Blood pressure studies in black and white inner-city and suburban adolescents

Blood pressures and anthropometric and demographic variables were assessed in 536 students, ages 14–17 years, in integrated suburban and urban schools with comparison of blood pressures between black and white adolescents within and between suburban and urban schools. Of the 536 students, 339 were in a suburban school (237 white and 102 black), and of the 197 students in an urban school, 63 were white and 134 were black. Using multiple regression, explanatory variables significantly entering the equation for systolic blood pressure included sex, geographic area (urban higher), and left-arm circumference; significant explanatory variables in the equation for diastolic blood pressure included geographic area (urban higher), age, and left-arm circumference. These variables were consequently used in analysis of covariance as covariables (age and left-arm circumference), or as independent variables (sex and geographic area). After covariance adjustment for the explanatory variables above, differences in systolic and diastolic blood pressure between geographic areas remained significant (urban higher), while differences between races remained nonsignificant. After covariance adjustment, urban-suburban differences in both systolic and diastolic blood pressures were greater for blacks than whites, a significant race-geographic area interaction. Within geographic areas, there were no significant black-white systolic and diastolic blood pressure differences, save for higher pressures in suburban white females compared with suburban black females. Urban students of both races had higher blood pressures than their suburban counterparts. This finding suggests that shared environments for both races leads to shared blood pressures.