The contribution of baseline weight and weight gain to blood pressure change in African Americans: The Pitt County Study

PURPOSE: The positive association between obesity and blood pressure has been less consistent in African Americans than whites. This is especially true for African American men. This study investigated the sex-specific associations between baseline body mass index (BMI), weight change (kilograms), and five-year hypertension incidence and changes in blood pressure in a cohort of African Americans ages 25-50 years at baseline. METHODS: The Pitt County Study is a longitudinal investigation of anthropometric, psychosocial, and behavioral predictors of hypertension in African Americans. Data were obtained through household interviews and physical examinations in 1988 and 1993. RESULTS: Baseline BMI was positively and independently associated with changes in blood pressure after controlling for weight change and other covariates. When participants were stratified by sex-specific overweight vs, nonoverweight: status at baseline, weight gain was significantly associated with increases in blood pressure only among the initially nonoverweight. CONCLUSIONS: Baseline weight for all respondents, and weight gain among the nonoverweight at baseline, were independent predictors of blood pressure increases in this cohort of African Americans. (C) 1998 Elsevier Science Inc.