Education, glucose control, and mortality risks among U.S. older adults with diabetes.

Aims: Studies have shown that diabetes mellitus disproportionately afflicts persons of low socioeconomic status and that the burden of disease is greatest among the disadvantaged. However, our understanding of educational differences in the control of diabetes and its impact on survival is limited. This study investigated the associations among education, hemoglobin A1c (HbA1c), and subsequent mortality in adults with diabetes.

Methods: Prospective cohort data from the 2006, 2008, and 2010 Health and Retirement Study were linked with biomarker data for U.S. older adults with diabetes (n=3312). Weighted distributions were estimated for all subjects at baseline and by the American Diabetes Association's general guidelines for HbA1c control (<7.0% [53 mmol/mol] vs. ≥7.0% [53 mmol/mol]). Proportional hazard models were used to estimate educational differences in all-cause mortality by HbA1c level with sequential adjustments for contributing risk factors.

Results: Mortality risks associated with HbA1c≥7.0% [53 mmol/mol] were significantly greater in lower-educated adults than higher-educated adults (P<0.001). We found that the hazard ratios (HR) associated with HbA1c ≥7.0% [53 mmol/mol] were highest among low-educated adults (HR=2.18, 95% CI: 1.62, 2.94) and that a combination of socioeconomic, psychosocial, and behavioral factors accounted for most, but not all, of the associations.

Conclusions: Educational differences in HbA1c control have significant implications for mortality and efforts to reduce these disparities should involve more vigilant screening and monitoring of lower-educated adults with diabetes.