Associations between depressive symptoms and incident ESRD in a diabetic cohort

Comorbid major depression is associated with adverse health outcomes in patients with diabetes, but little is known regarding its associations with long-term renal outcomes in this population. Furthermore, the impact of minor depression on renal outcomes is not known. This study evaluated associations between depressive symptoms and risk of incident ESRD in a diabetic cohort.

In this prospective, observational cohort study, 3886 ambulatory adults with diabetes were recruited from primary care clinics of a large health maintenance organization in the state of Washington. Demographics, laboratory data, depressive symptoms (based on the Patient Health Questionnaire-9), and patterns of diabetes self-care were collected. Participants were considered depressed if they had the required number of depressive symptoms (≥ 5 for major or 2-4 for minor depressive symptoms), including depressed mood or anhedonia, >50% of the time for ≥ 2 weeks and a Patient Health Questionnaire-9 score ≥ 10 for major and ≥ 5 for minor depressive symptoms. Risk of incident ESRD was estimated using Cox proportional hazards regression, with predialysis death as a competing risk.

During a median follow-up of 8.8 years, 87 patients (2.2%) developed ESRD. Major depressive symptoms were associated with a higher risk of incident ESRD (hazard ratio, 1.85; 95% confidence interval, 1.02 to 3.33) after adjusting for age, sex, race/ethnicity, marital status, education, smoking, body mass index, diabetes duration, hemoglobin A1c, baseline kidney function, microalbuminuria, hypertension, renin-angiotensin system blockers, and adherence to diabetes self-care. Minor depressive symptoms were not significantly associated with incident ESRD (hazard ratio, 1.08; 95% confidence interval, 0.52 to 2.25).

Major depressive symptoms, but not minor depressive symptoms, were associated with a higher risk of incident ESRD over 10 years. Additional studies are needed to determine whether treatment for depression can improve renal outcomes in patients with diabetes.