CKD Regression, Death More Likely than Kidney Failure with Advancing Age, Study Finds

For adults with chronic kidney disease (CKD), disease regression is at least as common as disease progression or kidney failure, especially as the competing risk of death increases with age, according to results of a study published in JAMA Network Open (1).

The new analysis documents regression of incident CKD across different ages and degrees of severity. Ping Liu, PhD, and coauthors note that as the risk of death increases with advancing age, the likelihood of CKD regression decreases to a lesser extent relative to the risk of CKD progression or kidney failure. “Therefore, the aging of the general population may not necessarily translate into increased CKD burden for patients and health services,” the authors state. “[The] findings suggest that CKD regression should be considered in the allocation of health resources and in patient counseling.” Ping Liu is affiliated with the Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.

The researchers used linked administrative and laboratory databases to identify adult residents of Ontario, Canada, with incident CKD. Women accounted for 55.2% of those studied. Based on estimated glomerular filtration rate (eGFR), CKD was classified as mild (eGFR 45 to 59 mL/min/1.73 m ²) in 81,320 patients, moderate (30 to 44 mL/min/1.73 m²) in 35,929 patients, and severe (15 to 29 mL/min/1.73 m ²) in 12,237 patients. Those in the mild CKD group had a mean age of 72.4 years, compared with 77.1 years for those in the moderate group, and 76.6 years for those in the severe group.

The researchers analyzed rates of CKD progression and regression by age, based on a sustained increase or decrease in the eGFR category for more than 3 months or a 25% or greater increase or decrease in eGFR, respectively. Other outcomes included kidney failure (eGFR less than 15 mL/min/1.73 m²) and death. The analysis included measures to minimize the effects of regression of CKD after acute kidney injury or owing to the effects of variability in eGFR measurements.

For individuals 65 or under, annual CKD incidence was 180 per 100,000 population. For those 85 or older, annual CKD incidence increased to 7250 per 100,000 population. In all three categories of mild, moderate, or severe kidney disease, the 5-year probability of regression was similar to that of progression: 14.3% versus 14.6% in the mild CKD group, 18.9% versus 16.5% in the moderate CKD group, and 19.3% versus 20.4% in the severe CKD group.

In patients with moderate CKD, 5-year mortality increased from 9.6% for those under 65 to 48.4% for those 85 or older. The aging-related increase in the severe CKD group was from 10.8% to 60.2%. When the competing risk of death was considered, the risk of disease progression or kidney failure decreased significantly: from 32.3% at age under 65 to 9.4% at age 85 or older in patients with the moderate CKD group and from 55.2% to 4.7% in those with severe CKD. Aging had a lesser effect on the probability of CKD progression: from 22.5% at age under 65 to 15.4% at age 85 or older in the moderate CKD group and from 13.9% to 18.7% in the severe CKD group.

“The burden CKD is expected to increase worldwide as the global population ages, potentially increasing the demand for nephrology services,” the authors state. “Understanding whether CKD inevitably progresses or may regress can inform clinical decision-making and health policy.”