Type 2 diabetes is estimated to affect 20.6 million people in the United States and has particularly impacted African-American women, who are twice as likely to have the disease as non-Hispanic whites.

Recent studies indicated that the socioeconomic characteristics of a neighborhood can affect health status independent of socioeconomic status of an individual. Neighborhood environment influences diet and physical activity through the availability of grocery stores, recreational facilities and educational resources. In addition, neighborhoods vary with regard to sources of chronic stress (noise, violence and poverty).

This study looked at women who participated in the Black Women’s Health Study which has followed 59,000 black women from across the United States since 1995. The baseline questionnaire asked about a history of diabetes, and each follow-up questionnaire asked about a new diagnosis of diabetes. United States Census block group characteristics were used to measure neighborhood socioeconomic status.

During 12 years of follow-up of 46,382 participants aged 30-69 years, 3,833 new cases of type 2 diabetes occurred. The incidence of diabetes was the highest in women living in neighborhoods with the lowest socioeconomic status score after taking into account other risk factors for diabetes.

“Our findings indicate that the risk of type 2 diabetes for African-American women is influenced not just by individual characteristics, but by the characteristics of the neighborhoods in which they live,” said senior author Julie Palmer, Sc.D., a senior epidemiologist at the Slone Epidemiology Center and professor of epidemiology at Boston University School of Public Health. “Even women with the highest educational levels appeared to be affected by their neighborhood environment,” she added.

“Because many Africa-Americans live in disadvantaged neighborhoods regardless of their level of education, efforts to reduce the occurrence of diabetes need to include improving conditions in disadvantaged neighborhoods,” added study co-author Yvette Cozier, D.Sc., an epidemiologist at the Slone Epidemiology Center and an assistant professor of epidemiology at Boston University School of Public Health.