Depression may increase the risk of kidney failure

Lead investigator, Dr. Willem Kop (Department of Medical Psychology and Neuropsychology at the University of Tilburg, the Netherlands) and colleagues studied 5,785 people from four counties across the United States for 10 years. The participants were 65 years and older and not yet on dialysis. They completed a questionnaire measuring depressive symptoms and a broad range of medical measurements, including estimated glomerular filtration rate (eGFR) and risk factors for kidney and heart diseases. The investigators examined whether depression predicted the onset of kidney disease or other medical problems in which the kidneys play a critical role.

According to the results, depression coincided with the presence of chronic kidney disease (CKD) and was 20% more common in individuals with kidney disease than those without kidney disease. The study shows that depression predicted subsequent rapid decline in kidney function, new onset clinically severe kidney disease (or end-stage renal disease), and hospitalizations that were complicated by acute kidney injury. When the investigators corrected for the long-term effects of other medical measures, the predictive value of depression for hospitalizations with acute kidney injury remained high.

Take home message: "People with elevated depressive symptoms have a higher risk of subsequent adverse kidney disease outcomes. This is partially explained by other medical factors related to depression and kidney disease. But, the association with depression was stronger in patients who were otherwise healthy compared to those who had co-existing medical disorders such as diabetes or heart disease," explains Kop.

The investigators are currently analyzing which factors may explain the association with depression, which could include delayed seeking of medical care and miscommunications between patient and physicians and important biological processes associated with depression, such as the immune and nervous systems.

Study co-authors include Stephen Seliger (University of Maryland, Nephrology); Jeffrey Fink (University of Maryland Medical System, Department of Medicine, Division of Nephrology); Ronit Katz (University of Washington, Biostatistics); Michelle Odden (University of California, Berkeley, Department of Epidemiology); Linda Fried (Veterans Affairs Pittsburgh Health System); Dena Rifkin (UCSD and VASDHS, Medicine); Mark Sarnak (Tufts-New England Medical Center, Medicine); and John Gottdiener (University of Maryland, School of Medicine, Medicine).