Renal function and comprehensive frailty in community-dwelling older adults: cross-sectional and longitudinal...

Chronic kidney disease is common older adults, yet its role in overall frailty remains unclear, particularly when assessed using the Questionnaire for Medical Checkup of Old-Old (QMCOO). This study investigated both cross-sectional and longitudinal links between renal function and multidomain frailty in community-dwelling older adults.

We analyzed data from 4621 participants (mean age: 80.1 years; men:39.5%) who underwent health checkups in Nobeoka City, Japan (April 2020 to March 2021). Renal function was assessed using estimated glomerular filtration rate (eGFR) and grouped as ≥ 60, 45-59, 30-44, and < 30 mL/min/1.73 m². Multidomain frailty was defined as a QMCOO score ≥ 4 and included physical, oral, nutritional, cognitive, and social domains. For longitudinal analysis, 2398 participants without frailty at baseline were followed for 1 year; incident frailty was evaluated using logistic regression.

Frailty prevalence increased as renal function declined (21.5%, 23.2%, 32.8%, and 38.7% across eGFR groups). Similar patterns were observed for physical, oral, nutritional, and cognitive domains, but not for social frailty. Over 1 year, participants with eGFR < 30 had a higher risk of developing frailty than those with eGFR ≥ 60 (adjusted odds ratio 2.37; 95% confidence interval [CI] 1.10-5.20).

Declined kidney function was independently associated with both higher prevalence and incidence of comprehensive frailty, particularly in physical, oral, nutritional, and cognitive domains. Preserving renal function may help reduce frailty risk in older adults.