Prospective histopathologic evaluation of lifestyle modification in nonalcoholic fatty liver disease: a randomized trial

Background and aims: Nonalcoholic fatty liver disease (NAFLD) is now recognized as part of the metabolic syndrome, and is specifically related to obesity and insulin resistance. Lifestyle modification is advocated for the treatment of NAFLD, but few studies have evaluated its impact on liver histology. The purpose of this study was to investigate which, if any, specific diet and exercise recommendations are associated with histopathologic changes. Methods: A total of 56 participants were randomly assigned to 1 of 4 lifestyle modification subgroups for 6 months: standard care, low-fat diet and moderate exercise, moderate-fat/lowprocessed- carbohydrate diet and moderate exercise, or moderate exercise only. All subjects had biopsy-proven NAFLD, to include nonalcoholic steatohepatitis (NASH), and received a repeat 6-month biopsy to detect histopathologic changes. Other measures included blood assay of liver enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase), fasting glucose, serum insulin, lipid panel, body weight, dietary intake, fat mass, and fitness level. Results: Among the 41 participants who completed the study (88% with NASH), a significant change was found in pre- to post-NAFLD activity score in the group as a whole (p < 0.001) with no difference detected between subgroups (p = 0.31). Our results confirm that lifestyle modification is effective in improving NAFLD and NASH. Conclusions: Regardless of intervention group, lifestyle modification improved liver histology, as verified by repeat biopsy, after a 6-month intervention. This study reinforces the importance of lifestyle modification as the primary treatment strategy for patients with NAFLD.