Comorbidities and impairments explaining the association between diabetes and lower extremity disability: The Women's Health and Aging Study.

OBJECTIVE To elucidate the role of diabetes-related impairments and comorbidities in the association between diabetes and physical disability, this study examined the association between diabetes and lower extremity function in a sample of disabled older women. RESEARCH DESIGN AND METHODS Cross-sectional analysis of 1,002 women (aged >or=65 years) enrolled in the Women's Health and Aging Study (one-third most disabled of the total community-dwelling population). Diabetes and other medical conditions were ascertained by standard criteria that used multiple sources of information. Functional status was assessed using self-reported and objective performance measures. RESULTS Women with diabetes were significantly more likely to have cardiovascular diseases, peripheral nerve dysfunction, visual impairment, obesity, and depression. After adjustment for age, women with diabetes had a greater prevalence of mobility disability (odds ratio [OR] 1.85, 95% CI 1.12-3.06), activities of daily living disability (1.61, 1.06-2.43), and severe walking limitation (2.34, 1.56-3.50), and their summary mobility performance score (0-12 scale based on balance, gait speed, chair stands) was 1.4 points lower than in nondiabetic women (P < 0.001). Peripheral artery disease, peripheral nerve dysfunction, and depression were the main individual contributing factors; however, none of these conditions alone fully explained the association between diabetes and disability. Conversely, only after adjusting for all potential mediators was the relationship between diabetes and disability reduced to a large degree. CONCLUSIONS Even among physically impaired older women, diabetes is associated with a major burden of disability. A wide range of impairments and comorbidities explains the diabetes-disability relationship, suggesting that the mechanism for such an association is multifactorial.