May 10, 2010

Social context may affect obesity disparities more than race

When analyzing obesity disparities among women, socioeconomic status and social context may be more important than race, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health’s Center for Health Disparities Solutions.

The authors examined race disparities in obesity among black and white women living in the same social context with similar income and compared these estimates to national data. Nationwide, black women were twice as likely to be obese when compared to white women. However, the researchers found that obesity rates were comparable in a sample of white and black women living in similar social and environmental conditions. The results are featured in the May issue of the Journal of Epidemiology and Community Health.

“In a national sample not accounting for race differences in social context, black women had twice the chance of being obese as compared to white women,” said lead author Sara Bleich, an assistant professor in the Bloomberg School’s Department of Health Policy and Management. “To date, efforts to explain the disparity in obesity prevalence have primarily focused on individual-level factors, and little research has focused on social context as a possible explanation. When we examined poor urban women exposed to the same environment, race disparities in obesity virtually disappeared.”

Bleich and colleagues from the Center for Health Disparities Solutions examined race disparities in obesity among black and white women living in the same social context with similar income in Baltimore. Using the data from the Exploring Health Disparities in Integrated Communities–Southwest Baltimore study, a cross-sectional face-to-face survey of adults ages 18 and older, researchers compared estimates to national data from the National Health Interview Survey to determine if the race disparity in obesity was attenuated among women living in the same social context. Obesity was calculated from self-reported height and body weight, and logistic regression was used to examine the association between race and obesity.

“Accurately accounting for social and environmental exposures is particularly important for the study of obesity disparities given the growing literature linking individual body weight to a host of environmental factors both positively and negatively associated with body mass index,” said Thomas LaVeist, senior author of the study and director of the Center for Health Disparities Solutions. “Developing policies that focus on modifying social aspects of the environment may reduce disparities in obesity among low-income women living in urban communities.”

The study was written by Bleich, Roland Thorpe, Hamidah Sharif-Harris, Ruth Fesahzion and LaVeist.

The research was supported by the National Center on Minority Health and Health Disparities of the National Institutes of Health, Pfizer, the National Heart Lung and Blood Institute and the Health Disparities Loan Repayment Program.