Meta-Analysis
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2019; 7(12): 1444-1455
Published online Jun 26, 2019. doi: 10.12998/wjcc.v7.i12.1444
Relationship between circulating irisin levels and overweight/obesity: A meta-analysis
Jue Jia, Fan Yu, Wei-Ping Wei, Ping Yang, Ren Zhang, Yue Sheng, Yong-Qin Shi
Jue Jia, Fan Yu, Wei-Ping Wei, Ping Yang, Yue Sheng, Yong-Qin Shi, Affiliated Hospital of Jiangsu University, Zhenjiang 212001, Jiangsu Province, China
Ren Zhang, Department of Library of Jiangsu University, Zhenjiang 212001, Jiangsu Province, China
Author contributions: Jia J conceived and designed the study; Jia J, Yu F, and Zhang R searched the related articles; Yang P, Wei WP, Sheng Y, and Shi YQ analyzed the data; Jia J and Yu F wrote the manuscript; all authors read and approved the final manuscript.
Supported by the National Natural Science Foundation of China, No. 81500351; the Youth Medical Talent Project of Jiangsu Province, No. QNRC2016842; the Jiangsu University Affiliated Hospital "; 5123"; Talent Plan, No. 51232017305; and the 169 Talent Project of Zhenjiang.
Conflict-of-interest statement: The authors deny any conflict of interest.
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 which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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: Jue Jia, MD, Lecturer, Associate Chief Physician, Affiliated Hospital of Jiangsu University, No. 438, Jiefang North Road, Jingkou District, Zhenjiang 212001, Jiangsu Province, China. 1000011436@ujs.edu.cn
Telephone: +86-511-85031120 Fax: +86-511-85019237
Received: February 25, 2019
Peer-review started: February 26, 2019
First decision: April 18, 2019
Revised: April 27, 2019
Accepted: May 2, 2019
Article in press: May 2, 2019
Published online: June 26, 2019
Processing time: 121 Days and 15.5 Hours
Abstract
BACKGROUND

Currently, the findings about irisin as a novel myokine related to obesity are inconsistent in overweight/obese people. To our knowledge, no systematic analysis has been conducted to evaluate the relationship between irisin levels and overweight/obesity.

AIM

To evaluate the association between circulating irisin levels and overweight/obesity.

METHODS

The Cochrane Library, MEDLINE, SCOPUS, and the ISI Web of Science were searched to retrieve all of the studies associated with circulating irisin levels and overweight/obesity. Standard mean difference values and 95% confidence intervals (CI) were estimated and pooled using meta-analysis methodology.

RESULTS

A total of 18 studies were included in our meta-analysis containing 1005 cases and 1242 controls. Our analysis showed that the circulating irisin level in overweight/obese people was higher than that in overall healthy controls (random effects MD = 0.63; 95%CI: 0.22-1.05; P = 0.003). In the subgroup analysis by ethnicity, the irisin level was higher in overweight/obesity people than that in controls in Africa (random effects MD = 3.41; 95%CI: 1.23-5.59; P < 0.05) but not in European, Asian, or American populations. In addition, in a subgroup analysis by age, the results showed that obese children exhibited a higher irisin level than controls (random effects MD = 0.86; 95%CI: 0.28-1.43; P < 0.05).

CONCLUSION

This meta-analysis provides evidence that circulating irisin is higher in obese individuals compared to healthy controls and it is important to identify the relationship between circulating irisin levels and overweight/obesity in predicting overweight/obesity.

Keywords: Irisin; Overweight/obesity; Myokines; Body mass index

Core tip: This study is the first meta-analysis that systematically assessed circulating irisin in overweight/obese people. This meta-analysis showed that circulating irisin levels were higher in obese individuals than in healthy controls. It also suggested that circulating irisin levels were higher in obese people in Africa than in controls. This meta-analysis further suggested that obese children exhibited a higher irisin level than controls.