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1.  24 hour blood pressure monitoring in healthy and hypertensive children. 
24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.
PMCID: PMC1029706  PMID: 8129450
2.  Caffeine restriction: effect on mild hypertension. 
BMJ : British Medical Journal  1991;303(6812):1235-1238.
OBJECTIVE--To determine the effects on blood pressure of modifying dietary caffeine intake in patients with mild and borderline hypertension by monitoring ambulatory and clinic blood pressure. DESIGN--Four way, randomised, crossover trial of four consecutive two week dietary regimens: normal diet, caffeine free diet alone, caffeine free diet with decaffeinated instant coffee, caffeine free diet with caffeinated instant coffee (instant coffee phases conducted double blind). SETTING--Hospital hypertension clinic, Scotland. PATIENTS--52 patients (23 men; aged 26-67 years) with untreated borderline or mild hypertension (diastolic blood pressure 90-105 mm Hg) who normally drank a minimum of three cups of coffee daily. MAIN OUTCOME MEASURES--Mean ambulatory blood pressure over 24 hours; mean morning, daytime, and night time ambulatory blood pressure; sitting clinic blood pressure at 1700; plasma caffeine concentration at 1700 on the last day of each regimen. RESULTS--Mean 24 hour ambulatory blood pressure was not different between regimens. There was no difference in blood pressure variability between regimens. During the caffeine free diet alone morning ambulatory diastolic blood pressure was higher (2.8 mm Hg) than during the caffeine free diet with caffeinated coffee. Mean sitting clinic systolic blood pressure was higher at 1700 (4.7 mm Hg) with a caffeine free diet than with the caffeine free diet with caffeinated coffee (p less than 0.05). Dietary compliance as assessed by plasma caffeine concentration was excellent. There was no significant correlation between plasma caffeine concentration and blood pressure. CONCLUSIONS--Drinking caffeinated instant coffee over a two week period does not adversely influence blood pressure in patients with borderline or mild hypertension; abstinence is of no benefit.
PMCID: PMC1671547  PMID: 1747643
3.  Day/Night Variability in Blood Pressure: Influence of Posture and Physical Activity 
American Journal of Hypertension  2013;26(6):822-828.
BACKGROUND
Blood pressure (BP) is highest during the day and lowest at night. Absence of this rhythm is a predictor of cardiovascular morbidity and mortality. Contributions of changes in posture and physical activity to the 24-hour day/night rhythm in BP are not well understood. We hypothesized that postural changes and physical activity contribute substantially to the day/night rhythm in BP.
METHODS
Fourteen healthy, sedentary, nonobese, normotensive men (aged 19–50 years) each completed an ambulatory and a bed rest condition during which BP was measured every 30–60 minutes for 24 hours. When ambulatory, subjects followed their usual routines without restrictions to capture the “normal” condition. During bed rest, subjects were constantly confined to bed in a 6-degree head-down position; therefore posture was constant, and physical activity was minimized. Two subjects were excluded from analysis because of irregular sleep timing.
RESULTS
The systolic and diastolic BP reduction during the sleep period was similar in ambulatory (−11±2mmHg/−8±1mmHg) and bed rest conditions (−8±3mmHg/−4±2mmHg; P = 0.38/P = 0.12). The morning surge in diastolic BP was attenuated during bed rest (P = 0.001), and there was a statistical trend for the same effect in systolic BP (P = 0.06).
CONCLUSIONS
A substantial proportion of the 24-hour BP rhythm remained during bed rest, indicating that typical daily changes in posture and/or physical activity do not entirely explain 24-hour BP variation under normal ambulatory conditions. However, the morning BP increase was attenuated during bed rest, suggesting that the adoption of an upright posture and/or physical activity in the morning contributes to the morning BP surge.
doi:10.1093/ajh/hpt026
PMCID: PMC3693479  PMID: 23535155
ambulatory; bed rest; blood pressure; circadian; hypertension; sleep.
4.  Blood Pressure Measurements Taken by Patients are Similar to Home and Ambulatory Blood Pressure Measurements 
Clinics (Sao Paulo, Brazil)  2008;63(1):43-50.
OBJECTIVE
To compare blood pressure measurements taken at home by physicians, nurses, and patients with office blood pressure measurement , ambulatory blood pressure monitoring and home blood pressure measurement.
METHODS
A total of 44 patients seen by a home care program were studied. Protocol 1 a) blood pressure was measured by the patient, a physician and a nurse during a regular home visit (Home1); b) home blood pressure measurement was measured for 4 days (HBPM1); c) office blood pressure measurement was measured by a physician, a nurse, and the patient; and by 24-hour ambulatory blood pressure monitoring. Protocol 2 blood pressure was measured by the patient, a physician, and a nurse during a special home visit in the presence of a physician and a nurse only (Home2); and b) home blood pressure measurement was taken for the second time (HBPM2). Echocardiography, guided by a two-dimensional echocardiograph, was performed.
RESULTS
Protocol 1: a) office blood pressure measurement and Home1 were significantly higher than ambulatory blood pressure monitoring, except for systolic and diastolic office blood pressure measurement taken by the patient or a family member, systolic blood pressure taken by a nurse, and diastolic blood pressure taken by a physician. b) ambulatory blood pressure monitoring and HBPM1 were similar. Protocol 2: a) HBPM2 and Home2 were similar. b) Home2 was significantly lower than Home1, except for diastolic blood pressure taken by a nurse or the patient. There were significant relationships between: a) diastolic blood pressure measured by the patient and the thickness of the interventricular septum, posterior wall, and left ventricular mass; and b) ambulatory and HBPM2 diastolic and systolic blood pressure taken by a physician (home2) and left ventricular mass. Therefore, the data indicate that home blood pressure measurement and ambulatory blood pressure monitoring had good prognostic values relative to “office measurement.”
CONCLUSION
This study showed that the measurement most similar to home blood pressure measurement and ambulatory blood pressure monitoring was blood pressure measured by the patient, and that home blood pressure measurement and ambulatory blood pressure monitoring had good prognostic value relative to “office measurements”.
PMCID: PMC2664186  PMID: 18297206
Home blood pressure; Ambulatory blood pressure; Office blood pressure measurement; Hypertension; White coat effect
5.  Ambulatory Blood Pressure Monitoring in Clinical Practice: A Review 
The American journal of medicine  2014;128(1):14-20.
Ambulatory blood pressure monitoring offers the ability to collect blood pressure readings several times an hour across a 24-hour period. Ambulatory blood pressure monitoring facilitates the identification of white-coat hypertension, the phenomenon whereby certain individuals who are not on antihypertensive medication show elevated blood pressure in a clinical setting but show non-elevated blood pressure averages when assessed by ambulatory blood pressure monitoring. Additionally, readings can be segmented into time windows of particular interest, e.g., mean daytime and nighttime values. During sleep, blood pressure typically decreases, or dips, such that mean sleep blood pressure is lower than mean awake blood pressure. A non-dipping pattern and nocturnal hypertension are strongly associated with increased cardiovascular morbidity and mortality. Approximately 70% of individuals dip ≥10% at night, while 30% have non-dipping patterns, when blood pressure remains similar to daytime average, or occasionally rises above daytime average. The various blood pressure categorizations afforded by ambulatory blood pressure monitoring are valuable for clinical management of high blood pressure since they increase accuracy for diagnosis and the prediction of cardiovascular risk.
doi:10.1016/j.amjmed.2014.07.021
PMCID: PMC4877527  PMID: 25107387
high blood pressure; ambulatory blood pressure monitoring; white-coat hypertension; masked hypertension; nocturnal blood pressure
6.  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
7.  Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial 
Objective To compare the quality and accuracy of manual office blood pressure and automated office blood pressure using the awake ambulatory blood pressure as a gold standard.
Design Multi-site cluster randomised controlled trial.
Setting Primary care practices in five cities in eastern Canada.
Participants 555 patients with systolic hypertension and no serious comorbidities under the care of 88 primary care physicians in 67 practices in the community.
Interventions Practices were randomly allocated to either ongoing use of manual office blood pressure (control group) or automated office blood pressure (intervention group) using the BpTRU device. The last routine manual office blood pressure (mm Hg) was obtained from each patient’s medical record before enrolment. Office blood pressure readings were compared before and after enrolment in the intervention and control groups; all readings were also compared with the awake ambulatory blood pressure.
Main outcome measure Difference in systolic blood pressure between awake ambulatory blood pressure minus automated office blood pressure and awake ambulatory blood pressure minus manual office blood pressure.
Results Cluster randomisation allocated 31 practices (252 patients) to manual office blood pressure and 36 practices (303 patients) to automated office blood pressure measurement. The most recent routine manual office blood pressure (149.5 (SD 10.8)/81.4 (8.3)) was higher than automated office blood pressure (135.6 (17.3)/77.7 (10.9)) (P<0.001). In the control group, routine manual office blood pressure before enrolment (149.9 (10.7)/81.8 (8.5)) was reduced to 141.4 (14.6)/80.2 (9.5) after enrolment (P<0.001/P=0.01), but the reduction in the intervention group from manual office to automated office blood pressure was significantly greater (P<0.001/P=0.02). On the first study visit after enrolment, the estimated mean difference for the intervention group between the awake ambulatory systolic/diastolic blood pressure and automated office blood pressure (−2.3 (95% confidence interval −0.31 to −4.3)/−3.3 (−2.7 to −4.4)) was less (P=0.006/P=0.26) than the difference in the control group between the awake ambulatory blood pressure and the manual office blood pressure (−6.5 (−4.3 to −8.6)/−4.3 (−2.9 to −5.8)). Systolic/diastolic automated office blood pressure showed a stronger (P<0.001) within group correlation (r=0.34/r=0.56) with awake ambulatory blood pressure after enrolment compared with manual office blood pressure versus awake ambulatory blood pressure before enrolment (r=0.10/r= 0.40); the mean difference in r was 0.24 (0.12 to 0.36)/0.16 (0.07 to 0.25)). The between group correlation comparing diastolic automated office blood pressure and awake ambulatory blood pressure (r=0.56) was stronger (P<0.001) than that for manual office blood pressure versus awake ambulatory blood pressure (r=0.30); the mean difference in r was 0.26 (0.09 to 0.41). Digit preference with readings ending in zero was substantially reduced by use of automated office blood pressure.
Conclusion In compliant, otherwise healthy, primary care patients with systolic hypertension, introduction of automated office blood pressure into routine primary care significantly reduced the white coat response compared with the ongoing use of manual office blood pressure measurement. The quality and accuracy of automated office blood pressure in relation to the awake ambulatory blood pressure was also significantly better when compared with manual office blood pressure.
Trial registration Clinical trials NCT 00214053.
doi:10.1136/bmj.d286
PMCID: PMC3034423  PMID: 21300709
8.  Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial 
The BMJ  2011;342:d286.
Objective To compare the quality and accuracy of manual office blood pressure and automated office blood pressure using the awake ambulatory blood pressure as a gold standard.
Design Multi-site cluster randomised controlled trial.
Setting Primary care practices in five cities in eastern Canada.
Participants 555 patients with systolic hypertension and no serious comorbidities under the care of 88 primary care physicians in 67 practices in the community.
Interventions Practices were randomly allocated to either ongoing use of manual office blood pressure (control group) or automated office blood pressure (intervention group) using the BpTRU device. The last routine manual office blood pressure (mm Hg) was obtained from each patient’s medical record before enrolment. Office blood pressure readings were compared before and after enrolment in the intervention and control groups; all readings were also compared with the awake ambulatory blood pressure.
Main outcome measure Difference in systolic blood pressure between awake ambulatory blood pressure minus automated office blood pressure and awake ambulatory blood pressure minus manual office blood pressure.
Results Cluster randomisation allocated 31 practices (252 patients) to manual office blood pressure and 36 practices (303 patients) to automated office blood pressure measurement. The most recent routine manual office blood pressure (149.5 (SD 10.8)/81.4 (8.3)) was higher than automated office blood pressure (135.6 (17.3)/77.7 (10.9)) (P<0.001). In the control group, routine manual office blood pressure before enrolment (149.9 (10.7)/81.8 (8.5)) was reduced to 141.4 (14.6)/80.2 (9.5) after enrolment (P<0.001/P=0.01), but the reduction in the intervention group from manual office to automated office blood pressure was significantly greater (P<0.001/P=0.02). On the first study visit after enrolment, the estimated mean difference for the intervention group between the awake ambulatory systolic/diastolic blood pressure and automated office blood pressure (−2.3 (95% confidence interval −0.31 to −4.3)/−3.3 (−2.7 to −4.4)) was less (P=0.006/P=0.26) than the difference in the control group between the awake ambulatory blood pressure and the manual office blood pressure (−6.5 (−4.3 to −8.6)/−4.3 (−2.9 to −5.8)). Systolic/diastolic automated office blood pressure showed a stronger (P<0.001) within group correlation (r=0.34/r=0.56) with awake ambulatory blood pressure after enrolment compared with manual office blood pressure versus awake ambulatory blood pressure before enrolment (r=0.10/r= 0.40); the mean difference in r was 0.24 (0.12 to 0.36)/0.16 (0.07 to 0.25)). The between group correlation comparing diastolic automated office blood pressure and awake ambulatory blood pressure (r=0.56) was stronger (P<0.001) than that for manual office blood pressure versus awake ambulatory blood pressure (r=0.30); the mean difference in r was 0.26 (0.09 to 0.41). Digit preference with readings ending in zero was substantially reduced by use of automated office blood pressure.
Conclusion In compliant, otherwise healthy, primary care patients with systolic hypertension, introduction of automated office blood pressure into routine primary care significantly reduced the white coat response compared with the ongoing use of manual office blood pressure measurement. The quality and accuracy of automated office blood pressure in relation to the awake ambulatory blood pressure was also significantly better when compared with manual office blood pressure.
Trial registration Clinical trials NCT 00214053.
doi:10.1136/bmj.d286
PMCID: PMC3034423  PMID: 21300709
9.  Effect of stress management on blood pressure in mild primary hypertension. 
BMJ : British Medical Journal  1993;306(6883):963-966.
OBJECTIVE--To establish whether stress management had a larger effect than a control treatment on resting blood pressure, ambulatory blood pressure, and left ventricular mass. DESIGN--A 12 week baseline period of habituation to measurement of blood pressure was followed by randomisation to either stress management or mild exercise for six months and follow up six months later. SETTING--General practice, district general hospital, and medical school. PATIENTS--Of the 184 patients aged under 60 with mild primary hypertension who entered the baseline habituation period, 88 were excluded because they failed to meet the entry criteria or they withdrew from the study. The remaining 46 men and 50 women underwent treatment. INTERVENTIONS--10 clinical sessions and daily practice at home of either stress management based on relaxation or non-aerobic stretching exercises. Mildly stressful 15 minute interviews before and after treatment. MAIN OUTCOME MEASURES--Diastolic and systolic blood pressure in the clinic and during 12 hours of ambulatory recording, and left ventricular mass measured by echocardiography. RESULTS--The patients' blood pressure fell during habituation (systolic pressure from 152 mmHg to 140 mmHg, diastolic pressure from 98 to 93 mm Hg), but neither resting nor ambulatory blood pressure was changed by the treatments. Left ventricular mass was also unchanged. Blood pressure rose during the stressful interview, but this rise was reduced by stress management (systolic pressure rose by 7.4 mmHg before treatment and by 3.7 mmHg after treatment). CONCLUSION--Stress management of a type advocated for treating mild primary hypertension is ineffective in lowering blood pressure in patients who are well habituated to measuring blood pressure.
PMCID: PMC1677411  PMID: 8490471
10.  Comparison of agreement between different measures of blood pressure in primary care and daytime ambulatory blood pressure 
BMJ : British Medical Journal  2002;325(7358):254.
Objective
To assess alternatives to measuring ambulatory pressure, which best predicts response to treatment and adverse outcome.
Setting
Three general practices in England.
Design
Validation study.
Participants
Patients with newly diagnosed high or borderline high blood pressure; patients receiving treatment for hypertension but with poor control.
Main outcome measures
Overall agreement with ambulatory pressure; prediction of high ambulatory pressure (>135/85 mm Hg) and treatment thresholds.
Results
Readings made by doctors were much higher than ambulatory systolic pressure (difference 18.9 mm Hg, 95% confidence interval 16.1 to 21.7), as were recent readings made in the clinic outside research settings (19.9 mm Hg,17.6 to 22.1). This applied equally to treated patients with poor control (doctor v ambulatory 21.4 mm Hg, 17.3 to 25.4). Doctors' and recent clinic readings ranked systolic pressure poorly compared with ambulatory pressure and other measurements (doctor r=0.46; clinic 0.47; repeated readings by nurse 0.60; repeated self measurement 0.73; home readings 0.75) and were not specific at predicting high blood pressure (doctor 26%; recent clinic 15%; nurse 72%; patient in surgery 81%; home 60%), with poor likelihood ratios for a positive test (doctor 1.2; clinic 1.1; nurse 2.1, patient in surgery 4.7; home 2.2). Nor were doctor or recent clinic measures specific in predicting treatment thresholds.
Conclusion
The “white coat” effect is important in diagnosing and assessing control of hypertension in primary care and is not a research artefact. If ambulatory or home measurements are not available, repeated measurements by the nurse or patient should result in considerably less unnecessary monitoring, initiation, or changing of treatment. It is time to stop using high blood pressure readings documented by general practitioners to make treatment decisions.
What is already known on this topicProspective studies indicate that ambulatory blood pressure is a much better predictor of adverse outcome and response to treatment than readings made by a doctorPreliminary evidence suggests that measurements by doctors are likely to be higher than those made by nurses, technicians, or patientsNo study has compared all the available measures in a typical primary care setting with ambulatory blood pressure in patients with newly diagnosed and established hypertensionWhat this study addsThe white coat effect associated with measurements by doctors is not an artefact of research studies; it applies equally in primary care and for both initial diagnosis and assessment of controlIf ambulatory measurement is not possible, repeated measurement by a nurse or by the patient will result in much less unnecessary treatment or change in treatment for high blood pressure
PMCID: PMC117640  PMID: 12153923
11.  Effect on intra-arterial blood pressure of slow release metoprolol combined with placebo or chlorthalidone. 
Thirty patients with essential hypertension participated in a double blind crossover trial in which they were randomly allocated to treatment with either once daily slow release metoprolol (200 mg) with placebo or once daily slow release metoprolol (200 mg) with chlorthalidone (25 mg). Ambulatory intra-arterial blood pressure was recorded continuously for 24-48 hours before treatment and two months after each change in regimen. The response of blood pressure and pulse rate to a standard exercise protocol that included supine rest and tilt, isometric, and dynamic bicycle exercise was measured during the same recording periods. Both treatments appreciably reduced blood pressure and pulse rate; mean daytime intra-arterial blood pressure was reduced from 174/95 mm Hg to 158/85 mm Hg by metoprolol plus placebo and to 143/78 mm Hg by metoprolol plus chlorthalidone. This reduction with the combined treatment was significantly greater than with metoprolol and placebo (p systolic = 0.001, p diastolic = 0.004). Mean night time pressures were reduced from 148/78 mm Hg to 139/75 mm Hg by metoprolol plus placebo and to 116/61 mm Hg by metoprolol plus chlorthalidone. Again the reduction in blood pressure was significantly greater with combined treatment (p less than 0.001) than with metoprolol plus placebo. Once daily slow release metoprolol is effective in controlling blood pressure, but this effect is greatly enhanced by the addition of a diuretic.
PMCID: PMC1549066  PMID: 6412795
12.  Temporal stability of twenty-four-hour ambulatory hemodynamic bioimpedance measures in African American adolescents 
Blood Pressure Monitoring  2004;9(4):173-177.
Background
The reliability of ambulatory impedance cardiography has not been evaluated.
Objective
The purpose of this study was to determine the reproducibility of daytime and night-time ambulatory bioimpedance-derived measures of hemodynamic function in youth.
Methods
Thirty-five African American adolescents (ages 16.2 ± 1.4 years, 14 girls, 21 boys) with high normal systolic resting blood pressure (BP) were evaluated twice, separated by a 2-month interval. Measures were collected using the AIM-8-V3 Wearable Cardiac Performance Monitor (Bio-impedance Technology, Inc., Chapel Hill, North Carolina, USA) and the Spacelabs ambulatory BP monitor 90207 (Spacelabs Inc., Redmond, Washington, USA) from 0600 h to midnight every 20 min and from midnight to 0600 h every 30 min in the natural environment.
Results
There were no significantly different means (P > 0.15) between the two visits for daytime ambulatory heart rate (HR, r = 0.81), stroke volume (SV, r = 0.54), cardiac output (CO, r = 0.56), pre-ejection period (PEP, r = 0.59), left ventricular ejection time (LVET, r = 0.74), Heather Index (HI, r = 0.79), systolic BP (SBP, r = 0.79), diastolic BP (DBP, r = 0.66), mean arterial pressure (MAP, r = 0.65) and total peripheral resistance (TPR, r = 0.47). Overall means for night-time ambulatory HR (r = 0.76), SV (r = 0.49), CO (r = 0.45), LVET (r = 0.43), HI (r = 0.82), SBP (r = 0.65), DBP (r = 0.62), MAP (r = 0.63) and TPR (r = 0.20) were not significantly different between visits (P > 0.06). Mean differences (P < 0.01) were observed for PEP (r = 0.57).
Conclusions
The findings demonstrate that across 2 months in youth daytime and night-time ambulatory bioimpedance-derived measures of HR, HI, SBP, DBP and MAP are highly repeatable and SV, CO, PEP and LVET are moderately repeatable. This methodology should prove useful in cardiovascular research and clinical care.
PMCID: PMC3292177  PMID: 15311143
temporal stability; adolescent; African American; ambulatory; blood pressure; stroke volume; cardiac output; pre-ejection period; left ventricular ejection time; Heather Index; total peripheral resistance
13.  Prolonged blood pressure reduction by orally active renin inhibitor RO 42-5892 in essential hypertension. 
BMJ : British Medical Journal  1990;301(6745):205-210.
OBJECTIVE--To investigate the effects of a novel specific renin inhibitor, RO 42-5892, with high affinity for human renin (Ki = 0.5 x 10(-9) mol/l), on plasma renin activity and angiotensin II concentration and on 24 hour ambulatory blood pressure in essential hypertension. DESIGN--Exploratory study in which active treatment was preceded by placebo. SETTING--Inpatient unit of teaching hospital. PATIENTS--Nine men with uncomplicated essential hypertension who had a normal sodium intake. INTERVENTIONS--Two single intravenous doses of RO 42-5892 (100 and 1,000 micrograms/kg in 10 minutes) given to six patients and one single oral dose (600 mg) given to the three others as well as to three of the patients who also received the two intravenous doses. RESULTS--With both intravenous and oral doses renin activity fell in 10 minutes to undetectably low values, while angiotensin II concentration fell overall by 80-90% with intravenous dosing and by 30-40% after the oral dose. Angiotensin II concentration was back to baseline four hours after the low and six hours after the high intravenous dose and remained low for at least eight hours after the oral dose. Blood pressure fell rapidly both after low and high intravenous doses and after the oral dose and remained low for hours. With the high intravenous dose the daytime (0900-2230), night time (2300-0600), and next morning (0630-0830) systolic blood pressures were significantly (p less than 0.05) lowered by 12.5 (95% confidence interval 5.6 to 19.7), 12.2 (5.4 to 19.3), and 10.7 (3.2 to 18.5) mm Hg respectively, and daytime diastolic pressure was lowered by 9.3 (2.2 to 16.8) mmHg. With the oral dose daytime, night time, and next morning systolic blood pressures were lowered by 10.3 (5.5 to 15.4), 10.5 (4.2 to 17.2), and 9.7 (4.0 to 15.6) mm Hg, and daytime and night time diastolic pressures were lowered by 5.8 (0.9 to 11.0) and 6.0 (0.3-12) mm Hg respectively. CONCLUSIONS--The effect of the inhibitor on blood pressure was maintained over a longer period than its effect on angiotensin II. RO 42-5892 is orally active and has a prolonged antihypertensive effect in patients who did not have sodium depletion. This prolonged effect seems to be independent, at least in part, of the suppression of circulating angiotensin II.
PMCID: PMC1663555  PMID: 2203486
14.  Chronobiology of Arterial Hypertension in Hemodialysis Patients: Implications for Home Blood Pressure Monitoring 
Background
Hemodialysis patients have a steady increase in blood pressure (BP) over the 44-hour interdialytic interval when ambulatory BP monitoring is used. Home BP recording allows for longer period of monitoring between dialysis and may better define the chronobiology of arterial hypertension. This study sought to determine the optimal time to perform home BP monitoring in hemodialysis patients to improve the strength of prediction of 44-hour interdialytic ambulatory BP.
Study Design
Diagnostic test study
Setting and Participants
This is an ancillary analysis of patients participating in the dry-weight reduction in hypertensive hemodialysis patients (DRIP) trial.
Index test
Home BP measured three times a day for one week using a validated oscillometric monitor on 3 occasions at 4 week intervals after randomization. Home BP measured during the first third, second third and last third of time elapsed after dialysis as well as each third of dialysis was compared to the overall ambulatory BP.
Reference Tests
Interdialytic ambulatory BP measured on 3 occasions at 4 week intervals after randomization.
Results
Over the interdialytic interval, we found an increase in systolic ambulatory BP of 0.30 ± 0.36 mmHg/hr and an increase in systolic home BP of 0.40 ± 0.25 mmHg/hr. This relationship in home BP reached a plateau after approximately 48 hrs. A similar pattern was seen for diastolic home BP. Probing dry-weight steepened the slope of ambulatory BP but did not alter the time-dependent relationship of home BP. Home BP was on average higher (bias) by 14.1 (95% CI 12.0 to 16.2)/5.7 (95% CI 4.6 to 6.9) mmHg. The standard deviation of differences between methods (precision) was 4.6/2.8 mmHg. Measurement of BP during each third of the interdialytic interval gave the best precision as measured by model fit compared to ambulatory BP measurements.
Limitations
Our cohort was overrepresented by African American hemodialysis patients. Whether African American participants have a different pattern of BP response than non-African American participants in the interdialytic period is not known.
Conclusions
Our findings suggest that time elapsed after dialysis must to be considered in interpreting the home BP recordings in hemodialysis patients. Home BP measured in each third of the interdialytic interval is likely to yield the most reliable BP estimate.
doi:10.1053/j.ajkd.2009.03.018
PMCID: PMC2753716  PMID: 19515473
Home BP; ambulatory BP monitoring; hemodialysis; hypertension; chronobiology
15.  Acute Aerobic Exercise Reduces 24-H Ambulatory Blood Pressure Levels in Long-Term-Treated Hypertensive Patients 
Clinics (Sao Paulo, Brazil)  2008;63(6):753-758.
BACKGROUND
Even with anti-hypertensive therapy, it is difficult to maintain optimal systemic blood pressure values in hypertensive patients. Exercise may reduce blood pressure in untreated hypertensive, but its effect when combined with long-term anti-hypertensive therapy remains unclear. Our purpose was to evaluate the acute effects of a single session of aerobic exercise on the blood pressure of long-term-treated hypertensive patients.
METHODS
Fifty treated hypertensive patients (18/32 male/female; 46.5±8.2 years; Body mass index: 27.8±4.7 kg/m2) were monitored for 24 h with respect to ambulatory (A) blood pressure after an aerobic exercise session (post-exercise) and a control period (control) in random order. Aerobic exercise consisted of 40 minutes on a cycle-ergometer, with the mean exercise intensity at 60% of the patient’s reserve heart rate.
RESULTS
Post-exercise ambulatory blood pressure was reduced for 24 h systolic (126±8.6 vs. 123.1±8.7 mmHg, p=0.004) and diastolic blood pressure (81.9±8 vs. 79.8±8.5 mmHg, p=0.004), daytime diastolic blood pressure (85.5±8.5 vs. 83.9±8.8 mmHg, p=0.04), and nighttime S (116.8±9.9 vs. 112.5±9.2 mmHg, p<0.001) and diastolic blood pressure (73.5±8.8 vs. 70.1±8.4 mmHg, p<0.001). Post-exercise daytime systolic blood pressure also tended to be reduced (129.8±9.3 vs. 127.8±9.4 mmHg, p=0.06). These post-exercise decreases in ambulatory blood pressure increased the percentage of patients displaying normal 24h systolic blood pressure (58% vs. 76%, p=0.007), daytime systolic blood pressure (68% vs. 82%, p=0.02), and nighttime diastolic blood pressure (56% vs. 72%, p=0.02). Nighttime systolic blood pressure also tended to increase (58% vs. 80%, p=0.058).
CONCLUSION
A single bout of aerobic exercise reduced 24h ambulatory blood pressure levels in long-term-treated hypertensive patients and increased the percentage of patients reaching normal ambulatory blood pressure values. These effects suggest that aerobic exercise may have a potential role in blood pressure management of long-term-treated hypertensive.
doi:10.1590/S1807-59322008000600008
PMCID: PMC2664274  PMID: 19060996
Hypertension; Exercise; Blood Pressure; Treated Hypertension
16.  What is the optimal interval between successive home blood pressure readings using an automated oscillometric device? 
Journal of hypertension  2009;27(6):1172-1177.
Objectives
To clarify whether a shorter interval between three successive home blood pressure (HBP) readings (10 s vs. 1 min) taken twice a day gives a better prediction of the average 24-h BP and better patient compliance.
Design
We enrolled 56 patients from a hypertension clinic (mean age: 60 ±14 years; 54% female patients). The study consisted of three clinic visits, with two 4-week periods of self-monitoring of HBP between them, and a 24-h ambulatory BP monitoring at the second visit. Using a crossover design, with order randomized, the oscillometric HBP device (HEM-5001) could be programmed to take three consecutive readings at either 10-s or 1-min intervals, each of which was done for 4 weeks. Patients were asked to measure three HBP readings in the morning and evening. All the readings were stored in the memory of the monitors.
Results
The analyses were performed using the second–third HBP readings. The average systolic BP/diastolic BP for the 10-s and 1-min intervals at home were 136.1 ±15.8/77.5 ±9.5 and 133.2 ±15.5/76.9 ±9.3 mmHg (P = 0.001/0.19 for the differences in systolic BP and diastolic BP), respectively. The 1-min BP readings were significantly closer to the average of awake ambulatory BP (131 ±14/79 ±10 mmHg) than the 10-s interval readings. There was no significant difference in patients’ compliance in taking adequate numbers of readings at the different time intervals.
Conclusion
The 1-min interval between HBP readings gave a closer agreement with the daytime average BP than the 10-s interval.
PMCID: PMC2941726  PMID: 19462492
ambulatory BP monitoring; home BP; measurement interval; multiple BP measurements
17.  Impact of Breathing Awareness Meditation on Ambulatory Blood Pressure and Sodium Handling in Prehypertensive African American Adolescents 
Ethnicity & disease  2008;18(1):1-5.
Objectives
This study evaluated the impact of a breathing awareness meditation (BAM) program on ambulatory blood pressure and sodium handling in African American adolescents with high-normal systolic blood pressure (SBP) levels.
Design and Methods
Following three consecutive days of SBP screenings, 66 eligible ninth graders were randomly assigned by school to either BAM (n=20) or health education control (n=46) groups. The BAM group engaged in 10-minute BAM sessions at school and at home each day for three months. Teachers conducted sessions at school during health classes. Before and after the intervention, overnight urine samples were collected, and ambulatory SBP, diastolic blood pressure, and heart rate were recorded periodically for 24 hours.
Results
Significant changes before and after the intervention were observed between BAM and control groups for SBP during school hours (−4.7 vs .9 mm Hg, P<.05), SBP at night (−4.8 vs −.6 mm Hg, P<.01), and heart rate during school hours (−6.7 vs −2.3 bpm, P<.02), adjusted for their respective pre-intervention levels. The overnight urinary sodium excretion rate decreased in the BAM group but increased in the control group (−.3±4.9 vs 1.1±4.0 mEq/hour, P<.03).
Conclusions
These findings demonstrate the potential beneficial impact of BAM taught by school health teachers on blood pressure control in the natural environment in African American youth at risk for development of hypertension.
PMCID: PMC3216041  PMID: 18447091
Adolescents; Blood Pressure Monitoring; Meditation; Hypertension; Sodium Handling; African American; Clinical Trials
18.  Night time blood pressure dip 
World Journal of Cardiology  2015;7(7):373-376.
The advent of ambulatory blood pressure monitoring permitted examination of blood pressures during sleep and recognition of the associated circadian fall in pressure during this period. The fall in pressure, called the “dip”, is defined as the difference between daytime mean systolic pressure and nighttime mean systolic pressure expressed as a percentage of the day value. Ten percent to 20% is considered normal. Dips less than 10%, referred to as blunted or absent, have been considered as predicting an adverse cardiovascular event. This view and the broader concept that white coat hypertension itself is a forerunner of essential hypertension is disputable. This editorial questions whether mean arterial pressures over many hours accurately represent the systolic load, whether nighttime dipping varies from measure to measure or is a fixed phenomenon, whether the abrupt morning pressure rise is a risk factor or whether none of these issues are as important as the actual night time systolic blood pressure itself. The paper discusses the difference between medicated and nonmedicated white coat hypertensives in regard to the cardiovascular risk and suggests that further work is necessary to consider whether the quality and duration of sleep are important factors.
doi:10.4330/wjc.v7.i7.373
PMCID: PMC4513487  PMID: 26225196
Nighttime dip; Ambulatory blood pressure monitor; Blunting; Cardiovascular risk
19.  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
20.  The Impact of Blood Pressure Variability on Subclinical Ventricular, Renal and Vascular Dysfunction, in Patients with Hypertension and Diabetes 
Mædica  2013;8(2):129-136.
ABSTRACT
Background: Blood pressure variability (BPV) was proved as a cardiovascular risk factor. One of its mechanisms is related to arterial stiffness and ventriculo-arterial coupling; however its impact on subclinical cardiovascular dysfunction has not been evaluated yet.
Objectives: To assess the relationship between BPV on 24 hours, and subclinical left ventricle (LV), renal, and vascular dysfunction in diabetic and hypertensive patients. Material and methods: We studied 56 patients (57±9 years, 29 men) with mild-to-moderate hypertension and type 2 diabetes, no cardiovascular disease, normal ejection fraction and normal renal function. 24 hours ambulatory blood pressure monitoring (ABPM) was used to assess BPV, daytime (d) and night time (n), by: 1. mean (M); 2. standard deviation of mean (SD); 3. variance (Vr); 4. coefficient of variation (CV); 5. day/night variation: reverse dippers, non-dippers, dippers and extreme dippers; conventional and 2D speckle tracking echo to assess LV function; myocardial deformation was measured as global longitudinal strain (GLS). Endothelial (flow mediated dilation, FMD) and arterial function (intima media-thickness, IMT; pulse wave velocity, PWV), microalbuminuria were tested.
Outcomes: Daytime BPV correlates inversely with subclinical myocardial function evaluated through GLS. Daytime systolic BPV correlates positively with IMT (all rho > 0.30, all p < 0.05). Also, there is a significantly inverse correlation between mean BP and GLS. We found a direct correlation between mean BP, but not BPV, and microalbuminuria (all rho > - 0.30 and all p < 0.05). We found no correlation between BPV and FMD, PWV. There were no differences for GLS, microalbuminuria and FMD between dipper groups.
Conclusions: In diabetic patients with mild-to-moderate hypertension, increased daytime blood pressure variability correlates with subclinical left ventricular dysfunction and arterial function (IMT), while microalbuminuria correlates with elevated blood pressure, but not with blood pressure variability.
PMCID: PMC3865121  PMID: 24371476
blood pressure variability; ventricular dysfunction; diabetes; hypertension
21.  Home Blood Pressure Measurements for Managing Hypertension in Hemodialysis Patients 
American Journal of Nephrology  2009;30(2):126-134.
Home blood pressure (BP) monitoring serves as a practical method to detect changes in BP instead of ambulatory BP monitoring in hemodialysis patients. To evaluate the relationship of reduction in home BP compared to interdialytic ambulatory BP measurements we analyzed the data from the dry-weight reduction in hypertensive hemodialysis patients (DRIP) trial in which 100 patients had their dry weight probed based on clinical sign and symptoms and 50 patients served as controls. We measured home BP 3 times a day for 1 week using a validated oscillometric monitor on 3 occasions at 4-week intervals after randomization. Changes from baseline in home, predialysis BP and postdialysis BP were compared to interdialytic 44-hour ambulatory BP. Home and ambulatory BP monitoring was available in 141 of 150 (94%) patients. Predialysis systolic BP was not as sensitive as ambulatory BP in detecting change in BP with dry-weight reduction. Whereas postdialysis BP was capable of detecting an improvement in systolic BP in response to probing dry weight, by itself it does not provide evidence that change in postdialysis BP persists over the interdialytic period. Home BP reliably detected changes in ambulatory BP, albeit with less sensitivity at 4 weeks. However, at 4 and at 8 weeks, changes in home systolic BP were most strongly related to changes in interdialytic ambulatory systolic BP compared to predialysis and postdialysis BP. The reproducibility of BP measurements followed the order home > ambulatory >> predialysis > postdialysis. These data provide support for the use of home BP monitoring for the management of hypertension in hemodialysis patients.
doi:10.1159/000206698
PMCID: PMC2786027  PMID: 19246891
Home blood pressure monitoring; Ambulatory blood pressure monitoring; Hemodialysis; Hypertension
22.  Failure of psychological interventions to lower blood pressure: a randomized controlled trial 
Open Medicine  2009;3(2):e92-e100.
Background
Previous studies have suggested that psychological interventions may be effective in reducing blood pressure. Using rigorous methodology and 24-hour monitoring of ambulatory blood pressure, we compared 2 psychological interventions with treatment using a first-line antihypertensive drug in terms of their efficacy in lowering blood pressure in patients with mild primary hypertension.
Methods
In this prospective, open-label randomized controlled trial (RCT), 65 adult patients with mild, uncomplicated hypertension were randomly assigned to receive one of the following interventions for 12 weeks: (1) pharmacotherapy with hydrochlorothiazide 12.5 titrated to 25 mg/d ; (2) individualized behavioural psychotherapy, consisting of ten 1-hour sessions of stress reduction training with a psychologist; or (3) self-help psychotherapy, consisting of a 1.5-hour session with a psychologist and then daily sessions that involved reading a self-help manual and listening to an audiotape. The primary outcome measure was mean change in ambulatory blood pressure from baseline to week 12. Resting blood pressure readings were taken in the clinic, and adverse events were recorded.
Results
Monitoring of ambulatory blood pressure over 24 hours showed that hydrochlorothiazide therapy significantly reduced both systolic and diastolic blood pressure relative to baseline, and that this reduction was significantly greater than that achieved with either individualized behavioural psychotherapy or self-help psychotherapy (mean reduction [standard error; SE] −11.03 [2.53] / −6.06 [1.56] mm Hg v. −0.08 [2.38] / 0.29 [1.47] mm Hg v. −1.23 [2.83] / −0.71 [1.75] mm Hg, respectively; p = 0.01). Neither form of psychological therapy significantly lowered 24-hour ambulatory blood pressure relative to baseline.
Conclusion
For patients with primary elevated blood pressure, 2 psychological interventions did not lower 24-hour ambulatory blood pressure, whereas hydrochlorothiazide reduced blood pressure, as expected. The findings of this RCT represent an important addition to the evidence for health care practitioners and for patients seeking psychological interventions to reduce blood pressure.
PMCID: PMC2765772  PMID: 19946397
23.  Telemonitoring based service redesign for the management of uncontrolled hypertension: multicentre randomised controlled trial 
Objective To determine if an intervention consisting of telemonitoring and supervision by usual primary care clinicians of home self measured blood pressure and optional patient decision support leads to clinically important reductions in daytime systolic and diastolic ambulatory blood pressure in patients with uncontrolled blood pressure.
Design Multicentre randomised controlled trial.
Setting 20 primary care practices in south east Scotland.
Participants 401 people aged 29-95 years with uncontrolled blood pressure (mean daytime ambulatory measurement ≥135/85 mm Hg but ≤210/135 mm Hg).
Intervention Self measurement and transmission of blood pressure readings to a secure website for review by the attending nurse or doctor and participant, with optional automated patient decision support by text or email for six months.
Main outcome measures Blinded assessment of mean daytime systolic ambulatory blood pressure six months after randomisation.
Results 200 participants were randomised to the intervention and 201 to usual care; primary outcome data were available for 90% of participants (182 and 177, respectively). The mean difference in daytime systolic ambulatory blood pressure adjusted for baseline and minimisation factors between intervention and usual care was 4.3 mm Hg (95% confidence interval 2.0 to 6.5; P=0.0002) and for daytime diastolic ambulatory blood pressure was 2.3 mm Hg (0.9 to 3.6; P=0.001), with higher values in the usual care group. The intervention was associated with a mean increase of one general practitioner (95% confidence interval 0.5 to 1.6; P=0.0002) and 0.6 (0.1 to 1.0; P=0.01) practice nurse consultations during the course of the study.
Conclusions Supported self monitoring by telemonitoring is an effective method for achieving clinically important reductions in blood pressure in patients with uncontrolled hypertension in primary care settings. However, it was associated with increase in use of National Health Service resources. Further research is required to determine if the reduction in blood pressure is maintained in the longer term and if the intervention is cost effective.
Trial registration Current Controlled Trials ISRCTN72614272.
doi:10.1136/bmj.f3030
PMCID: PMC3663293  PMID: 23709583
24.  Telemonitoring based service redesign for the management of uncontrolled hypertension: multicentre randomised controlled trial 
The BMJ  2013;346:f3030.
Objective To determine if an intervention consisting of telemonitoring and supervision by usual primary care clinicians of home self measured blood pressure and optional patient decision support leads to clinically important reductions in daytime systolic and diastolic ambulatory blood pressure in patients with uncontrolled blood pressure.
Design Multicentre randomised controlled trial.
Setting 20 primary care practices in south east Scotland.
Participants 401 people aged 29-95 years with uncontrolled blood pressure (mean daytime ambulatory measurement ≥135/85 mm Hg but ≤210/135 mm Hg).
Intervention Self measurement and transmission of blood pressure readings to a secure website for review by the attending nurse or doctor and participant, with optional automated patient decision support by text or email for six months.
Main outcome measures Blinded assessment of mean daytime systolic ambulatory blood pressure six months after randomisation.
Results 200 participants were randomised to the intervention and 201 to usual care; primary outcome data were available for 90% of participants (182 and 177, respectively). The mean difference in daytime systolic ambulatory blood pressure adjusted for baseline and minimisation factors between intervention and usual care was 4.3 mm Hg (95% confidence interval 2.0 to 6.5; P=0.0002) and for daytime diastolic ambulatory blood pressure was 2.3 mm Hg (0.9 to 3.6; P=0.001), with higher values in the usual care group. The intervention was associated with a mean increase of one general practitioner (95% confidence interval 0.5 to 1.6; P=0.0002) and 0.6 (0.1 to 1.0; P=0.01) practice nurse consultations during the course of the study.
Conclusions Supported self monitoring by telemonitoring is an effective method for achieving clinically important reductions in blood pressure in patients with uncontrolled hypertension in primary care settings. However, it was associated with increase in use of National Health Service resources. Further research is required to determine if the reduction in blood pressure is maintained in the longer term and if the intervention is cost effective.
Trial registration Current Controlled Trials ISRCTN72614272.
doi:10.1136/bmj.f3030
PMCID: PMC3663293  PMID: 23709583
25.  Identification of sleep disruption and sleep disordered breathing from the systolic blood pressure profile. 
Thorax  1993;48(12):1242-1247.
BACKGROUND--Respiratory sleep studies are frequently performed to identify sleep disruption resulting from upper airway obstruction. Traditional polysomnographic studies may not detect brief recurrent sleep disruption and thus fail to recognise a significant problem when apnoea, hypopnoea, or arterial desaturation are not present. Arousal from sleep causes a transient blood pressure rise, and each inspiration causes a transient blood pressure fall. This study assesses whether these blood pressure changes are a useful indirect marker of disturbed sleep, obstructed sleep apnoea, and snoring related sleep disturbance. METHODS--Computer algorithms were developed to identify blood pressure falls caused by inspiration and rises related to arousal from 286 sleeping blood pressure samples of a consistent respiratory state drawn from 51 polysomnographic studies. From these samples, normal ranges for the number of arousal related systolic rises and the average size of the inspiratory falls were established. These were then applied prospectively to all night unedited blood pressure recordings from a further 20 subjects. RESULTS--The size of the inspiratory falls in blood pressure progressively increased from normal sleep, through snoring, to frank obstructive sleep apnoea. The 95th centile of normal was 12.5 mm Hg. The number of arousal related blood pressure rises also increased during obstructive sleep apnoea and periods of snoring with associated arousals, compared with normal undisturbed sleep, and all these periods of disturbed sleep included more than 30 such rises per hour. When these blood pressure features were examined in the 20 subjects studied prospectively, the six with a sleep related breathing disorder could all have been identified from their systolic blood pressure profile alone. CONCLUSIONS--The systolic blood pressure profile may be helpful in identifying patients with obstructive sleep apnoea, snoring with arousals, or other sleep disruption syndromes.
PMCID: PMC464983  PMID: 8303631

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