OBJECTIVE It is not known if diabetic patients with depression have an increased risk of chronic kidney disease (CKD). We examined the association between depression and incident CKD, mortality, and incident cardiovascular events in U.S. veterans with diabetes mellitus (DM).
RESEARCH DESIGN AND METHODS Among a nationally representative prospective cohort of >3 million U.S. veterans with baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2, we identified 933,211 diabetic patients. DM was ascertained by an ICD-9-CM code for diabetes, an HbA1c >6.4%, or receiving antidiabetic medication during the inclusion period. Depression was defined by an ICD-9-CM code for depression or by antidepressant use during the inclusion period. Incident CKD was defined as two eGFR levels <60 mL/min/1.73 m2 separated by ≥90 days and a >25% decline in baseline eGFR. The associations between depression and outcomes were assessed using Cox proportional regression.
RESULTS Depression was present in 340,806 patients at enrollment. Depressed patients were younger (61 ± 11 vs. 65 ± 11 years), had higher eGFR (84 ± 15 vs. 81 ± 14 mL/min/1.73 m2), but had more comorbidities. Incident CKD developed in 180,343 patients. Depression was associated with 20% higher risk of incident CKD (adjusted hazard ratio [aHR] and 95% CI: 1.20 [1.19–1.21]). Similarly, depression was associated with increased all-cause mortality (aHR and 95% CI: 1.25 [1.24–1.26]).
CONCLUSIONS The presence of depression in patients with diabetes is associated with higher risk of developing CKD compared with nondepressed patients. Intervention studies should determine if effective treatment of depression in diabetic patients would prevent major renal and cardiovascular complications.
- Received January 8, 2016.
- Accepted May 26, 2016.
- © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.