The Comorbid Influence of High Depressive Symptoms and Diabetes on Mortality and Disability in Mexican Americans Aged 75 and Above

OBJECTIVE: To examine the individual and combined effects of depression and diabetes on mortality and disability over 6 years among Mexican Americans aged ≥75. METHOD: The final sample included 1,785 participants from the Hispanic Established Population for the Epidemiological Study of the Elderly. Cox proportional hazards regression models were used to estimate the hazard ratios for incidence for mortality and disability according to diabetes and depressive symptoms. RESULTS: Diabetics were more likely to become activities of daily living (ADL) disabled Hazard Ratio (HR) = 1.44, 95% confidence interval [CI] = [1.18, 1.77]) and deceased (HR = 1.47, 95% CI = [1.24, 1.74]) compared with non-diabetics. Diabetics reporting high depressive symptomatology were more than two times as likely to become ADL disabled and deceased compared with diabetics not reporting high depressive symptoms. Participants with high depressive symptoms and taking insulin alone or both oral medications and insulin were at the greatest risk of disability (HR = 3.83, 95% CI = [1.66, 8.81]). CONCLUSION: Diabetes increases the risk of disability and mortality, especially among Mexican Americans with high depressive symptoms or who are taking insulin alone or both oral medications and insulin. Interventions that are able to reduce the prevalence of depression and diabetes are needed to limit the future burden of disability and mortality in this population.