Sarcopenia Index Based on Serum Creatinine and Cystatin C is Associated with Mortality, Nutritional Risk/Malnutrition and Sarcopenia in Older Patients

PURPOSE: To investigate the association of sarcopenia index (SI) [(serum creatinine/serum cystatin C) × 100] with mortality, nutritional risk/malnutrition and sarcopenia among hospitalized older adults. SUBJECTS AND METHODS: A prospective analysis was performed in 758 hospitalized older adults. Anthropometric measures and biochemical parameters were carried out for each patient. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) 2019 algorithm. Nutritional risk/malnutrition was defined according to the European Society of Clinical Nutrition and Metabolism (ESPEN) criteria. The logistic regression analysis was employed for the analysis of correlation between the SI and other variables. Cox regression analysis was employed to analyze correlation between the SI and mortality. RESULTS: A total of 758 participants agreed to participate in this study (589 men and 169 women; mean age: 85.6±6.1 years). The median of the follow-up period was 212 days. A total of 112 patients died. A high SI (per 1-SD was 22.1) was independently associated with all-cause mortality (HR per 1-SD = 0.61, 95% CI: 0.47–0.79), nutritional risk/malnutrition (OR per 1-SD = 0.38, 95% CI: 0.29–0.49) and sarcopenia (OR per 1-SD = 0.58, 95% CI: 0.45–0.74). High SI was positively correlated with albumin (r = 0.32, P < 0.001), hemoglobin (r = 0.24, P < 0.001), body mass index (BMI) (r = 0.12, P = 0.001), waist circumference (WC) (r = 0.08, P = 0.046), calf circumference (CC) (r = 0.45, P < 0.001), hand grip strength (HGS) (r = 0.52, P < 0.001) and negatively correlated with triglyceride glucose (TyG) (r = −0.11, P = 0.007). CONCLUSION: The SI based on serum cystatin C and creatinine is associated with long-term mortality, nutritional risk/malnutrition and sarcopenia in hospitalized older Chinese patients.