Abstract 435: Adiposity Increases Blood Pressure in Blacks More Than in Whites
Strong associations between adiposity and blood pressure (BP) have been observed consistently in most human populations. While obesity and hypertension are more prevalent in blacks, it is unclear whether adiposity affects BP differentially in blacks and whites and whether mechanisms by which adiposity exerts its influence are common across populations. The current study examined the effects of body mass index (BMI) on BP using longitudinally collected data from healthy black and white children. Using nonparametric regression techniques, we assessed the concurrent influences of age and BMI on BP. The analysis was based on 9113 observations from 1112 subjects (463 blacks and 649 whites; enrollment ages 4-17 years). To accommodate age and sex-related variations in BP and to compare BP in subjects of different ages, we modeled age and sex adjusted BP percentile values (BP%). The mean systolic BP% were 43% and 38% for blacks and whites respectively (p<0.0001); mean BMI% values were 71% and 60% for blacks and whites (p<0.0001). Model fitting results were presented in colored contour plots, which showed that at the same age and BMI level, black subjects tended to have higher BP%. (See Fig 1) The results were consistently observed for male and female subjects (data not shown). Blacks had significantly lower plasma renin activity than whites (PRA; 2.8 vs 3.4 ng/mL/h, p<0.0001), and in addition BMI was negatively associated with PRA in blacks (p=0.001). In conclusion, adiposity increases BP in blacks more than in whites. The lower PRA levels and negative BMI-PRA association observed in blacks suggest that the increase of adiposity effect may be related to expanded extracellular fluid volume.
- © 2012 by American Heart Association, Inc.