No strong link between depression and ESRD in diabetic nephropathy

Depression seems to only weakly affect the progression of diabetic nephropathy patients to end-stage renal disease (ESRD), a new study reports.

Researchers conducted a single-centre prospective study of 486 patients (mean age 67±12 years, 345 men) with type 2 diabetes and advanced diabetic nephropathy. Baseline depression was quantified using the Patient Health Questionnaire 9 (PHQ-9). Outcomes included progression to ESRD, defined as the initiation of renal replacement therapy, as well as pre-ESRD death.

Over a median observation period of 4.4 years, 33.9 percent (n=164) of participants progressed to ESRD while 10.3 percent (n=50) died before reaching ESRD. The cumulative incidence of ESRD was significantly higher in those who had severe depression (p=0.003); pre-ESRD death showed no interaction with depression (p=0.939).

Adjusted analysis, however, found that neither mild (hazard ratio [HR],1.124, 95 percent confidence interval [CI], 0.763–1.656; p=0.555) nor severe (HR, 1.451, 95 percent CI, 0.930–2.265; p=0.101) depression correlated with the risk of ESRD.

Similarly, pre-ESRD death was unrelated to mild (HR, 1.732, 95 percent CI, 0.880–3.411; p=0.112) or severe (HR, 1.141, 95 percent CI, 0.482–2.698; p=0.765) depression.

Even when looking at the individual items in the PHQ-9, researchers saw hardly any interaction between depression and ESRD or pre-ESRD death. The only exception was sleep disturbance, which significantly increased the likelihood of ESRD (p=0.029). But neither the overall somatic nor nonsomatic scores had such an effect on outcomes.

“[M]ultivariate analysis indicated that the presence of serious comorbidities was strongly associated with a higher risk of renal outcome, and may reduce the effect of depressive symptoms and its severity on the renal prognosis in patients with advanced diabetic nephropathy,” the researchers said.