Image of Pietro Ravani, M.D., Ph.D.; Image credit: University of Calgary
Pietro Ravani, M.D., Ph.D.; Image credit: University of Calgary
Image of Pietro Ravani, M.D., Ph.D.; Image credit: University of Calgary
Pietro Ravani, M.D., Ph.D.; Image credit: University of Calgary

The clinical definition of chronic kidney disease (CKD) fails to consider normal, age-related kidney decline and is leading to widespread overdiagnosis in the oldest adults, investigators say.

The issue has been flagged in recent years by physicians. New research presented this weekend at the European Society of Cardiology Congress bolsters the argument that many elderly are being diagnosed and treated for a condition that will never cause symptoms or hasten death.

The current criteria for CKD set by the National Kidney Foundation uses the same measurement threshold for all ages. The question at hand is whether that measurement — glomerular filtration rate (eGFR) — should account for age-related functional decline, according to Pietro Ravani, M.D., Ph.D., and colleagues from the University of Calgary in Canada.

The researchers compared a fixed eGFR threshold of 60 with thresholds of 75, 60, and 45 mL/min/1.73 m2 in adults ages younger than 40, 40 to 64, and 65 years or older, respectively. They found that 75% of those diagnosed with CKD were 65 years or older and had eGFR below the current threshold for diagnosis. They also had normal and/or mild albuminuria (another defining measure). 

The key finding is that the risks of kidney failure and death in this group were similar to those of a control group without CKD, lead author Ping Liu, Ph.D., reported.

“The current criteria for CKD that use the same eGFR threshold for all ages may result in overestimation of the CKD burden in an aging population, overdiagnosis, and unnecessary interventions in many elderly people who have age-related loss of eGFR,” the authors concluded.

The National Kidney Foundation’s clinical practice guidelines from 2002 “dramatically altered” how clinicians think about kidney disease and care for people with CKD, wrote Ann M. O’Hare, M.D., in an editorial accompanying the study. But its proposed system to define and gauge the severity of CKD, and its criteria for a risk-based approach to disease management may have led to some unanticipated and unintended adverse consequences, O’Hare, of University of Washington, Seattle, and colleagues concluded.

Full findings were published in JAMA Internal Medicine.

In related news:
Newly approved finerenone slashes adverse cardiovascular and kidney outcomes in type 2 diabetes trial  The drug (brand name Kerendia) cut the risk of adverse cardiovascular and renal outcomes when compared to placebo in patients with type 2 diabetes. It was effective in all stages of kidney disease, noted the researchers, who presented their results at the European Society of Cardiology Congress this weekend. The Food and Drug Administration approved the drug in July. More than 30% of all patients with diabetes develop chronic kidney disease, according to the National Kidney Foundation.