Frailty and the risk of kidney function decline in the elderly population: the Rugao Longevity and Ageing Study

Abstract Background The diverse risk factors for kidney impairments suggest that kidney function decline is more likely to occur in individuals with a broadly constituted health deficit. Here we conducted a longitudinal cohort study to evaluate the association of baseline frailty status with the risk of estimated glomerular filtration rate (eGFR) decline. Methods Overall, 1269 participants aged 70–84 years from Rugao Longevity and Ageing cohort with 3-year follow-up were included. Frailty was measured using a modified Fried frailty assessment. GFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation. Associations between baseline frailty status and rapid eGFR decline were examined by multinomial logistic analysis. A linear mixed-effect model was used to determine eGFR decline in mL/min/1.73 m2 over the study period comparing those with frail or prefrail at baseline versus those with robust status. Results The mean (± standard deviation) age of participants was 75.1 ± 3.8 years. A total of 144 (11%) participants had rapid eGFR decline by at least 10% during the 3-year follow-up. Compared with robust status, baseline frail status was associated with a 2.48-fold [95% confidence interval (CI) 1.24–4.95] increased risk of rapid eGFR decline after multiple adjustments. In multivariate linear mixed model analysis, subjects with frail status but not prefrail status at baseline had a significant coefficient of −1.70 (95% CI −3.35 to −0.04) for the frail × visit term, which indicates an accelerated eGFR decline compared with robust subjects over the study period (P = 0.044). Conclusions Frailty may serve as an independent biomarker to predict the decline of kidney function.