Sarcopenia is associated with severe liver fibrosis in patients with non-alcoholic fatty liver disease

Background: Sarcopenia recognises insulin resistance and obesity as risk factors, and is frequently associated with cardiometabolic disorders, including non-alcoholic fatty liver disease (NAFLD). Aim: To test the prevalence of sarcopenia and its relation with the severity of fibrosis (main outcome) and the entire spectrum of liver histology in patients with NAFLD. Methods: We considered 225 consecutive patients with histological diagnosis of NAFLD (Kleiner score). The skeletal muscle index (%) (total appendicular skeletal muscle mass (kg)/weight (kg) × 100), a validated measure of sarcopenia, was assessed by bioelectrical impedance analysis. Sarcopenia was defined as a skeletal muscle mass index ≤37 in males and ≤28 in females. Results: The prevalence of sarcopenia showed a linear increase with the severity of fibrosis, and severe fibrosis (F3–F4) was more than doubled in sarcopenia (48.3% vs. 20.4% in fibrosis ≤F2, P < 0.001). After adjusting for confounders, the association of sarcopenia with severe fibrosis was maintained (OR 2.36, CI 1.16–4.77, P = 0.01), together with age > 50 (OR 6.53, CI 2.95–14.4, P < 0.001), IFG/Diabetes (OR 2.14, CI 1.05–4.35, P = 0.03) and NASH (OR 13.3, CI 1.64–108.1, P = 0.01). Similarly, a significant association was found between sarcopenia and NASH (P = 0.01), steatosis severity (P = 0.006), and ballooning (P = 0.01), but only the association with severe steatosis was maintained (OR 2.02, CI 1.06–3.83, P = 0.03) after adjusting for confounders. Conclusions: In Western patients with NAFLD, with high prevalence of metabolic disorders and advanced liver disease, sarcopenia was associated with the severity of fibrosis and steatosis, independently of hepatic and metabolic risk factors. Studies are needed to assess the impact of interventions to reduce sarcopenia on NAFLD progression.