Diabetes Self-Care, Major Depression, and Chronic Kidney Disease in an Outpatient Diabetic Population

Abstract

Background/Aims: The associations between major depression and chronic kidney disease (CKD) in patients with diabetes are incompletely characterized. Depressed patients with diabetes are known to have worse diabetes self-care, but it is not known whether this mediates the association between depression and CKD in this population. Methods: We conducted a cross-sectional study of the associations between major depressive symptoms and CKD in the Pathways Study (n = 4,082), an observational cohort of ambulatory diabetic patients from a managed care setting. Depression status was ascertained using the Patient Health Questionnaire-9 (PHQ-9). Stepwise logistic regression models examined the associations between depression and impaired estimated glomerular filtration rate (<60 ml/min/1.73 m²) or microalbuminuria, after adjustment for demographics, CKD risk factors, and diabetes self-care variables. Results: Clinically significant depression symptoms (PHQ-9 ≥10) were associated with a greater risk of microalbuminuria after adjustment for demographic variables (OR 1.54, 95% CI 1.21-1.95) and traditional CKD risk factors (OR 1.36, 95% CI 1.04-1.77); this association persisted after additional adjustment for diabetes self-care (OR 1.34, 95% CI 1.02-1.75). Depression was not associated with impaired estimated glomerular filtration rate in any of the models. Conclusion: In this cohort of diabetic subjects, clinically significant depression symptoms were associated with microalbuminuria, which could not be entirely explained by differences in diabetes self-care.