Glomerular filtration rate by different measures and albuminuria are associated with risk of frailty: the Rugao Longitudinal Ageing Study.

BACKGROUND AND AIM: A decreased estimated glomerular filtration rate (eGFR) is associated with frailty, but the association between kidney function and frailty using multidimensional assessments has not been entirely examined. We aimed to investigate whether albuminuria and the eGFR using different biomarkers were associated with frailty.

METHODS: A total of 1830 older adults were included. Kidney function was assessed by the eGFR (based on combined creatinine-cystatin C [eGFRcr-cys ]) and β2 -microglobulin [eGFRB2M ]) and urine albumin-creatinine ratio (UACR). Frailty was measured by the Fried phenotype (FP) and frailty index (FI). Logistic regression models were used to investigate cross-sectional and longitudinal associations of baseline kidney measures with prevalent and incident frailty.

RESULTS: At baseline, kidney function was associated with prevalent frailty. During the 2-year follow-up, a decreased eGFR (per 10 units) was associated with an increased risk of incident frailty using the FP (eGFRcr-cys : OR 1.18, 95% CI 1.03-1.35; eGFRB2M : OR 1.14, 95% CI 1.02-1.29, respectively) and FI (eGFRB2M : OR 1.18, 95% CI 1.04-1.65). An increased logUACR was associated with a higher risk of incident frailty using the FP (OR 1.18, 95% CI 1.03-1.35). Additionally, individuals with chronic kidney disease (CKD) had a higher risk of incident frailty using the FP (eGFRcr-cys : OR 2.13, 95% CI 1.28-3.47; eGFRB2M : OR 1.58, 95% CI 1.10-2.29, respectively) and FI (eGFRcr-cys : OR 1.97, 95% CI 1.15-3.32; eGFRB2M : OR 1.51, 95% CI 1.03-2.24, respectively).

CONCLUSION: Kidney function decline and CKD were associated with an increased risk of prevalent and incident frailty in older adults. Physicians should pay more attention to monitoring frailty status in older adults with CKD, even in those with kidney function decline.