Socioeconomic Status and Incident Type 2 Diabetes Mellitus: Data from the Women's Health Study

OBJECTIVES: We prospectively examined whether socioeconomic status (SES) predicts incident type II diabetes (diabetes), a cardiovascular risk equivalent and burgeoning public health epidemic among women. METHODS: Participants include 23,992 women with Hb(A1c) levels <6% and no CVD or diabetes at baseline followed from February 1993 to March 2007. SES was measured by education and income while diabetes was self-reported. RESULTS: Over 12.3 years of follow-up, 1,262 women developed diabetes. In age and race adjusted models, the relative risk of diabetes decreased with increasing education (<2 years of nursing, 2 to <4 years of nursing, bachelor's degree, master's degree, and doctorate: 1.0, 0.7 95% Confidence Interval (CI), 0.6-0.8, 0.6 (95% CI, 0.5-0.7), 0.5 (95% CI, 0.4-0.6), 0.4 (95% CI, 0.3-0.5); p(trend)<0.001). Adjustment for traditional and non-traditional cardiovascular risk factors attenuated this relationship (education: p(trend) = 0.96). Similar associations were observed between income categories and diabetes. CONCLUSION: Advanced education and increasing income were both inversely associated with incident diabetes even in this relatively well-educated cohort. This relationship was largely explained by behavioral factors, particularly body mass index.