Impact of exercise training on sarcopenia associated with non-alcoholic fatty liver disease (NAFLD) in humans: A systematic review and meta-analysis
Objective: To conduct a systematic review and meta-analyses to assess the efficacy of physical exercise on strength, muscle mass and physical function in adult patients with non-alcoholic fatty liver disease (NAFLD). Design: We conducted a systematic review and meta-analysis of seven studies to investigate the effect of exercise training interventions in muscle strength, muscle mass and physical performance. Data sources: We identified relevant randomised controlled trials (RCT) in electronic databases (PubMed, CINAHL and Scopus). Eligibility criteria: We selected seven RCTs from 66 screened studies. The inclusion criteria were peer-reviewed and English writing articles that included adult patients with liver disease of non-alcoholic origin, applied resistance training, endurance training or both, and assayed at least one variable of sarcopenia. Results: Physical performance criterion improved in the exercise groups (mean differences [MD] 8.26 mL/Kg*min [95% CI 5.27 to 11.24 mL/Kg*min], p < 0.0001) versus the control groups; muscle mass, determined as lean body mass (LBM), showed no evidence of the beneficial effects of exercise versus the control groups (MD 1.01 Kg [95% CI -1.78 to 3.80 Kg], p = 0.48); we did not include muscle strength, as none of the selected studies evaluated it. Summary/conclusion: Exercise training is a useful intervention strategy to treat sarcopenia in patients with NAFLD; it increases their physical performance in the form of aerobic capacity but does not affect LBM. Future research should include muscle strength assessments and resistance training to evaluate the effects of exercise training on sarcopenia in NAFLD patients. PROSPERO reference number CRD42020191471