Serum creatinine-to-cystatin C ratio as an indicator of sarcopenia in hemodialysis patients
Takahiro Yajima, Kumiko Yajima
Abstract
Background and aims In hemodialysis patients, sarcopenia is common and related to morbidity and mortality. In non-dialysis patients, the serum creatinine-to-cystatin C (Cre/Cys-C) ratio is a marker of sarcopenia. Its clinical utility in hemodialysis populations, however, is still unknown. Our study aimed to determine whether sarcopenia could be detected using the Cre/Cys-C ratio in hemodialysis patients. Methods This retrospective cross-sectional study included 85 hemodialysis patients whose handgrip strength (HGS) and bioimpedance analysis-estimated skeletal muscle index (SMI) were assessed. Sarcopenia was diagnosed as a combination of reduced muscle strength (women: HGS <18 kg; men: HGS <28 kg) and decreased muscle mass volume (women: SMI <5.7 kg/m 2 ; men: SMI <7.0 kg/m 2 ). Results Sarcopenia was observed in 33 (38.8%) patients. Patients with sarcopenia had a significantly lower Cre/Cys-C ratio than those without (1.3 ± 0.2 vs 1.7 ± 0.3, respectively; p < 0.0001). The Cre/Cys-C ratio was independently associated with HGS (β = 0.303, p = 0.011) and SMI (β = 0.376, p = 0.0007). After adjustment for sex and age, the C-statistic of the Cre/Cys-C ratio that predicted sarcopenia was 0.898 (95% CI [0.827, 0.969], p < 0.0001). Moreover, as Cre/Cys-C ratios increased, the risk of sarcopenia significantly decreased (adjusted OR: 0.665 for each 0.1 increase in the Cre/Cys-C ratio) (95% CI [0.501, 0.857], p = 0.0002). Conclusion The Cre/Cys-C ratio may be a helpful prediction tool for sarcopenia in patients receiving hemodialysis.