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Bariatric Surgery Improves Nonalcoholic Fatty Liver Disease: Systematic Review and Meta-Analysis

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Abstract

Purpose

Bariatric surgery has been uncovered to relieve nonalcoholic fatty liver disease (NAFLD) in patients with obesity, while current studies have neutral or opposite results. This systematic review and meta-analysis aimed to evaluate the effects of bariatric surgery on NAFLD in patients with obesity.

Materials and Methods

PubMed, Embase, Cochrane Central, and Web of Science databases were performed to obtain publications containing comparison results of liver biopsy before and after bariatric surgery in obesity. Primary outcomes were biopsy-confirmed remission of NAFLD and NAFLD activity scores. Secondary outcomes were liver function. This study was registered with PROSPERO, CRD42021240346.

Results

Thirty-seven studies were included. After bariatric surgery, a biopsy-confirmed resolution of steatosis was improved in 56% of patients, ballooning degeneration in 49%, inflammation in 45%, and fibrosis in 25%. Bariatric surgery significantly decreased mean NAFLD activity scores. RYGB achieved the most obviously improvements in steatosis, and SG attained the most notably ameliorations in fibrosis. The percentage of patients with improved steatosis and hepatic fibrosis in Asian countries was higher than non-Asian countries. The reduction of ALT and AST was 11.95U/L and 6.44 U/L after surgery.

Conclusion

Our study has revealed that bariatric surgery brought out significantly resolution of NAFLD in individuals with obesity. RYGB and SG have been proved to be of benefit to many hepatic parameters, and the improvement of liver steatosis and fibrosis, particularly in Asian countries. It is strongly suggested that bariatric surgery should be considered as a novel treatment for NAFLD.

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Funding

The research is supported by the Wisdom Accumulation and Talent Cultivation Project of the Third Xiangya Hospital of Central South University.

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Authors and Affiliations

  1. Department of General Surgery, Third Xiangya Hospital, Central South University, Changsha, 410013, China

    Hui Zhou, Ping Luo, Pengzhou Li, Guohui wang, Xianhao Yi, Zhibing Fu, Xulong Sun, Beibei Cui, Liyong Zhu & Shaihong Zhu

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  1. Hui Zhou
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  2. Ping Luo
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  3. Pengzhou Li
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  4. Guohui wang
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  5. Xianhao Yi
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  7. Xulong Sun
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  8. Beibei Cui
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  9. Liyong Zhu
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Contributions

H.Z conceptualized the idea for the present review, and H.Z, P.L, XH. Y, PZ. L, GH. W, ZB. F, XL. S, BB. C, LY. Z, and SH. Z collected the data. H. Z and P. L analyzed the data. H. Z wrote the first draft. All authors reviewed and commented on subsequent drafts of the manuscript.

Corresponding authors

Correspondence to Liyong Zhu or Shaihong Zhu.

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Co-first author: Hui Zhou and Ping Luo have contributed equally to this work.

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Zhou, H., Luo, P., Li, P. et al. Bariatric Surgery Improves Nonalcoholic Fatty Liver Disease: Systematic Review and Meta-Analysis. OBES SURG 32, 1872–1883 (2022). https://doi.org/10.1007/s11695-022-06011-1

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