In a 1994–1998 cross-sectional study of a multiethnic sample of 2,211 men and women in San Diego, California, the authors estimated prevalence of the major manifestations of chronic venous disease: spider veins, varicose veins, trophic changes, and edema by visual inspection; superficial and deep functional disease (reflux or obstruction) by duplex ultrasonography; and venous thrombotic events based on history. Venous disease increased with age, and, compared with Hispanics, African Americans, and Asians, non-Hispanic Whites had more disease. Spider veins, varicose veins, superficial functional disease, and superficial thrombotic events were more common in women than men (odds ratio (OR) = 5.4, OR = 2.2, OR = 1.9, and OR = 1.9, respectively; p < 0.05), but trophic changes and deep functional disease were less common in women (OR = 0.7 for both; p < 0.05). Visible (varicose veins or trophic changes) and functional (superficial or deep) disease were closely linked; 92.0% of legs were concordant and 8.0% discordant. For legs evidencing both trophic changes and deep functional disease, the age-adjusted prevalences of edema, superficial events, and deep events were 48.2%, 11.3%, and 24.6%, respectively, compared with 1.7%, 0.6%, and 1.3% for legs visibly and functionally normal. However, visible disease did not invariably predict functional disease, or vice versa, and venous thrombotic events occurred in the absence of either.
cross-sectional studies; diagnostic imaging; ethnic groups; population; thrombosis; ultrasonics; veins
Although exertional leg pain is a hallmark of peripheral arterial disease (PAD) and can occur in persons without PAD, symptom variation has received inadequate attention.
Methods and Results
Three cohort studies were combined for cross-sectional analysis. The San Diego Claudication Questionnaire assessed exertional leg pain. PAD was defined as ankle brachial index (ABI) ≤0.90 or history of lower-extremity revascularization. Of 3658 subjects, 3629 were analyzed after exclusions. Of these, 24.1% had PAD in 1 or both legs. There was a stepwise decrease in average ABI, from no pain to pain on exertion and rest, noncalf pain, atypical calf pain, and classic claudication (P=0.002). When stratified by PAD, this trend was no longer significant. Legs with ABIs >0.90 and revascularization had pain distributions intermediate between that of normal legs (ABI, 1.00 to 1.39) and legs with ABIs ≤0.90. Compared with normal legs, legs with low-normal (0.91 to 0.99) and high-normal (≥1.40) ABIs had higher pain rates, suggesting borderline disease and vascular stiffness, respectively. Multivariable logistic regression models showed that ABI was a strong correlate of pain category throughout the ABI range. Independently of ABI, age, male sex, diabetes, smoking history, high body mass index, myocardial infarction, and previous revascularization were all significant correlates of exertional leg pain.
No category of exertional leg pain was sufficiently sensitive or specific for routine PAD diagnosis. Legs with low-normal and high-normal ABIs appeared to have ischemic leg pain; thus, a “normal ABI” is likely to range from 1.00 to 1.39. In addition to ABI, several risk variables were independent correlates of exertional leg pain.
claudication; epidemiology; exercise; peripheral vascular disease
To evaluate the predictive value of abdominal aortic calcium (AAC) for incident cardiovascular disease (CVD) independent of coronary artery calcium (CAC).
Approach and Results
We evaluated the association of AAC with CVD in 1974 men and women aged 45 to 84 years randomly selected from the Multi-Ethnic Study of Atherosclerosis participants who had complete AAC and CAC data from computed tomographic scans. AAC and CAC were each divided into following 3 percentile categories: 0 to 50th, 51st to 75th, and 76th to 100th. During a mean of 5.5 years of follow-up, there were 50 hard coronary heart disease events, 83 hard CVD events, 30 fatal CVD events, and 105 total deaths. In multivariable-adjusted Cox models including both AAC and CAC, comparing the fourth quartile with the ≤50th percentile, AAC and CAC were each significantly and independently predictive of hard coronary heart disease and hard CVD, with hazard ratios ranging from 2.4 to 4.4. For CVD mortality, the hazard ratio was highly significant for the fourth quartile of AAC, 5.9 (P=0.01), whereas the association for the fourth quartile of CAC (hazard ratio, 2.1) was not significant. For total mortality, the fourth quartile hazard ratio for AAC was 2.7 (P=0.001), and for CAC, it was 1.9, P=0.04. Area under the receiver operating characteristic curve analyses showed improvement for both AAC and CAC separately, although improvement was greater with CAC for hard coronary heart disease and hard CVD, and greater with AAC for CVD mortality and total mortality. Sensitivity analyses defining AAC and CAC as continuous variables mirrored these results.
AAC and CAC predicted hard coronary heart disease and hard CVD events independent of one another. Only AAC was independently related to CVD mortality, and AAC showed a stronger association than CAC with total mortality.
aortic diseases; calcium; cardiovascular diseases; diagnostic imaging; epidemiology
Coronary artery calcium (CAC), measured by computed tomography (CT), has strong predictive value for incident cardiovascular disease (CVD) events. The standard CAC score is the Agatston, which is weighted upward for greater calcium density. However, some data suggest increased plaque calcium density may be protective for CVD.
To determine the independent associations of CAC volume and CAC density with incident CVD events.
Design, Setting, and Participants
Multicenter, prospective observational MESA study (Multi-Ethnic Study of Atherosclerosis), conducted at 6 US field centers of 3398 men and women from 4 race/ethnicity groups; non-Hispanic white, African American, Hispanic, and Chinese. Participants were aged 45-84 years, free of known CVD at baseline, had CAC greater than 0 on their baseline CT, and were followed up through October 2010.
Main Outcomes and Measures
Incident coronary heart disease (CHD) and all CVD events
During a median of 7.6 years of follow-up, there were 175 CHD events and an additional 90 other CVD events for a total of 265 CVD events. With both lnCAC volume and CAC density scores in the same multivariable model, the lnCAC volume score showed an independent association with incident CHD, with a hazard ratio (HR) of 1.81 (95% CI, 1.47-2.23) per standard deviation (SD = 1.6) increase, absolute risk increase 6.1 per 1000 person-years, and for CVD an HR of 1.68 (95% CI, 1.42-1.98) per SD increase, absolute risk increase 7.9 per 1000 person-years. Conversely, the CAC density score showed an independent inverse association, with an HR of 0.73 (95% CI, 0.58-0.91) per SD (SD = 0.7) increase for CHD, absolute risk decrease 5.5 per 1000 person-years, and an HR of 0.71 (95% CI, 0.60-0.85) per SD increase for CVD, absolute risk decrease 8.2 per 1000 person years. Area under the receiver operating characteristic curve analyses showed significantly improved risk prediction with the addition of the density score to a model containing the volume score for both CHD and CVD. In the intermediate CVD risk group, the area under the curve for CVD increased from 0.53 (95% CI, 0.48-0.59) to 0.59 (95% CI, 0.54-0.64), P = .02.
Conclusions and Relevance
CAC volume was positively and independently associated with CHD and CVD risk. At any level of CAC volume, CAC density was inversely and significantly associated with CHD and CVD risk. The role of CAC density should be considered when evaluating current CAC scoring systems.
To determine in patients with peripheral arterial disease (PAD) whether novel biomarkers improve prediction of cardiovascular disease (CVD) mortality and total mortality.
Whether novel biomarkers improve risk prediction of mortality beyond standard CVD risk markers in PAD patients, and whether any such prediction differs with length of follow-up, remains controversial.
A cohort of 397 patients were referred to a vascular lab had PAD diagnosed by non-invasive testing. 58% also had coronary or cerebrovascular disease at baseline. Predictors of total, CVD, and non-CVD mortality were assessed with Cox proportional hazards models, and the incremental value of predictors were evaluated with both the C-statistic and the integrated discrimination improvement (IDI) index.
Total mortality was 11 % at 2 years of follow-up and 65 % at an average of 7 years of follow-up (maximum 11.4 years). At 2 years, hs-CRP was a strong and significant predictor of mortality, with a hazard ratio (HR) of 1.56 per standard deviation, p=.006. However, at full follow-up standard CVD risk markers were significant (age, sex, ankle-brachial index [ABI], other CVD, and hypertension), but hs-CRP no longer showed a significant relationship HR = 1.12, p = .11. None of the other biomarkers studied showed a significant independent association with mortality. Hs-CRP improved the C-statistic and the IDI beyond standard risk markers at 2 years, but not at full follow-up.
Hs-CRP was a strong predictor of short-term mortality in this cohort of PAD patients, while standard risk markers were better at predicting longer-term mortality.
biomarkers; peripheral arterial disease; cardiovascular diseases; risk prediction; mortality
There has been persistent controversy regarding possible favorable or adverse effects of statins or of cholesterol reduction on cognition, mood and behavior (including aggressive or violent behavior), muscle function, and quality of life. The UCSD Statin Study seeks to ascertain the beneficial or adverse effects of statin cholesterol-lowering drugs on a set of noncardiac endpoints, including cognition, behavior, and serotonin biochemistry. The study will enroll 1000 subjects (minimum 20% female) of mixed ethnicity from San Diego. Subjects must be age 20 and older, postmenopausal if female, without known cardiovascular disease or diabetes, and with LDL-cholesterol between 115 and 190 mg/dl. Subjects will be randomized to a double-blind, placebo-controlled trial with assignment 1/3, 1/3, 1/3 to placebo, simvastatin 20 mg, or pravastatin 40 mg (equipotent LDL-cholesterol-lowering doses for drug arms with simvastatin and pravastatin chosen to represent the extremes of the lipophilicity spectrum) for 6 months of treatment followed by 2 months postcessation follow-up. Primary outcomes are cognition (cognitive battery), irritability/aggression (behavior measure), and serotonin (gauged by whole blood serotonin), assessed as the difference between baseline and 6 months, judging combined statin groups vs. placebo. Secondary outcomes include mood (CES-D and Wakefield depression inventory), quality of life (SF-12V), sleep (Leeds sleep scale, modified), and secondary aggression measures (Conflict Tactics Scale; Overt Aggression Scale, Modified). Cardiovascular reactivity will be examined in a 10% subset. As additional secondary endpoints, primary and selected secondary outcomes will be assessed by statin assignment (lipophilic simvastatin vs. hydrophilic pravastatin). “Reversibility” of changes, if any, at 2 months postcessation will be determined. If effects (favorable or unfavorable) are identified, we will seek to ascertain whether there are baseline variables that predict who will be most susceptible to these favorable or adverse noncardiac effects (i.e., effect modification).
HMG-CoA reductase inhibitors; Statins; Serotonin; Risk–benefit; Cognition; Aggression
Some studies have suggested reductions in blood pressure (BP) with statin treatment, particularly in persons with hypertension. Randomized trial evidence is limited.
We performed a randomized, double-blind, placebo-controlled trial with equal allocation to simvastatin, 20 mg; pravastatin sodium, 40 mg; or placebo for 6 months. Nine hundred seventy-three men and women without known cardiovascular disease or diabetes mellitus, with low-density lipoprotein cholesterol screening levels of 115 to 190 mg/dL, had assessment of systolic and diastolic BP (SBP and DBP, respectively). Blood pressure values were compared for placebo vs statins by intention-to-treat (ITT) analysis. Additional analyses were performed that (1) were confined to subjects with neither high baseline BP (SBP >140 mm Hg or DBP >90 mm Hg) nor receiving BP medications, to exclude groups in whom BP medications or medication changes may have influenced results, and (2) separately evaluated simvastatin and pravastatin (vs placebo). The time course of BP changes after statin initiation and the effect of stopping statins on BP were examined.
Statins modestly but significantly reduced BP relative to placebo, by 2.2 mm Hg for SBP (P = .02) and 2.4 mm Hg for DBP (P<.001) in ITT analysis. Blood pressure reductions ranged from 2.4 to 2.8 mm Hg for both SBP and DBP with both simvastatin and pravastatin, in those subjects with full follow-up, and without potential for influence by BP medications (ie, neither receiving nor meriting BP medications).
Reductions in SBP and DBP occurred with hydrophilic and lipophilic statins and extended to normotensive subjects. These modest effects may contribute to the reduced risk of stroke and cardiovascular events reported on statins.
clinicaltrials.gov Identifier: NCT00330980
Molecular and cell biology studies have demonstrated an association between bone and arterial wall disease, but the significance of a population-level association is less clear and potentially confounded by inability to account for shared risk factors.
To test population-level associations between atherosclerosis types and bone integrity.
Main Outcome Measures
Volumetric trabecular lumbar bone mineral density (vBMD), ankle-brachial index (ABI), intima-media thickness of the common carotid (CCA-IMT) and internal carotid (ICA-IMT) arteries, and carotid plaque echogenicity.
Design, Setting and Participants
A random subset of participants from the Multi-Ethnic Study of Atherosclerosis (MESA) assessed between 2002 and 2005.
904 post-menopausal female (62.4 years; 62% non-white; 12% ABI<1; 17% CCA-IMT>1mm; 33% ICA-IMT>1mm) and 929 male (61.4 years; 58% non-white; 6% ABI<1; 25% CCA-IMT>1mm; 40% ICA-IMT>1mm) were included. In serial, sex-specific regression models adjusting for age, ethnicity, body mass index, dyslipidemia, hypertension, smoking, alcohol consumption, diabetes, homocysteine, interleukin-6, sex hormones, and renal function, lower vBMD was associated with lower ABI in men (p for trend <0.01) and greater ICA-IMT in men (p for trend <0.02). CCA-IMT was not associated with vBMD in men or women. Carotid plaque echogenicity was independently associated with lower vBMD in both men (trend p=0.01) and women (trend p<0.04). In all models, adjustment did not materially affect results.
Lower vBMD is independently associated with structural and functional measures of atherosclerosis in men and with more advanced and calcified carotid atherosclerotic plaques in both sexes.
Detrimental effects of lean muscle loss have been hypothesized to explain J-shaped relationships of body mass index (BMI) with cardiovascular disease (CVD), yet associations of muscle mass with CVD are largely unknown. We hypothesized that low abdominal lean muscle area would be associated with greater calcified atherosclerosis, independent of other CVD risk factors.
We investigated 1020 participants from the Multi-Ethnic Study of Atherosclerosis who were free of clinical CVD. Computed tomography (CT) scans at the 4th and 5th lumbar disk space were used to estimate abdominal lean muscle area. Chest and abdominal CT scans were used to assess coronary artery calcification(CAC), thoracic aortic calcification (TAC), and abdominal aortic calcification (AAC).
The mean age was 64±10 years, 48% were female, and mean BMI was 28±5 kg/m2. In models adjusted for demographics, physical activity, caloric intake, and traditional CVD risk factors, there was no inverse association of abdominal muscle mass with CAC(Prevalence Ratio [PR] 1.02 [95% CI 0.95,1.10]), TAC (PR 1.13 [95%CI 0.92, 1.39]) or AAC (PR 0.99 [95%CI 0.94, 1.04]) prevalence. Similarly, there was no significant inverse relationship between abdominal lean muscle area and CAC, TAC, and AAC severity.
In community-living individuals without clinical CVD, greater abdominal lean muscle area is not associated with less calcified atherosclerosis.
Cardiovascular Disease; atherosclerosis; lean muscle
Functional impairment, functional decline, and mobility loss are major public health problems in people with lower extremity peripheral artery disease (PAD). Few medical therapies significantly improve walking performance in PAD. We describe methods for the PROgenitor cell release Plus Exercise to improve functionaL performance in PAD (PROPEL) Study, a randomized controlled clinical trial designed to determine whether granulocyte-macrophage colony stimulating factor (GM-CSF) combined with supervised treadmill walking exercise improves six-minute walk distance more than GM-CSF alone, more than supervised treadmill exercise alone, and more than placebo plus attention control in participants with PAD, respectively. PROPEL Study participants are randomized to one of four arms in a 2 by 2 factorial design. The four study arms are GM-CSF plus supervised treadmill exercise, GM-CSF plus attention control, placebo plus supervised exercise therapy, or placebo plus attention control. The primary outcome is change in six-minute walk distance at 12-week follow-up. Secondary outcomes include change in brachial artery flow-mediated dilation (FMD), change in maximal treadmill walking time, and change in circulating CD34+ cells at 12-week follow-up. Outcomes are also measured at six-week and six-month follow-up. Results of the PROPEL Study will have important implications for understanding mechanisms of improving walking performance and preventing mobility loss in the large and growing number of men and women with PAD.
The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occurred since the Millennium Declaration.
To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010–13) of incidence, drug resistance, and coverage of insecticide-treated bednets.
Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990.
Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS’s estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action.
Bill & Melinda Gates Foundation.
Higher urine albumin-creatinine ratio (ACR) is associated with cardiovascular disease (CVD) events, an association that is stronger than that between spot urine albumin on its own and CVD. Urine creatinine is correlated with muscle mass, and low muscle mass is also associated with CVD. Whether low urine creatinine in the denominator of the ACR contributes to the association of ACR with CVD is uncertain.
Prospective cohort study.
Setting & Participants
6,770 community-living individuals without CVD.
Spot urine albumin, the reciprocal of the urine creatinine concentration (1/UCr), and ACR.
Incident CVD events.
During a mean of 7.1 years’ follow-up, 281 CVD events occurred. Geometric means for spot urine creatinine, urine albumin and ACR were 95 ± 2 (SD) mg/dl, 0.7 ± 3.7 mg/dl and 7.0 ± 3.1 mg/g. Adjusted HRs per 2-fold higher increment in each urinary measures with CVD events were similar (1/UCr: 1.07 [95% CI, 0.94-1.22]; urine albumin: 1.08 [95% CI, 1.01-1.14]; and ACR: 1.11 [95% CI, 1.04-1.18]). Urine creatinine was lower in older, female, and low weight individuals. ACR ≥10 mg/g was more strongly associated with CVD events in individuals with low weight (HR for lowest vs. highest tertile: 4.34 vs. 1.97; p for interaction=0.006). Low weight also modified the association of urine albumin with CVD (p for interaction=0.06), but 1/urine creatinine did not (p for interaction=0.9).
We lacked 24-hour urine data.
While ACR is more strongly associated with CVD events among persons with low body weight, this association is not driven by differences in spot urine creatinine. Overall, the associations of ACR with CVD events appear to be driven primarily by urine albumin and less by urine creatinine.
Both coronary artery calcification (CAC) and the ankle brachial index (ABI) are measures of subclinical atherosclerotic disease. The influence of physical activity on the longitudinal change in these measures remains unclear. To assess this we examined the association between these measures and self-reported physical activity in the Multi-Ethnic Study of Atherosclerosis (MESA).
At baseline, the MESA participants were free of clinically evident cardiovascular disease. We included all participants with an ABI between 0.90 and 1.40 (n=5656). Predictor variables were based on self-reported measures with physical activity being assessed using the Typical Week Physical Activity Survey from which metabolic equivalent-minutes/week of activity were calculated. We focused on physical activity intensity, intentional exercise, sedentary behavior, and conditioning. Incident peripheral artery disease (PAD) was defined as the progression of ABI to values below 0.90 (given the baseline range of 0.90 to 1.40). Incident CAC was defined as a CAC score >0 Agatston units upon follow up with a baseline score of 0 Agatston units.
Mean age was 61 years, 53% were female, and mean body mass index was 28 kg/m2. After adjusting for traditional cardiovascular risk factors and socioeconomic factors, intentional exercise was protective for incident peripheral artery disease (Relative Risk (RR)= 0.85, 95% Confidence Interval (CI): 0.74 to 0.98). After adjusting for traditional cardiovascular risk factors and socioeconomic factors, there was a significant association between vigorous PA and incident CAC (RR=0.97, 95% CI: 0.94 to 1.00). There was also a significant association between sedentary behavior and increased amount of CAC among participants with CAC at baseline (Δlog(Agatston Units +25)=0.027, 95% CI 0.002, 0.052).
These data suggest that there is an association between physical activity/sedentary behavior and the progression of two different measures of subclinical atherosclerotic disease.
Ankle Brachial Index; Coronary Artery Calcification; Physical Activity; Epidemiology; Prospective Cohort Study
Increasing adiposity increases the risk for left ventricular hypertrophy. Adipokines are hormone-like substances from adipose tissue that influence several metabolic pathways relevant to LV hypertrophy. Data was from participants enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent magnetic resonance imaging of the heart and who also had fasting venous blood assayed for 4 distinct adipokines (adiponectin, leptin, tumor necrosis factor – alpha and resistin). 1,464 MESA participants had complete data. The mean age was 61.5 years, the mean body mass index was 27.6 kg/m2 and 49% were female. With adjustment for age, sex, race, height and weight, multivariable linear regression modeling revealed that a 1-SD increment in leptin was significantly associated with smaller LV mass (ß: −4.66 % predicted, p-value: < 0.01), LV volume (−5.87 % predicted, < 0.01), stroke volume (−3.23 ml, p < 0.01) and cardiac output (−120 mL/min, p = 0.01) as well as a lower odds ratio for the presence of LV hypertrophy (OR: 0.65, p < 0.01), but a higher ejection fraction (0.44%, p = 0.05). Additional adjustment for the traditional cardiovascular disease (CVD) risk factors, insulin resistance, physical activity, education, income, inflammatory biomarkers, other selected adipokines and pericardial fat did not materially change the magnitude or significance of the associations. The associations between the other adipokines and LV structure and function were inconsistent and largely non-significant. In conclusion, the results indicate that higher levels of leptin are associated with more favorable values of several measures of LV structure and function.
leptin; left ventricle; hypertrophy; mass
Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) is associated with clinically overt heart failure (HF). However, whether it provides additive prognostic information for incident HF beyond traditional risk factors and left ventricular (LV) mass index among multi-ethnic asymptomatic individuals has not yet been determined. We studied the associations of plasma NT-proBNP and magnetic resonance imaging defined LV mass index with incident HF in an asymptomatic multi-ethnic population.
Methods and Results
A total of 5597 multi-ethnic participants without clinically apparent cardiovascular disease underwent baseline measurement of NT-proBNP and were followed for 5.5±1.1 years. Among them, 4163 also underwent baseline cardiac magnetic resonance imaging. During follow-up, 111 participants experienced incident HF. Higher NT-proBNP was significantly associated with incident HF, independent of baseline age, sex, ethnicity, systolic blood pressure, diabetes mellitus, smoking, estimated glomerular filtration rate, medications (anti-hypertensive and statin), LV mass index, and interim myocardial infarction (hazard ratio: 1.95 per 1U log NT-proBNP increment, 95% CI 1.54–2.46, P<0.001). This relationship held among different ethnic groups, non-Hispanic whites, African-Americans, and Hispanics. Most importantly, NT-proBNP provided additive prognostic value beyond both traditional risk factors and LV mass index for predicting incident HF (integrated discrimination index=0.046, P<0.001; net reclassification index; 6-year risk probability categorized by <3%, 3–10%, >10% =0.175, P=0.019; category-less net reclassification index=0.561, P<0.001).
Plasma NT-proBNP provides incremental prognostic information beyond traditional risk factors and the magnetic resonance imaging-determined LV mass index for incident symptomatic HF in an asymptomatic multi-ethnic population.
Clinical Trial Registration
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005487.
N-terminal pro-B-type natriuretic peptide; heart failure; left ventricular mass
In this study, the authors determined the prevalence and extent of cardiovascular disease (CVD) risk factors and subclinical CVD in four US Hispanic subgroups, as well as associations between the CVD risk factors and subclinical CVD in these groups. Participants were 1,437 Hispanic men and women enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000–2002. Fifty-six percent were Mexican-American, 12% were Dominican-American, 14% were Puerto Rican-American, and 18% were Other Hispanic-American. All participants underwent clinical examinations for coronary artery calcium, thoracic aortic calcium, carotid intimal-medial thickness, ankle-brachial index, left ventricular mass, and left ventricular size. Mexican Americans had the highest levels of coronary artery calcium, thoracic aortic calcium, and carotid intimal-medial thickness, while Puerto Rican Americans had the highest prevalence of an ankle-brachial index less than 1.0 and levels of left ventricular mass. The magnitudes of the associations between coronary artery calcium and age, sex, and body mass index were similar across all Hispanic subgroups. However, there were differences in the magnitude and significance of the associations between coronary artery calcium and hypertension, hypercholesterolemia, and cigarette smoking among the different Hispanic subgroups. This finding was also present for the other subclinical CVD measures. These results suggest a differential relationship between risk factors and either prevalence or extent of subclinical disease by Hispanic subgroup.
atherosclerosis; cardiovascular diseases; ethnic groups; Hispanic Americans; risk factors
We tested whether the association between bone mineral density (BMD) and coronary artery calcification (CAC) varies according to dyslipidemia in community-living individuals. Between 2002 and 2005, 305 women and 631 men (mean age of 64 years) and naïve to lipid-modifying medications and estrogen use were assessed for spine BMD, CAC, and total (TC), HDL- and LDL-cholesterol and triglycerides.
Random sample of participants from the Multi-Ethnic Study of Atherosclerosis (MESA) without clinical cardiovascular disease.
Spine BMD at the L3 vertebrate by computer tomography (CT).
CAC prevalence by CT.
Total cholesterol to HDL ratio (TC:HDL) ≥ 5.0.
The association of BMD with CAC differed in women with TC:HDL < 5.0 vs. higher (p-interaction =0.01). In age and race adjusted models, among women with TC:HDL < 5.0, each SD (43.4 mg/cc) greater BMD was associated with a 25% lower prevalence of CAC (Prevalence Ratio [PR] 0.75, 95% confidence interval [CI] 0.63–0.89), whereas among women with higher TC:HDL, higher BMD was not significantly associated with CAC (PR 1.22, 95% CI 0.82–1.82). Results were similar using other definitions of hyperlipidemia. In contrast, no consistent association was observed between BMD and CAC in men irrespective of the TC:HDL ratio (p interaction 0.54).
The inverse association of BMD with CAC is stronger in women without dyslipidemia. These data argue against the hypothesis that dyslipidemia is the key factor responsible for the inverse association of BMD with atherosclerosis.
Obesity is a risk factor for venous disease. We tested the associations between adipokines and the presence and severity of venous disease.
Participants for this analysis were drawn from a cohort of 2,408 employees and retirees of a university in San Diego who were examined for venous disease using duplex ultrasonography. From this cohort, a case-control study sample of all 352 subjects with venous disease and 352 age-, sex- and race-matched subjects without venous disease were included in this analysis. All subjects completed health history questionnaires, had a physical examination with anthropometric measurements and venous blood analyzed for adipokines.
After adjustment for age, sex and race, those with venous disease had significantly higher levels of body mass index (BMI), leptin and interleukin-6. Levels of resistin and tumor necrosis factor-alpha were also higher but of borderline significance (0.05 < p < 0.10). Compared to the lowest tertile and with adjustment for age, sex, race and BMI, the 2nd and 3rd tertiles of resistin (Odds Ratios: 1.9 & 1.7 respectively), leptin (1.7 & 1.7) and tumor necrosis factor-alpha (1.4 & 1.7) were associated with increasing severity of venous disease. Conversely, a 5 kg/m2 increment in BMI was associated with an increased odds (1.5) for venous disease, which was independent of the adipokines included in this study.
Both obesity and adipokines are significantly associated with venous disease. These associations appear to be independent of each other suggesting potentially different pathways to venous disease.
Using self-report of race/ethnicity, African Americans consistently have a higher prevalence of peripheral artery disease (PAD) compared to other ethnic groups. We aimed to determine the associations between estimated genetic admixture and PAD among African and Hispanic Americans. We studied the association between genetic ancestry and PAD among 1417 African and Hispanic American participants in the Multi-Ethnic Study of Atherosclerosis who were genotyped for ancestry informative markers (AIMs). PAD was defined as an ankle–brachial index (ABI) < 0.90. The overall prevalence of PAD among the 712 self-identified African American subjects was 15.2% and 4.6% among the 705 self-identified Hispanic Americans. A one standard deviation increment in European ancestry was associated with non-significant reductions in the odds for PAD among African (OR: 0.96 [95% CI: 0.78–1.18]) and Hispanic Americans (0.84 [0.58–1.23]), while the same increment in Native American ancestry was significantly associated with a lower odds of PAD in Hispanic Americans (0.56 [0.36–0.96]). Adjustment for demographic variables, field center, cardiovascular disease (CVD) risk factors and inflammatory markers strengthened the odds for European ancestry among African (0.85 [0.66–1.10]) and Hispanic Americans (0.68 [0.41–1.11]). The magnitude of the association for Native American ancestry among Hispanic Americans did not materially change (0.56 [0.29–1.09]). In conclusion, a higher percent Native American ancestry in Hispanics is associated with a lower odds of PAD while in both Hispanics and African Americans, greater European ancestry does not appear to be associated with lower odds for PAD.
epidemiology; genetics; peripheral artery disease
We studied associations of MRI-measured SFA occlusions with functional performance, leg symptoms, and collateral vessel number in PAD. We studied associations of collateral vessel number with functional performance in PAD.
Associations of magnetic resonance imaging (MRI)-detected superficial femoral artery (SFA) occlusion and collateral vessel number with functional performance among individuals with peripheral artery disease (PAD) have not been reported.
457 participants with an ankle brachial index (ABI) < 1.00 had MRI measurement of the proximal SFA with twelve consecutive 2.5 millimeter cross-sectional images. An occluded SFA was defined as an SFA in which at least one segment was occluded. A non-occluded SFA was defined as absence of any occluded slices. Collateral vessels were visualized with magnetic resonance angiography (MRA). Lower extremity functional performance was measured with the six-minute walk, four-meter walking velocity at usual and fastest pace, and the short physical performance battery (SPPB) (0-12 scale, 12=best).
Adjusting for age, sex, race, comorbidities, and other confounders, the presence of an SFA occlusion was associated with poorer six-minute walk performance (1,031 vs. 1,169 feet, P=0.006), slower fast-paced walking velocity (1.15 vs. 1.22 meters/second, P =0.042), and lower SPPB score (9.07 vs. 9.75, P=0.038) compared to the absence of an SFA occlusion. More numerous collateral vessels were associated with better six-minute walk performance (0-3 collaterals-1,064 feet, 4-7 collaterals-1,165 feet, ≥ 8 collaterals-1,246 feet, P trend=0.007), faster usual-paced walking speed (0-3 collaterals-0.84 meters/second, 4-7 collaterals-0.88 meters/second, ≥ 8 collaterals-0.91 meters/second, P trend=0.029), and faster rapid-paced walking speed (0-3 collaterals-1.17 meters/second, 4-7 collaterals-1.22 meters/second, ≥ 8 collaterals-1.29 meters/second, P trend=0.002), adjusting for age, sex, race, comorbidities, ABI, and other confounders.
Among PAD participants, MRI-visualized occlusions in the proximal SFA are associated with poorer functional performance, while more numerous collaterals are associated with better functional performance.
Clinical Trial ID
atherosclerotic plaque; intermittent claudication; peripheral arterial disease; physical functioning
We studied whether a 6‐month group‐mediated cognitive behavioral (GMCB) intervention for peripheral artery disease (PAD) participants, which promoted home‐based walking exercise, improved 6‐minute walk and other outcomes at 12‐month follow‐up, 6 months after completing the intervention, compared to a control group.
Methods and Results
We randomized PAD participants to a GMCB intervention or a control group. During phase I (months 1 to 6), the intervention used group support and self‐regulatory skills during weekly on‐site meetings to help participants adhere to home‐based exercise. The control group received weekly on‐site lectures on topics unrelated to exercise. Primary outcomes were measured at the end of phase I. During phase II (months 7 to 12), each group received telephone contact. Compared to controls, participants randomized to the intervention increased their 6‐minute walk distance from baseline to 12‐month follow‐up, (from 355.4 to 381.9 m in the intervention versus 353.1 to 345.6 m in the control group; mean difference=+34.1 m; 95% confidence interval [CI]=+14.6, +53.5; P<0.001) and their Walking Impairment Questionnaire (WIQ) speed score (from 36.1 to 46.5 in the intervention group versus 34.9 to 36.5 in the control group; mean difference =+8.8; 95% CI=+1.6, +16.1; P=0.018). Change in the WIQ distance score was not different between the 2 groups at 12‐month follow‐up (P=0.139).
A weekly on‐site GMCB intervention that promoted home‐based walking exercise intervention for people with PAD demonstrated continued benefit at 12‐month follow‐up, 6 months after the GMCB intervention was completed.
Clinical Trial Registration
URL: ClinicalTrials.gov. Unique identifier: NCT00693940.
behavior change; exercise; mobility; peripheral artery disease; physical functioning
We determined whether more adverse calf muscle characteristics and poorer peripheral nerve function were associated with impairments in self-perceived physical functioning and walking ability in persons with lower extremity peripheral arterial disease (PAD). Participants included 462 persons with PAD; measures included the ankle-brachial index (ABI), medical history, electrophysiologic characteristics of nerves, and computed tomography of calf muscle. Self-perceived physical functioning and walking ability were assessed using the 36-Item Short Form Health Survey (SF-36) and the Walking Impairment Questionnaire (WIQ). Results were adjusted for age, sex, race, ABI, body-mass index, comorbidities, and other confounders. Lower calf muscle area was associated with a poorer SF-36 physical function (PF) score (overall p trend<0.001, 33.76 PF score for the lowest quartile vs. 59.74 for the highest, pair wise p<0.001) and a poorer WIQ walking distance score (p trend=0.001, 29.71 WIQ score for the lowest quartile vs. 48.43 for the highest, pair wise p<0.001). Higher calf muscle percent fat was associated with a poorer SF-36 PF score (p trend<0.001, 53.76 PF score for the lowest quartile vs. 40.28 for the highest, pair wise p=0.009). Slower peroneal nerve conduction velocity was associated with a poorer WIQ speed score (p trend=0.023, 30.49 WIQ score for the lowest quartile vs. 40.48 for the highest, pair wise p=0.031). In summary, adverse calf muscle characteristics and poorer peripheral nerve function are associated significantly and independently with impairments in self-perceived physical functioning and walking ability in PAD persons.
peripheral arterial disease; calf muscle characteristics; peripheral nerve function; quality of life
The purpose of this study was to examine the association of both a low and a high ankle-brachial index (ABI) with incident cardiovascular events in a multi-ethnic cohort.
Abnormal ankle-brachial indices (ABIs), both low and high, are associated with elevated cardiovascular disease (CVD) risk. However, it is unknown whether this association is consistent across different ethnic groups, and whether it is independent of both newer biomarkers and other measures of subclinical atherosclerotic CVD.
6647 non-Hispanic white, African-American, Hispanic, and Chinese men and women aged 45–84 years from free-living populations in six United States field centers and free of clinical CVD at baseline had extensive measures of traditional and newer biomarker risk factors, and measures of subclinical CVD, including the ABI. Incident CVD, defined as coronary disease, stroke, or other atherosclerotic CVD death, was determined over a mean follow-up of 5.3 years.
Both a low (<1.00) and a high (≥ 1.40) ABI were associated with incident CVD events. Gender- specific and ethnic-specific analyses showed consistent results. Hazard ratios were 1.77 (p<.001) for a low and 1.85 (p=.050) for a high ABI after adjustment for both traditional and newer biomarker CVD risk factors, and the ABI significantly improved risk discrimination. Further adjustment for coronary artery calcium score, common and internal carotid intimal medial thickness, and major ECG abnormalities only modestly attenuated these hazard ratios.
In this study both a low and a high ABI were associated with elevated CVD risk in persons free of known CVD, independent of standard and novel risk factors, and independent of other measures of subclinical CVD. Further research should address the cost-effectiveness of measuring the ABI in targeted population groups.
peripheral arterial disease; ankle-brachial index; cardiovascular events; risk factors; subclinical atherosclerosis
Patient bone mineral density (BMD) predicts the likelihood of osteoporotic fracture.
While substantial progress has been made toward elucidating the genetic determinants of
BMD, our understanding of the factors involved remains incomplete. Here, using a systems
genetics approach in the mouse, we predicted that bicaudal C homolog 1
(Bicc1), which encodes an RNA-binding protein, is responsible for a BMD
quantitative trait locus (QTL) located on murine chromosome 10. Consistent with this
prediction, mice heterozygous for a null allele of Bicc1 had low BMD. We
used a coexpression network–based approach to determine how Bicc1
influences BMD. Based on this analysis, we inferred that Bicc1 was
involved in osteoblast differentiation and that polycystic kidney disease 2
(Pkd2) was a downstream target of Bicc1. Knock down of
Bicc1 and Pkd2 impaired osteoblastogenesis, and
Bicc1 deficiency–dependent osteoblast defects were rescued by
Pkd2 overexpression. Last, in 2 human BMD genome-wide association
(GWAS) meta-analyses, we identified SNPs in BICC1 and
PKD2 that were associated with BMD. These results, in both mice and
humans, identify Bicc1 as a genetic determinant of osteoblastogenesis and
BMD and suggest that it does so by regulating Pkd2 transcript levels.