Patients with diabetes and depression have increased kidney and heart risks, research suggests

A new study finds that there is an association between depression in patients with diabetes and the risk for cardiovascular disease and kidney disease.
This research from Dr. Miklos Zsolt Molnar, MD, University of Tennessee, Memphis, United States was reported during Kidney Week 2015: American Society of Nephrology Annual Meeting. However, the type of diabetes in this study was not disclosed.
Zsolt and his team evaluated over three million veterans with an estimated glomerular filtration rate (eGFR) of at least 60 mL/min per 1.73 m². This is a test used to check how well the kidneys are working. Levels below 60 mL/min/1.73 m2 for three months or more can be a sign of chronic kidney disease.
Diabetes and depression
People with diabetes are at risk of diabetic nephropathy (kidney disease) if they have continuously high blood sugar levels, while heart disease can affect diabetic patients who don’t manage their condition well over time.
933,211 patients with diabetes were identified, and 340,806 of these were suffering from depression. Almost all of the patients were men and had a mean age of 65.
Depressed patients tended to be somewhat younger, and had slightly higher eGFR, but also more comorbidities prior to the study. During an average follow-up period of 7.3 years, 19 per cent of the cohort of patients with diabetes developed kidney disease.
The presence of depression at baseline was associated with a 20 per cent higher risk of incident kidney disease during follow-up, as well as a 35 per cent increased risk for incident stroke, 24 per cent increased risk for incident coronary heart disease and 25 per cent increased risk of all-cause mortality.
“Depression is one of the most common conditions associated with chronic disease, including diabetes and chronic kidney disease,” said Dr. Molnar. “Comorbid depression in diabetes is associated with poor diabetic control and a poorer quality of life.”
The researchers concluded that depression in diabetes is associated with an increased risk of chronic kidney disease, cardiovascular disease and all-cause mortality. Dr. Molnar added that clinicians need to understand how comorbid depression can contribute to the development of these diseases.
“Appropriate intervention studies are now needed to determine whether treating depression in patients with diabetes would prevent chronic kidney disease and cardiovascular disease.”
However, Dr. Molnar told Medscape Medical News that the presence of depression is only associated with worse cardiovascular and kidney outcomes, and not a cause of them.
“One potential explanation for our findings is that if a patient is depressed, there is a greater likelihood that they will be nonadherent to their regimens, and that might explain these poorer outcomes,” Dr Molnar explained.