Higher albumin:creatinine ratio and lower estimated glomerular filtration rate are potential risk factors for decline of physical performance in the elderly: the Cardiovascular Health Study

Introduction. Mildly reduced renal function and elevated urine protein levels are each prospectively associated with hip fracture risk in older adults. Here we determine whether these markers are associated with reduced appendicular muscle performance. Methods. We prospectively examined the associations of urine albumin:creatinine ratio (ACR) and reduced estimated glomerular filtration rate (eGFR) with longitudinal changes in grip strength and gait speed >2 years in 2317 older community-dwelling men and women (median age 77 years). The median ACR was 9.8 [interquartile range (IQR) 5.40-21.50] mg/g creatinine and the median eGFR was 71.6 (IQR 59.1-83.56) mL/min/1.73m(2). Models were adjusted for demographic factors, clinical history and biochemical measures in four candidate pathways: diabetes, oxidative stress, inflammation and fibrosis. Results. In demographic- and covariate-adjusted models, a 2-fold higher baseline urine ACR was associated with longitudinal changes of -0.17 kg [95% confidence interval (CI) -0.29 to -0.06) in grip strength and -1.10 cm/s (95% CI -1.67 to -0.53) gait speed per year. Corresponding estimates for a 10 mL/min/1.73m2 lower baseline eGFR were -0.13 kg (95% CI -0.23 to -0.04) and -0.89 cm/s (95% CI -1.37 to -0.40), respectively. The associations of a 2-fold higher baseline ACR and a 10 mL/min/1.73m2 lower baseline eGFR using cystatin C with grip strength and gait speed were equivalent to -1.2-1.9 additional years of age. Adjustment for covariates in candidate pathways did not attenuate these estimates. Conclusions. In older adults, higher ACR and lower eGFR are potential risk factors for a decline of physical performance >2 years.