Association Between Estimated Glomerular Filtration Rate Based on Cystatin C and Grip Strength in Community-Dwelling Japanese Older Adults
Keiko Kabasawa, Kazutoshi Nakamura, Yumi Ito, Junta Tanaka, Ichiei Narita
Abstract
BACKGROUND: Kidney dysfunction is associated with sarcopenia. Estimated glomerular filtration rate based on cystatin C (eGFRcys), an alternative to creatinine-based measures of kidney function eGFR, is not affected by muscle mass. Given that the association of eGFRcys with muscle weakness would be limited, we examined the association in older adults with normal or compromised kidney function. METHODS: This cross-sectional study involved 594 community-dwelling Japanese adults aged ≥40 years living in Yuzawa, Japan. Serum creatinine, cystatin C, and handgrip strength were concurrently measured at a health-check examination in 2015. eGFR was calculated according to the equation developed for the Japanese population using creatinine and cystatin C. Associations of eGFRcys and eGFRcreat with low grip strength (men, <26 kg and women, <18 kg) were analyzed using logistic regression models adjusted to control for potential confounders. RESULTS: Participants (mean age, 74.9 years) included 319 women and 109 individuals with low grip strength. Mean eGFRcys was 75.2 (SD 18.6) mL/min/1.73 m2. Pearson's correlation coefficients of handgrip strength for eGFRcys and eGFRcreat were 0.19 (p < .001) and -0.04 (p = .281), respectively. Multivariate logistic regression analysis showed the adjusted odds ratio (OR) of low grip strength for the highest versus lowest quartile of eGFRcys value was 2.46 (95% confidence interval, 1.03-5.86; p-trend = .026); whereas the comparative adjusted OR for eGFRcreat was 0.67 (95% confidence interval, 0.34-1.32). CONCLUSIONS: Low kidney function as assessed by eGFRcys was associated with muscle weakness in community-dwelling Japanese older adults.