Complete Resolution of Nonalcoholic Fatty Liver Disease After Bariatric Surgery: A Systematic Review and Meta-analysis

Abstract

This article has an accompanying continuing medical education activity, also eligible for MOC credit, on page e61. Learning Objective-Upon completion of this activity, successful learners will be able to demonstrate an increase in, or affirmation of, their clinical knowledge of nonalcoholic fatty liver disease and identify the role of bariatric surgery in nonalcoholic fatty liver disease treatment. BACKGROUND & AIMS: Bariatric surgery has been reported to lead to complete resolution of nonalcoholic fatty liver disease (NAFLD) following the sustained weight loss induced in obese patients. We performed a systematic review and meta-analysis to evaluate the effects of bariatric surgery on NAFLD in obese patients. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and Web of Science databases through May 2018 for studies that compared liver biopsy results before and after bariatric surgery in obese patients. Primary outcomes were biopsy-confirmed resolution of NAFLD and NAFLD activity score. Secondary outcomes were worsening of NAFLD after surgery and liver volume. The Grading of Recommendations, Assessment, Development, and Evidence approach was conducted to assess overall quality of evidence. RESULTS: We analyzed data from 32 cohort studies comprising 3093 biopsy specimens. Bariatric surgery resulted in a biopsy-confirmed resolution of steatosis in 66% of patients (95% CI, 56%-75%), inflammation in 50% (95% CI, 35%-64%), ballooning degeneration in 76% (95% CI, 64%-86%), and fibrosis in 40% (95% CI, 29%-51%). Patients' mean NAFLD activity score was reduced significantly after bariatric surgery (mean difference, 2.39; 95% CI, 1.58-3.20; P < .001). However, bariatric surgery resulted in new or worsening features of NAFLD, such as fibrosis, in 12% of patients (95% CI, 5%-20%). The overall Grading of Recommendations, Assessment, Development, and Evidence quality of evidence was very low. CONCLUSIONS: Through this systematic review and meta-analysis, we found that bariatric surgery leads to complete resolution of NAFLD in obese patients. However, some patients develop new or worsened features of NAFLD. Randomized controlled trials are needed to further examine the therapeutic benefits of bariatric surgery for patients with NAFLD.

Improvement of non‐alcoholic fatty liver disease after laparoscopic sleeve gastrectomy in Japanese obese patients

“…A systematic review and meta‐analysis showed that bariatric surgery improved NAFLD including NASH . Dixon et al clearly demonstrated that weight reduction after bariatric surgery improved NASH.…”

Covering the Year in CGH: 2019

“…In a systematic review of data from 32 cohort studies comprising 3093 biopsy specimens, bariatric surgery resulted in a biopsyconfirmed resolution of steatosis in 66% of patients (95% CI, 56%-75%), inflammation in 50% (95% CI, 35%-64%), ballooning degeneration in 76% (95% CI, 64%-86%), and fibrosis in 40% (95% CI, 29%-51%). 34 Of note, bariatric surgery resulted in new or worsening features of NAFLD, such as fibrosis, in 12% of patients (95% CI, 5%-20%).…”

Evolution of NAFLD and Its Management

“…Recently, a meta‐analysis conducted on the impact of bariatric surgery on NAFLD found 32 studies (15 retrospective and 17 prospective cohort studies) including over 2649 biopsies performed at follow‐up . Mean weight loss was ≈25%, and surgery resulted in resolution of steatosis in 66%, inflammation in 50%, ballooning degeneration in 76%, and fibrosis in 40%.…”