Major depression linked with nearly twice the risk of kidney failure in diabetics

Individuals with diabetes have a high prevalence of depressive symptoms, which has previously been linked with negative health outcomes such as cardiovascular disease and premature death. Little is known about depression's associations with long-term kidney health in diabetics, however.

To investigate, Margaret Yu, MD, MS and Bessie Young, MD, MPH (VA Puget Sound Health Care System and University of Washington) and their colleagues studied 3886 adults with diabetes who were covered by a large health maintenance organization in Washington State. A total of 448 (11.5%) of the patients had major and 327 (8.4%) had minor depressive symptoms. During a median follow-up of 8.8 years, 87 patients (2.2%) developed kidney failure.

Among the major findings:

• Patients with major depressive symptoms had an 85% higher risk of developing kidney failure, after adjusting for various factors including age, sex, race/ethnicity, marital status, education, smoking, body mass index, diabetes duration, baseline kidney function, hypertension, medication use, and adherence to diabetes self-care.

• Minor depressive symptoms were not significantly linked with the development of kidney failure.

"This is the first study to show that major depressive symptoms are associated with a higher risk of kidney failure in patients with diabetes," said Dr. Yu. "As an observational cohort study, we can only identify an association between major depressive symptoms and kidney failure; additional studies are needed to determine whether treatment of depression can reduce the risk of kidney failure."

Also, because the association was not entirely explained by differences in traditional risk factors for kidney disease or diabetes self-care characteristics, more research is needed to determine the mechanisms involved.