The effect of pharmacological treatment and lifestyle modification in patients with nonalcoholic fatty liver disease: An umbrella review of meta-analyses of randomized controlled trials

Nonalcoholic fatty liver disease (NAFLD) is a liver disease that affects approximately 25% of the world's population, and various treatments have been applied for NAFLD patients. We compared the effectiveness of each intervention conducted to treat NAFLD by evaluating meta-analyses of pharmacological interventions and lifestyle modification including diet and exercise. We searched Pubmed/Medline, Embase, and Cochrane Library and included meta-analyses of randomized controlled trials investigating the effects of pharmacological intervention and lifestyle modification on NAFLD. The quality of included meta-analyses was evaluated by AMSTAR-2. If the effect size was expressed as mean difference, it was converted to standardized mean difference based on the random-effects model. A total of 1694 meta-analyses were identified, and 27 meta-analyses were eventually included in the review. Regarding pharmacological interventions, there was a high strength of evidence for the ALT reduction effect of silymarin on inactive controls (SMD = 0.88, p < 0.01, seven trials, 518 participants). Meanwhile, it was confirmed that appropriate diet and exercise were important in reducing liver fat (SMD = 1.51, p < 0.01, 12 trials, 765 participants). This umbrella review assessed the effects of pharmacological interventions and lifestyle modifications in the treatment of NAFLD. The results of this review can be utilized for clinical decisions when treating NAFLD patients.