It may not be surprising that, as we age, various muscles and organs may not work as well as they used to. This also holds true for kidneys. Kidney function naturally declines as we age, but one study now shows that it may decline more in men than in women. Learn more about what the researchers did, what they found, and what it means.* 

What they did

For the study, published in Journal of the American Society of Nephrology, Toralf Melson, M.D., Ph.D. and colleagues at the University Hospital of North Norway recruited 1,837 participants, which included women between the ages of 50 and 62 years, and men between the ages of 50 and 75 years. 

Over an 11-year period, the researchers took more than 4,000 measurements of participants’ kidney function and observed the role(s) that sex differences played in progressive decline of that function. 

The research team also compared “healthy” participants to “non-healthy” participants. A “healthy” individual was defined as: 

• Non-smoking, with no diabetes or hypertension, 
• Non-obese (body mass index of less than 30), 
• Minimal protein found in urine (albumin-to-creatinine ratio less than 3.4), and
• No self-reported previous heart attack, recurring chest pain, open-heart surgery, stroke, cancer, use of cholesterol medication, or use cardiac glycosides (which treat congestive heart failure).

What they found

The average age of participants was 58 years, with approximately 53% of them being women. Initially, women had a lower GFR compared to men. Over time, however, researchers did find a 25% steeper decline in GFR per year in men at older ages compared to women. “Not healthy” participants also had greater GFR decline (0.28 mL/min/1.73 m2  per year) compared to “healthy” participants, but health status did not account for the steeper decline in men. 

What it means

The lower initial kidney function readings in women v. men may help explain why more women receive CKD diagnoses earlier than men, and why more men experience kidney failure as they reach older ages. 

Previous studies have also shown accelerated loss of kidney function to be associated with premature death. More research is needed on age-related kidney function loss and sex disparities to help improve healthy aging and life expectancy among CKD patients. 

*Hornick, I. (2022, October 7). Middle-aged, older men face greater kidney function decline than women in aging. Nephrology News & Issues. Retrieved October 21, 2022, from https://www.healio.com/news/nephrology/20221006/middleaged-older-men-face-greater-kidney-function-decline-than-women-in-aging