UC Irvine

Objective

It is not known if patients with diabetes 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.

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 patients with diabetes. Diabetes was ascertained by an ICD-9-CM code for diabetes, an HbA_1c >6.4%, or receiving antidiabetes 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 patients with diabetes would prevent major renal and cardiovascular complications.