Efficacy of Ursodeoxycholic Acid in Nonalcoholic Fatty Liver Disease: An Updated Meta-Analysis of Randomized Controlled Trials

Background Nonalcoholic fatty liver disease (NAFLD) is a kind of chronic liver disease among general population. Recent years, more and more new experiments have made the role of ursodeoxycholic acid (UDCA) become clearer. In this meta-analysis, we analyzed the efficacy of ursodeoxycholic acid (UDCA) for the treatment of nonalcoholic fatty liver disease (NAFLD). Methods We searched the Web of Science, Pubmed, Embase and Cochrane library databases for relavent studies published before March 1, 2019. We examined 134 randomized controlled trials (RCTs) that investigated the effectiveness of UDCA in NAFLD against placebo or other treatments. Next, we conducted meta-analysis by Stata(version 12.0) to examine the change among several indices: Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), Alkaline phosphatase (AP), total bilirubin and albumin. Results Following the application of different inclusion and exclusion criteria, 9 articles with 1106 participants were finally selected. The forest plot displayed that UDCA treatment can significantly decrease the ALT levels among the NAFLD patients (SMD=0.17,95%CI [0.03 to 0.3], P=0.07). However, UDCA treatment did not significantly affect the AST, GGT, AP, total bilirubin and albumin levels. Further, the subgroup analyses suggested the significant role of UDCA treatment in different geographical regions, age group and treatment duration (P=0.003 in people from Europe, P=0.001 in people older than 50 years and P=0.008 in longer duration(>6 months)). Conclusion In this study, several indices we analyzed among 9 articles. UDCA treatment was found beneficial in lowering the ALT levels in NAFLD patients. The remaining indices like AST, GGT, AP showed non-significant changes in this analysis. This could be attributed for the insufficient number of trials because all parameters were not analyzed in each individual RCT. Therefore, future meta-analysis will be required to fully confirm and validate the efficacy of UDCA in NAFL.