Exercise Does Not Independently Improve Histological Outcomes in Biopsy-Proven Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Abstract

Introduction: The independent effect of exercise on liver histology in non-alcoholic fatty liver disease (NAFLD) remains unclear. As such, we conducted a systematic review and meta-analysis of the effect of exercise alone on histological endpoints in biopsy-proven NAFLD. Materials and Methods: A systematic literature search was conducted to include controlled clinical trials investigating the effect of exercise alone on liver histology in biopsy-proven NAFLD. Meta-analysis was conducted for histological outcomes with available data from a minimum of three studies. Pooled estimates of the effect of exercise on histological endpoints were calculated using random-effects models. Results: We identified three controlled clinical trials that assessed the independent effect of exercise on histological outcomes in patients with biopsy-proven NAFLD. The studies consisted of 72 total participants, including 40 subjects in the exercise intervention and 32 individuals in the comparison group. Meta-analysis showed that exercise did not significantly improve Brunt grade, NAFLD activity score, and fibrosis in NAFLD. Discussion: Exercise alone may not lead to significant histopathological improvement in NAFLD. Future well-powered randomized controlled trials are needed to better characterize the impact of exercise on histological outcomes and clinical endpoints.