Background High waist circumference (WC) (women: 88cm; men: 102cm) increases cardiovascular risk. Less is known about moderate WC (women: 80-88cm; men: 94-102cm). Therefore, we examined the association between moderate WC and hypertension prevalence, independent of body mass index (BMI).MethodsAmong 24,247 eligible adults 45-84 years old, when recruited from January 2003 to October 2007 in the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort, we examined hypertension prevalence (systolic blood pressure (BP) 140mmHg, or diastolic BP 90mmHg, or self-reported antihypertensive medication use) by WC before and after stratification by BMI (normal: 18.5-24.9; overweight: 25-29.9; obese class I: 30-34.9). Logistic regression adjusted associations between WC, BMI, and hypertension prevalence for age, race, sex, region, income, education, cigarette smoking, glomerular filtration rate, alcohol use, and physical activity.ResultsOverall, hypertension prevalence was 44% among those with low WC (n = 8,068), 55% with moderate WC (n = 6,488), and 66% with high WC (n = 9,691). After full adjustment, moderate WC was independently associated with hypertension prevalence among persons with normal BMI, (adjusted odds ratio (aOR), 1.49; 95% confidence interval (CI), 1.31-1.70), overweight BMI (aOR, 1.80; 95% CI, 1.64-1.98), and obese class I BMI (aOR, 2.28; 95%CI, 1.96-2.65) (referent: low WC-normal BMI). The moderate WC-hypertension association was observed in blacks and whites and in men and women.ConclusionModerate WC is associated with hypertension prevalence independent of BMI and several hypertension risk factors in middle-aged and older adults. © 2011 American Journal of Hypertension, Ltd.