Systematic Reviews
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jan 6, 2021; 9(1): 102-117
Published online Jan 6, 2021. doi: 10.12998/wjcc.v9.i1.102
Chinese medicine formulas for nonalcoholic fatty liver disease: Overview of systematic reviews
Liang Dai, Wen-Jun Zhou, Linda L D Zhong, Xu-Dong Tang, Guang Ji
Liang Dai, Wen-Jun Zhou, Guang Ji, Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
Linda L D Zhong, Hong Kong Chinese Medicine Clinical Study Centre, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
Xu-Dong Tang, Department of Gastroenterology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing 100091, China
Author contributions: Dai L and Zhou WJ conducted the literature search and data extraction; Dai L and Zhong LLD completed the data analysis; Tang XD and Ji G reviewed the results, made revisions, and contributed equally as corresponding authors; Dai L drafted the manuscript; All authors reviewed and approved the final manuscript as submitted.
Supported by Evidence-based Capacity Building Project for Basic Traditional Chinese Medicine-Specialized Diseases, No. 2019XZZX-XH012; Shanghai Three-year Action Plan for Accelerating the Development of Traditional Chinese Medicine, No. ZY(2018-2020)-CCCX-2002-01.
Conflict-of-interest statement: All the authors declare that they have no competing interests.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Guang Ji, MD, PhD, Chief Physician, Director, Doctor, Professor, Research Scientist, Teacher, Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, No. 725 South Wanping Road, Xuhui District, Shanghai 200032, China. jiliver@vip.sina.com
Received: July 16, 2020
Peer-review started: July 16, 2020
First decision: September 24, 2020
Revised: October 6, 2020
Accepted: November 12, 2020
Article in press: November 12, 2020
Published online: January 6, 2021
Abstract
BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) affects more than one-quarter of the global population. Due to the lack of approved chemical agents, many patients seek treatment from traditional Chinese medicine (TCM) formulas. A variety of systematic reviews have been published regarding the effectiveness and safety of TCM formulas for NAFLD.

AIM

To critically appraise available systematic reviews and sort out the high-quality evidence on TCM formulas for the management of NAFLD.

METHODS

Seven databases were systematically searched from their inception to 28 February 2020. The search terms included “non-alcoholic fatty liver disease,” “Chinese medicines,” “systematic review,” and their synonyms. Systematic reviews involving TCM formulas alone or in combination with conventional medications were included. The methodological quality and risk of bias of eligible systematic reviews were evaluated by using A Measure Tool to Assess Systematic Reviews 2 (AMSTAR 2) and Risk of Bias in Systematic Review (ROBIS). The quality of outcomes was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Seven systematic reviews were ultimately included. All systematic reviews were conducted based on randomized controlled trials and published in the last decade. According to the AMSTAR 2 tool, one systematic review was judged as having a moderate confidence level, whereas the other studies were rated as having a low or extremely low level of confidence. The ROBIS tool showed that the included systematic reviews all had a high risk of bias due to insufficient consideration of identified concerns. According to the GRADE system, only two outcomes were determined as high quality; namely, TCM formulas with the HuoXueHuaYu principle were better than conventional medications in ultrasound improvement, and TCM formulas were superior to antioxidants in alanine aminotransferase normalization. Other outcomes were downgraded to lower levels, mainly because of heterogeneity among studies, not meeting optimal information sample size, and inclusion of excessive numbers of small sample studies. Nevertheless, the evidence quality of extracted outcomes should be further downgraded when applying to clinical practice due to indirectness.

CONCLUSION

The quality of available systematic reviews was not satisfactory. Researchers should avoid repeatedly conducting systematic reviews in this area and focus on designing rigorous randomized controlled trials to support TCM formula applications.

Keywords: Nonalcoholic fatty liver disease, Traditional Chinese medicines, Systematic review, Meta-analysis, Overview, Grading of recommendations assessment, development and evaluation system

Core Tip: Several systematic reviews have reported the efficacy of traditional Chinese medicine (TCM) formulas for nonalcoholic fatty liver disease. This overview critically appraised currently available systematic reviews. Based on high-quality evidence, TCM formulas may benefit ultrasound improvement and alanine aminotransferase normalization. Nevertheless, the quality of evidence should be further downgraded when applying to clinical practice due to indirectness. The included systematic reviews were generally of poor quality, possibly due to the unsatisfactory quality of the available randomized controlled trials (RCTs). Hence, further emphasis should be placed on designing rigorous RCTs instead of repeatedly conducting systematic reviews.