Myostatin in combination with creatine phosphokinase or albumin may differentiate patients with cirrhosis and sarcopenia

In patients with liver cirrhosis (LC), sarcopenia is correlated with frequent complications and increased mortality. Myostatin, a myokine, is a potential biomarker of skeletal mass and/or sarcopenia. The aim of this study was to examine the association between myostatin and muscle mass and evaluate myostatin as a biomarker of sarcopenia in LC. Skeletal muscle index (SMI) and myosteatosis were evaluated by computed tomography scan. Muscle quantity and quality along with muscle strength and function were used to diagnose sarcopenia. Serum myostatin was measured by ELISA. One hundred and fifteen consecutive patients with LC [72.2% male, median age 59 yr (IQR 52-67), MELD 12 (8-16), 28.7% with compensated LC] were included. Low SMI was diagnosed in 49.6% and sarcopenia in 34.8% (21.7% severe). Myostatin levels were lower in low (P < 0.001) compared with patients with normal SMI and were strongly correlated with SMI in MELD score > 15 (r = 0.571, P < 0.001). Myostatin was also lower in patients with sarcopenia compared with those without (P < 0.001) and even lower in severe sarcopenia (P < 0.001). In multivariate analysis, myostatin, age, and albumin remained significant predictors of low SMI after adjustment for sex, MELD, and creatine phosphokinase (CPK). Similarly, myostatin and age predicted sarcopenia after adjustment for sex, MELD, CPK, and albumin. The ratios log10myostatin-to-CPK or albumin-to-myostatin were found to have acceptable diagnostic accuracy in ruling out sarcopenia in total patients. However, the best diagnostic performance was shown in MELD > 15 (AUROC 0.829 or 0.801, respectively). Myostatin is independently associated with both skeletal muscle mass and sarcopenia. Myostatin in combination with CPK or albumin are good surrogate markers in excluding sarcopenia. NEW & NOTEWORTHY Serum levels of myostatin were significantly lower in cirrhotic patients with impaired skeletal mass index (SMI) and sarcopenia than those without. Serum levels of myostatin have a positive correlation with SMI. Myostatin levels are independently associated with sarcopenia, diagnosed according to the latest criteria, in patients with cirrhosis. Myostatin in combination with creatine phosphokinase or albumin have good accuracy excluding sarcopenia in patients with cirrhosis.