RESUMO
BACKGROUND: Diagnostic criteria for sarcopenia have not been established in Chinese. This study established criteria based on the L3-skeletal muscle index (L3-SMI) and assessed its value for outcomes predicting in cirrhotic Chinese patients. METHODS: Totally 911 subjects who underwent a CT scan at two centres were enrolled in Cohort 1 (394 male and 417 female subjects, aged 20-80 years). The data of those subjects younger than 60 years (365 male and 296 female subjects) were used to determine the reference intervals of the L3-SMI and its influencing factors. Cohort 2 consisted of 480 patients (286 male and 184 female patients) from three centres, and their data were used to investigate the prevalence of sarcopenia and evaluate the value of L3-SMI for predicting the prognosis and complications of cirrhosis. RESULTS: Age and sex had the greatest effects on the L3-SMI (P < 0.001). The L3-SMI scores were clearly higher in male patients than in female patients (52.94 ± 8.41 vs. 38.91 ± 5.65 cm2 /m2 , P < 0.001) and sharply declined in subjects aged ≥ 60 years. Based on the mean -1.28 × SD among adults aged < 60 years, the L3-SMI cut-off value for sarcopenia was 44.77 cm2 /m2 in male patients and 32.50 cm2 /m2 in female patients. Using these values, 22.5% of the cirrhotic patients (28.7% of male patients and 11.9% of female patients) were diagnosed with sarcopenia. Compared with non-sarcopenia individuals, sarcopenia patients had lower body mass index (21.28 ± 3.01 vs. 24.09 ± 3.39 kg/m2 , P < 0.001) and serum albumin levels (31.54 ± 5.93 vs. 32.93 ± 5.95 g/L, P = 0.032), longer prothrombin times (16.39 ± 3.05 vs. 15.71 ± 3.20 s, P = 0.049), higher total bilirubin concentrations (41.33 ± 57.38 vs. 32.52 ± 31.48 µmol/L, P = 0.039), worse liver function (Child-Pugh score, 8.05 ± 2.11 vs. 7.32 ± 2.05, P = 0.001), higher prevalence of cirrhosis-related complications (81.82% vs. 62.24%, P < 0.001) and mortality (30.68% vs. 11.22%, P < 0.001). Overall survival was significantly lower in the sarcopenia group [risk ratio (RR) = 2.643, 95% confidence interval (CI) 1.646-4.244, P < 0.001], accompanied with an increased cumulative incidence of ascites (RR = 1.827, 95% CI 1.259-2.651, P = 0.002), spontaneous bacterial peritonitis (RR = 3.331, 95% CI 1.404-7.903, P = 0.006), hepatic encephalopathy (RR = 1.962, 95% CI 1.070-3.600, P = 0.029), and upper gastrointestinal varices (RR = 2.138, 95% CI 1.319-3.466, P = 0.002). Subgroup analysis showed sarcopenia shortened the survival of the patients with Model For End-Stage Liver Disease score > 14 (RR = 4.310, 95% CI 2.091-8.882, P < 0.001) or Child-Pugh C (RR = 3.081, 95% CI 1.516-6.260, P = 0.002). CONCLUSIONS: Sarcopenia is a common comorbidity of cirrhosis and can be used to predict cirrhosis-related complications and the prognosis.