Abid R. Maqbool

The impact of body mass index on pulse pressure in obesity.

Objective Pulse pressure, a marker of arterial vascular properties, has been linked to cardiovascular diseases and complications. This study examined the impact of excess body mass and cardiovascular disease risk factors on pulse pressure (PP). Design Cross-sectional and prospective study. Methods Baseline data consist of 219 obese African Americans, with mean ± SD age of 46.8 ± 10.9 years enrolled in a diet and exercise program of weight reduction. A non-invasive monitoring device was used to acquire 24 hourly ambulatory blood pressures. Pulse pressure was calculated as the difference between the average 24-h systolic and diastolic blood pressure and studied as a continuous variable and according to quartiles. The cross-sectional association of pulse pressure with body mass index (BMI) was examined using multivariate linear regression and proportional odds models that controlled for cardiovascular disease risk factors. In addition, we examined prospectively, in 36 participants, the effect of weight loss on pulse pressure, using the Wilcoxon signed ranked test. Results At baseline, a 5 kg/m2 increase in BMI was independently associated with a 35% risk [relative risk (RR) = 1.35, confidence interval (CI) = 1.10–1.65, P < 0.01] in the general study population and 19% (RR = 1.19, CI = 1.07–1.56, P = 0.04) in obese normotensives for increasing PP by one quartile after adjustment for other significant variables. After 3 months of diet and exercise intervention, BMI decreased by an average of 10.6% (P < 0.01) and resulted in an 8.8% (P < 0.01) reduction in PP. Conclusions In the context of obesity, increasing BMI is independently associated with decreasing arterial compliance, as reflected in PP. This association highlights the potential value to cardiovascular health of any reduction in body weight in obese individuals.

Effect of diet and exercise on pulse pressure and cardiac function in morbid obesity : Analysis of 24-hour ambulatory blood pressure

Blood pressure is a major risk factor for cardiovascular events, although the role of pulse pressure, an independent predictor of arterial stiffness, has recently been emphasized. This study examines the baseline relationship between body mass index (BMI) and blood pressure indexes in 215 obese African Americans enrolled in a diet—exercise program. The subject population was 77% female, with a mean ± SD age of 46.7±10.7 years and a mean BMI of 42.5±7.5 kg/m2. In addition, the authors prospectively examined the effect of weight loss on cardiovascular parameters in a subset of 25 participants. The results show a closer significant correlation between pulse pressure and BMI (β=1.97 kgm−1; p=0.001) than between systolic blood pressure and BMI (β=1.58 kgm1; p=0.020). After 3 months of diet and exercise, average reductions were as follows: BMI, 4.2 kg/m2 (p<0.01); systolic blood pressure, 7.2 mm Hg (p<0.01); pulse pressure, 4.8 mm Hg (p<0.01); and cardiac output, 975 mL/min (p<0.01). Compliance index increased by 0.1 mL/mm Hg/m2 (p=0.03). The results highlight the potential value to cardiovascular health of a modest reduction in body weight in obese individuals.

The Relationship Between Flow-Mediated Dilatation of the Brachial Artery and Intima-Media Thickness of the Carotid Artery to Framingham Risk Scores in Older African Americans

The objective of this study was to investigate the relationship of flow‐mediated dilatation and intima‐media thickness (IMT) with coronary risk in African Americans (AAs). Endothelial dysfunction and IMT of carotid arteries are considered early steps in atherosclerotic disease process and have been used as surrogate markers of subclinical atherosclerosis. Data were collected on 106 AAs with a mean age of 64.0±6.6 years. Carotid artery IMT was measured with B‐mode ultrasonography, as was brachial artery diameter at rest, during reactive hyperemia, and after nitroglycerin. Percent change in flow‐mediated dilatation (%FMD) was defined as 100×(diameter during reactive hyperemia – resting diameter)/resting diameter. Percent change in nitroglycerin‐mediated dilatation (%NMD) was defined as 100×(diameter with nitroglycerin‐resting diameter)/resting diameter. The Framingham 10‐year risk score (FRS) was calculated for each patient using the National Cholesterol Education Program (NCEP) risk score calculator and participants were categorized into 3 groups with FRS as <10%, 10% to 20%, and >20%. Thirty‐eight participants had risk scores <10%, 26 had 10% to 20%, and 42 >20%. There was a significant inverse relation between %FMD and FRS (P<.0001) and between %NMD and FRS (P<.001). IMT was not statistically different among the risk groups. Endothelial dysfunction assessed by FMD significantly correlates inversely with FRS in AAs. FMD, an index of arterial compliance, appears to be a sensitive and reliable index of cardiovascular disease.

Nocturnal blood pressure nondipping in obese African-Americans.

ObjectivesNondipping pattern of circadian blood pressure (BP) is associated with increased cardiovascular morbidity and mortality; however, limited data are available among obese African–Americans. We, therefore, aimed to evaluate the pattern of circadian BP variation and to identify clinical conditions associated with nondipping in this population. MethodsA total of 211 obese African–Americans enrolled in a weight-reduction program underwent 24-h ambulatory BP monitoring. Nondipping was defined as a nocturnal BP reduction of less than 10%. ResultsSystolic BP (SBP) nondipping was present in 158 participants (74.9%) and diastolic BP (DBP) nondipping was present in 93 participants (44.1%). In multivariate logistic regression analyses, diabetes was associated with SBP nondipping (adjusted OR, 2.53; CI: 1.16–5.76; P=0.02), and increasing BMI (5 kg/m2) was associated with DBP nondipping (adjusted OR, 1.46; CI: 1.17–1.83; P=0.001). In linear regression analyses, BMI was positively correlated to office, 24-h, daytime, and night-time SBP (P=0.03, 0.01, 0.03, and 0.005, respectively) and office, 24-h, daytime, and night-time PP (P=0.01, P<0.001, 0.001, and P=0.003, respectively). ConclusionThis study demonstrated an excessively high prevalence of nondippers and independent associations between diabetes and SBP nondipping and between BMI and DBP nondipping in an obese African–American population.

Effects of a low-calorie, low-salt diet and treadmill exercise on atherosclerotic risk factors in obese African-American women *

C disease risk factors encompass a multitude of conditions; however, certain factors are clearly related to the risk of heart disease, atherosclerosis, hypertension, and stroke, each of which affects millions of Americans each year. Obesity, an independent, modifiable major risk factor for the development of cardiovascular disease, is a complex multifactorial chronic condition. An estimated 97 million adults in the USA are overweight or obese: body mass index (BMI) 25 kg/m. Overweight and obesity are especially evident in some minority groups and in those with lower income and less education. According to the National Health and Nutrition Examination Survey of 1998, the prevalence is highest in non-Hispanic black women (66%). Clinical trials have demonstrated the effectiveness of behavior modification in reducing body weight, blood pressure, serum lipids, and blood glucose level. However, few studies or clinical trials conducted thus far have focused on blacks. There is a need for comprehensive programs targeting African-American women that can have lasting impact on cardiovascular risk factors. This study, conducted at the Howard University General Clinical Research Center (the study center), recruited subjects from the community to demonstrate the feasibility of achieving the intended goal.