Neighborhood socioeconomic status and the incidence of hypertension in the black women's health study

Abstract

The incidence of hypertension in black women is two to three times that in white women. This discrepancy is largely unexplained by known risk factors such as family history, physical inactivity, smoking, and obesity. It has been proposed that chronic social and environmental stress, related to neighborhood of residence, may be associated with increased rates of hypertension in African Americans. We examined the relationship between neighborhood socioeconomic status (SES) and the incidence of hypertension using data from the Black Women's Health Study, a follow-up of 59,000 black women 21 to 69 years of age at entry in 1995. Block groups from the 2000 U.S. Census were used as proxies for neighborhood. A summary score for neighborhood SES was constructed from block group variables on education and wealth. Incident cases of hypertension were identified through follow-up postal questionnaires in 1997, 1999, and 2001. Clustered survival regression models were used to estimate incidence rate ratios (IRR). There were 3633 cases of self-reported hypertension among 183,207 person-years of observation from 1995 to 2001. The IRR for women living in low-SES neighborhoods relative to high-SES neighborhoods was 1.30 (95% confidence interval CI = 1.17–1.45) after adjusting for individual risk factors. The association was even stronger among younger women (IRR = 1.53; 95% CI = 1.18–1.97), women with low body mass index (IRR = 1.79; 95% CI = 1.41–2.29), the most educated women (IRR = 1.32; 95% CI = 1.12–1.54), and those who exercised regularly (IRR = 1.56; 95% CI = 1.09–2.23). Our findings indicate that neighborhood SES is strongly associated with the risk of hypertension, and that this is the case even among well-educated black women, thin black women, and black women who exercise regularly.