blood pressure; Hypertension; Lifestyle interventions
15.  Effect of eprosartan-based antihypertensive therapy on coronary heart disease risk assessed by Framingham methodology in Canadian patients: results of the POWER survey 
Purpose/introduction
The Canadian Hypertension Education Program (CHEP) has identified blood pressure (BP) control as a key target for an overall reduction in cardiovascular disease risk. The POWER survey (Physicians’ Observational Work on Patient Education According to their Vascular Risk) used Framingham methodology to investigate the impact of an angiotensin-receptor-blocker-based regimen on arterial BP and total coronary heart disease (CHD) risk in a subset of patients recruited in Canada.
Methods
309 Canadian practices screened for patients with either newly diagnosed or uncontrolled mild/moderate hypertension (sitting systolic blood pressure [SBP] >140 mmHg with diastolic blood pressure [DBP] <110 mmHg). Treatment comprised eprosartan 600 mg/day with add-on antihypertensive therapy after 1 month if required. The primary efficacy variable was change in SBP at 6 months; the secondary variable was the absolute change in the Framingham 10-year CHD risk score.
Results
1,385 patients were identified, of whom 1,114 were included in the intention-to-treat (ITT) cohort. Thirty-eight point four percent of ITT patients were managed with monotherapy at 6 months, versus 35.2% and 13.7% with two-drug or multiple-drug therapy, respectively. SBP in the ITT cohort declined 22.4 (standard deviation [SD] 14.8) mmHg and DBP declined 10.5 (SD 10.3) mmHg during that time. The absolute mean Framingham score declined 2.1 (SD 3.1) points with significant age and sex variation (P<0.001) and differences between the various Framingham methods used.
Discussion/conclusion
Primary care physicians were able to use a strategy of BP lowering and CHD risk assessment to achieve significant reductions in BP and Framingham-assessed CHD risk. The effect size estimate of the different Framingham methods varied noticeably; reasons for those differences warrant further investigation.
doi:10.2147/VHRM.S55298
PMCID: PMC3908905  PMID: 24493928
blood pressure; hypertension; angiotensin-receptor blocker; observational study
16.  Multivariate generalized multifactor dimensionality reduction to detect gene-gene interactions 
BMC Systems Biology  2013;7(Suppl 6):S15.
Background
Recently, one of the greatest challenges in genome-wide association studies is to detect gene-gene and/or gene-environment interactions for common complex human diseases. Ritchie et al. (2001) proposed multifactor dimensionality reduction (MDR) method for interaction analysis. MDR is a combinatorial approach to reduce multi-locus genotypes into high-risk and low-risk groups. Although MDR has been widely used for case-control studies with binary phenotypes, several extensions have been proposed. One of these methods, a generalized MDR (GMDR) proposed by Lou et al. (2007), allows adjusting for covariates and applying to both dichotomous and continuous phenotypes. GMDR uses the residual score of a generalized linear model of phenotypes to assign either high-risk or low-risk group, while MDR uses the ratio of cases to controls.
Methods
In this study, we propose multivariate GMDR, an extension of GMDR for multivariate phenotypes. Jointly analysing correlated multivariate phenotypes may have more power to detect susceptible genes and gene-gene interactions. We construct generalized estimating equations (GEE) with multivariate phenotypes to extend generalized linear models. Using the score vectors from GEE we discriminate high-risk from low-risk groups. We applied the multivariate GMDR method to the blood pressure data of the 7,546 subjects from the Korean Association Resource study: systolic blood pressure (SBP) and diastolic blood pressure (DBP). We compare the results of multivariate GMDR for SBP and DBP to the results from separate univariate GMDR for SBP and DBP, respectively. We also applied the multivariate GMDR method to the repeatedly measured hypertension status from 5,466 subjects and compared its result with those of univariate GMDR at each time point.
Results
Results from the univariate GMDR and multivariate GMDR in two-locus model with both blood pressures and hypertension phenotypes indicate best combinations of SNPs whose interaction has significant association with risk for high blood pressures or hypertension. Although the test balanced accuracy (BA) of multivariate analysis was not always greater than that of univariate analysis, the multivariate BAs were more stable with smaller standard deviations.
Conclusions
In this study, we have developed multivariate GMDR method using GEE approach. It is useful to use multivariate GMDR with correlated multiple phenotypes of interests.
doi:10.1186/1752-0509-7-S6-S15
PMCID: PMC4029529  PMID: 24565370
17.  The 2007 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 – therapy 
OBJECTIVE:
To provide updated, evidence-based recommendations for the prevention and management of hypertension in adults.
OPTIONS AND OUTCOMES:
For lifestyle and pharmacological interventions, evidence was reviewed from randomized controlled trials and systematic reviews of trials. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. For treatment of patients with kidney disease, the progression of kidney dysfunction was also accepted as a clinically relevant primary outcome.
EVIDENCE:
A Cochrane collaboration librarian conducted an independent MEDLINE search from 2005 to August 2006 to update the 2006 Canadian Hypertension Education Program recommendations. In addition, reference lists were scanned and experts were contacted to identify additional published studies. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.
RECOMMENDATIONS:
Dietary lifestyle modifications for prevention of hypertension, in addition to a well-balanced diet, include a dietary sodium intake of less than 100 mmol/day. In hypertensive patients, the dietary sodium intake should be limited to 65 mmol/day to 100 mmol/day. Other lifestyle modifications for both normotensive and hypertensive patients include: performing 30 min to 60 min of aerobic exercise four to seven days per week; maintaining a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm in men and less than 88 cm in women); limiting alcohol consumption to no more than 14 units per week in men or nine units per week in women; following a diet reduced in saturated fat and cholesterol, and one that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and considering stress management in selected individuals with hypertension.
For the pharmacological management of hypertension, treatment thresholds and targets should take into account each individual’s global atherosclerotic risk, target organ damage and any comorbid conditions: blood pressure should be lowered to lower than 140/90 mmHg in all patients and lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients require more than one agent to achieve these blood pressure targets. In adults without compelling indications for other agents, initial therapy should include thiazide diuretics; other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin-converting enzyme (ACE) inhibitors (except in black patients), long-acting calcium channel blockers (CCBs), angiotensin receptor blockers (ARBs) or beta-blockers (in those younger than 60 years of age). First-line therapy for isolated systolic hypertension includes long-acting dihydropyridine CCBs or ARBs. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction, or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor plus diuretic combination is preferred; in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.
VALIDATION:
All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.
PMCID: PMC2650757  PMID: 17534460
Antihypertensive drugs; Blood pressure; Guidelines; High blood pressure; Hypertension; Lifestyle interventions
18.  Differential control of systolic and diastolic blood pressure in blacks with essential hypertension. 
OBJECTIVE: The risk of cardiovascular and renal diseases has been shown to be higher for systolic blood pressure than diastolic blood pressure. The aim of this study was to assess the differential control of systolic and diastolic blood pressure in Nigerians with primary hypertension. DESIGN AND SETTING: This was a prospective observational study carried out at the Medical Outpatient Department of the State Hospital, Abeokuta, Nigeria. Ethical approval for the study was obtained from the ethical committee of the hospital. METHODOLOGY: The study population consisted of 185 consecutive patients (65 males, 120 females), aged 35-85 years with primary hypertension who had been on drugs one- to 25 years prior to the onset of the study. Clinic blood pressure control was assessed during a year period. Six consecutive clinic blood pressure readings were recorded for each patient and the average calculated (systolic blood pressure and diastolic blood pressure separately). Patients were classified into subgroups based on the pattern of blood pressure control. RESULTS: Clinic systolic blood pressure and diastolic blood pressure was controlled in 58 patients (31.4%). Systolic blood pressure control was less frequent than diastolic blood pressure control (35.7% versus 51.4%, p<0.05). Patients with uncontrolled systolic blood pressure were significantly older than patients with only uncontrolled diastolic blood pressure (66.7+/-7.4 versus 52.9+/-8.7 years, p<0.001). CONCLUSION: Systolic blood pressure is less frequently controlled than diastolic blood pressure in Nigerians treated for primary hypertension. This may increase the patient's risk of developing stroke, and cardiovascular and renal complications.
PMCID: PMC2594866  PMID: 15040512
19.  Analysis of gene × environment interactions in sibships using mixed models 
BMC Genetics  2003;4(Suppl 1):S18.
Background
Gene × environment models are widely used to assess genetic and environmental risks and their association with a phenotype of interest for many complex diseases. Mixed generalized linear models were used to assess gene × environment interactions with respect to systolic blood pressure on sibships adjusting for repeated measures and hierarchical nesting structures. A data set containing 410 sibships from the Framingham Heart Study offspring cohort (part of the Genetic Analysis Workshop 13 data) was used for all analyses. Three mixed gene × environment models, all adjusting for repeated measurement and varying levels of nesting, were compared for precision of estimates: 1) all sibships with adjustment for two levels of nesting (sibs within sibships and sibs within pedigrees), 2) all sibships with adjustment for one level of nesting (sibs within sibships), and 3) 100 data sets containing random draws of one sibship per extended pedigree adjusting for one level of nesting.
Results
The main effects were: gender, baseline age, body mass index (BMI), hypertensive treatment, cigarettes per day, grams of alcohol per day, and marker GATA48G07A. The interaction fixed effects were: baseline age by gender, baseline age by cigarettes per day, baseline age by hypertensive treatment, baseline age by BMI, hypertensive treatment by BMI, and baseline age by marker GATA48G07A. The estimates for all three nesting techniques were not widely discrepant, but precision of estimates and determination of significant effects did change with the change in adjustment for nesting.
Conclusion
Our results show the importance of the adjustment for all levels of hierarchical nesting of sibs in the presence of repeated measures.
doi:10.1186/1471-2156-4-S1-S18
PMCID: PMC1866452  PMID: 14975086
20.  The 2010 Canadian Hypertension Education Program recommendations for the management of hypertension: Part 2 – therapy 
OBJECTIVE:
To update the evidence-based recommendations for the prevention and treatment of hypertension in adults for 2010.
OPTIONS AND OUTCOMES:
For lifestyle and pharmacological interventions, randomized trials and systematic reviews of trials were preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the general lack of long-term morbidity and mortality data in this field. Progressive renal impairment was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.
EVIDENCE:
A Cochrane Collaboration librarian conducted an independent MEDLINE search from 2008 to August 2009 to update the 2009 recommendations. To identify additional studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.
RECOMMENDATIONS:
For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium to 1500 mg (65 mmol) per day in adults 50 years of age or younger, to 1300 mg (57 mmol) per day in adults 51 to 70 years of age, and to 1200 mg (52 mmol) per day in adults older than 70 years of age; perform 30 min to 60 min of moderate aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 standard drinks per week for men or nine standard drinks per week for women; follow a diet that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources, and that is low in saturated fat and cholesterol; and consider stress management in selected individuals with hypertension.
For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on the patient’s global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to less than 140/90 mmHg in all patients, and to less than 130/80 mmHg in patients with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. Antihypertensive therapy should be considered in all adult patients regardless of age (caution should be exercised in elderly patients who are frail). For adults without compelling indications for other agents, considerations for initial therapy should include thiazide diuretics, angiotensin-converting enzyme (ACE) inhibitors (in patients who are not black), long-acting calcium channel blockers (CCBs), angiotensin receptor blockers (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered as initial treatment of hypertension if systolic blood pressure is 20 mmHg above target or if diastolic blood pressure is 10 mmHg above target. The combination of ACE inhibitors and ARBs should not be used, unless compelling indications are present to suggest consideration of dual therapy.
Agents appropriate for first-line therapy for isolated systolic hypertension include thiazide diuretics, long-acting dihydropyridine CCBs or ARBs. In patients with coronary artery disease, ACE inhibitors, ARBs or beta-blockers are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with proteinuric nondiabetic chronic kidney disease, ACE inhibitors or ARBs (if intolerant to ACE inhibitors) are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. In selected high-risk patients in whom combination therapy is being considered, an ACE inhibitor plus a long-acting dihydropyridine CCB is preferable to an ACE inhibitor plus a thiazide diuretic. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian lipid treatment guidelines. Selected patients with hypertension who do not achieve thresholds for statin therapy, but who are otherwise at high risk for cardiovascular events, should nonetheless receive statin therapy. Once blood pressure is controlled, low-dose acetylsalicylic acid therapy should be considered.
VALIDATION:
All recommendations were graded according to the strength of the evidence and voted on by the 63 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 80% consensus. These guidelines will continue to be updated annually.
SPONSORS:
The Canadian Hypertension Education Program process is sponsored by the Canadian Hypertension Society, Blood Pressure Canada, the Public Health Agency of Canada, the College of Family Physicians of Canada, the Canadian Pharmacists Association, the Canadian Council of Cardiovascular Nurses, and the Heart and Stroke Foundation of Canada.
PMCID: PMC2886555  PMID: 20485689
Antihypertensive drugs; Blood pressure; Guidelines; High blood pressure; Hypertension; Lifestyle interventions
21.  Genetic linkage analysis of longitudinal hypertension phenotypes using three summary measures 
BMC Genetics  2003;4(Suppl 1):S24.
Background
Longitudinal data often have multiple (repeated) measures recorded along a time trajectory. For example, the two cohorts from the Framingham Heart Study (GAW13 Problem 1) contain 21 and 5 repeated measures for hypertension phenotypes as well as epidemiological risk factors, respectively. Direct modelling of a large number of serially and biologically correlated traits in the context of linkage analysis can be prohibitively complex. Alternatively, we may consider using univariate transformation for linkage analysis of longitudinal repeated measures.
Results
We evaluated the utility of three conventional summary measures (mean, slope, and principal components) for genetic linkage analysis of longitudinal phenotypes by analyzing the chromosome 10 data of the Framingham Heart Study. Except for the temporal slope, all of the summary methods and the multivariate analysis identified the previously reported region, marker GATA64A09, for systolic blood pressure or high blood pressure. Further analysis revealed that this region may harbor gene(s) affecting human blood pressure at multiple stages of life.
Conclusion
We conclude that mean and principal components are feasible alternatives for genetic linkage analysis of longitudinal phenotypes, but the slope might have a separate genetic basis from that of the original longitudinal phenotypes.
doi:10.1186/1471-2156-4-S1-S24
PMCID: PMC1866459  PMID: 14975092
22.  The impact of a cardiovascular health awareness program (CHAP) on reducing blood pressure: a prospective cohort study 
BMC Public Health  2013;13:1230.
Background
Hypertension is an important and modifiable cardiovascular risk factor that remains under-detected and under-treated, especially in the older individuals. Community-led interventions that integrate primary health care and local resources are promising approaches to improve awareness and management of hypertension and other cardiovascular risk factors. We aimed to evaluate the effect of a community-based Cardiovascular Health Awareness Program (CHAP) on participants’ blood pressure.
Methods
This study followed a cohort of community residents that participated in CHAP across 22 mid-sized Ontario communities over an 18-month period. The participants’ baseline risk factors, including blood pressure, and subsequent measures of blood pressure were recorded. We employed a bivariate linear mixed-effect model to estimate the change of systolic and diastolic blood pressure over time among the participants who attended more than two CHAP sessions.
Results
Of 13,596 participants, 2498 attended more than two CHAP sessions. For those repeated participants (attending more than two sessions) initially identified with high blood pressure, the average reduction of systolic blood pressure was from 142 to 123 mmHg over an 18-month period, a monthly rate ratio of 0.992 (95% CI: 0.991,0.994; p < 0.01). Similarly, the average reduction of diastolic blood pressure was from 78 to 69 mmHg, a monthly rate ratio of 0.993 (95% CI: 0.991,0.994; p < 0.01). The average blood pressure of the participants with normal baseline blood pressure remained controlled and unchanged. We also found that older adult participants who lived alone, were diagnosed with hypertension, reported healthier eating habits, and presented with a higher baseline systolic blood pressure had significantly greater odds of attending more than one session.
Conclusions
CHAP was associated with a reduction in systolic and diastolic blood pressure for those participants who attended more than one session. The magnitude of blood pressure reductions was significant clinically and statistically.
doi:10.1186/1471-2458-13-1230
PMCID: PMC3883556  PMID: 24369050
23.  Body mass index and cardiovascular mortality at different levels of blood pressure: a prospective study of Norwegian men and women. 
STUDY OBJECTIVE--The study investigated the joint effect of body mass index and systolic blood pressure on cardiovascular and total mortality. DESIGN--This was a prospective cohort study. The main outcome measures were age adjusted mortality and relative risks estimated from survival models. SETTING--The population of the city of Bergen, Norway. PARTICIPANTS--Subjects were 21,145 men and 30,330 women aged 30-79 years at the time of examination in 1963. MAIN RESULTS--Both cause specific and all cause mortality increased with systolic blood pressure within each category of body mass index. Stroke mortality was not significantly associated with body mass index when adjusted for systolic blood pressure in either age group of men or women. Coronary heart disease mortality increased on average 30% per 5 kg/m2 increase in body mass index in men and women aged 30-59 years at baseline. Adjusted for systolic blood pressure, the relative risks were reduced to 1.20 (95% confidence interval (CI) 1.12, 1.29) in men and 1.10 (95% CI 1.03, 1.18) in women. They were similar at each level of systolic blood pressure. For coronary heart disease mortality in men and women aged 60-79 years at measurement a negative interaction between body mass index and systolic blood pressure was suggested in the first five years. Excluding the first five years, adjusted relative risks per 5 kg/m2, were 1.05 (95% CI 0.96, 1.15) in men and 1.11 (95% CI 1.04, 1.17) in women in the older age group. There was an upturn in cardiovascular mortality at low levels of body mass index in both age groups of women, but not in men. CONCLUSIONS--Hypertension is an important risk factor for cardiovascular and all cause mortality even in the obese. Body mass index is generally a weak predictor of cardiovascular mortality in this population. It is a stronger risk factor of coronary death in men when measured at a younger age. Thin people with hypertension are not at particularly high risk of death from coronary heart disease compared with their obese counterparts, except possibly in the first few years after measurement in the elderly. Being underweight is associated with increased risk of death from all cardiovascular causes in women, but not in men.
PMCID: PMC1060795  PMID: 7629461
24.  Analysing the socioeconomic determinants of hypertension in South Africa: a structural equation modelling approach 
BMC Public Health  2014;14:414.
Background
Epidemiological research has long observed a varying prevalence of hypertension across socioeconomic strata. However, patterns of association and underlying causal mechanisms are poorly understood in sub-Saharan Africa. Using education and income as indicators, we investigated the extent to which socioeconomic status is linked to blood pressure in the first wave of the National Income Dynamics Study — a South African longitudinal study of more than 15000 adults – and whether bio-behavioural risk factors mediate the association.
Methods
In a cross-sectional analysis, structural equation modelling was employed to estimate the effect of socioeconomic status on systolic and diastolic blood pressure and to assess the role of a set of bio-behavioural risk factors in explaining the observed relationships.
Results
After adjustment for age, race and antihypertensive treatment, higher education and income were independently associated with higher diastolic blood pressure in men. In women higher education predicted lower values of both diastolic and systolic blood pressure while higher income predicted lower systolic blood pressure. In both genders, body mass index was a strong mediator of an adverse indirect effect of socioeconomic status on blood pressure. Together with physical exercise, alcohol use, smoking and resting heart rate, body mass index therefore contributed substantially to mediation of the observed relationships in men. By contrast, in women unmeasured factors played a greater role.
Conclusion
In countries undergoing epidemiological transition, effects of socioeconomic status on blood pressure may vary by gender. In women, factors other than those listed above may have substantial role in mediating the association and merit investigation.
doi:10.1186/1471-2458-14-414
PMCID: PMC4021547  PMID: 24885860
Systolic blood pressure; Diastolic blood pressure; Hypertension; Body mass index; Socioeconomic status; Sub-Saharan Africa; Structural equation modelling
25.  The Effect of Hypertension and Diabetes Management in Southwest China: A Before- and After-Intervention Study 
PLoS ONE  2014;9(3):e91801.
Background
Non-communicable diseases are leading causes of disease burden in middle income countries. Little evidence exists to determine if the primary healthcare system can effectively manage non-communicable diseases. The purpose of this study was to examine the effectiveness of hypertension and diabetes management by the primary healthcare system.
Methods
We used individual level data from the 2009 National Basic Public Health Services System to assess the effectiveness of hypertension and diabetes interventions on fasting plasma glucose, and blood pressure. We analyzed the associations between fasting plasma glucose, systolic or diastolic blood pressure and risk factors. The estimated average intervention effect on data balanced with confounding variables was assessed.
Results
9543 individuals who had data for fasting plasma glucose, systolic blood pressure and diastolic blood pressure were included in this analysis. This study included 6681 patients with hypertension and 2222 with diabetes. The intervention lowered mean fasting plasma glucose by 0.5 mmol/L (0.4–0.6), lowered mean systolic blood pressure by 3.5 mm Hg (3.2–3.7), and lowered diastolic blood pressure by 2.9 mm Hg (2.7–3.2). Individuals who received medicinal treatment had 1.3 mmHg (0.8 to 1.8, P<0.01) lower diastolic blood pressure and 0.6 mmol/L (0.5–0.8, P<0.01) lower fasting plasma glucose than those who did not receive medicine. Generalized linear model indicated that medicinal treatment and baseline systolic blood pressure were significant positive predictors of change in systolic blood pressure. Age, living in urban areas and diabetic complications were significant negative predictors of change for systolic blood pressure.
Conclusion
The National Basic Public Health Services System in China using trained community healthcare workers and well-established guidelines can be effectively implement non-communicable disease prevention and management care paradigms.
doi:10.1371/journal.pone.0091801
PMCID: PMC3954760  PMID: 24632720

Results 1-25 (1239887)