Serum creatinine-to-cystatin C ratio as an indicator of sarcopenia in hemodialysis patients

Abstract

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. 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 <18kg; men: HGS <28kg) and decreased muscle mass volume (women: SMI <5.7kg/m2; men: SMI <7.0kg/m2). 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). The Cre/Cys-C ratio may be a helpful prediction tool for sarcopenia in patients receiving hemodialysis.