The effect of aerobic exercise on metabolic parameters of patients with non-alcoholic fatty liver disease: systematic review and meta-analysis

The aim of this study was to determine and evaluate the effect of aerobic exercise on fasting blood glucose, Insulin, Insulin resistance, Glycosylated hemoglobin (Hemoglobin A1C), Lipid profile as important indicators of non-alcoholic fatty liver disease.This research is a systematic review and meta-analysis that was conducted in 2021. For the present study, databases, ScienceDirect, PubMed, Scopus, science of Web, SID, Magiran and Google Scholar from 2010 to 2021, were searched along with keywords. After the initial screening, the full text of the articles was evaluated and the articles that met the inclusion criteria were analyzed. A total of 120 articles were reviewed, of which 16 articles met the criteria for entering the systematic review and meta-analysis. Accordingly, 710 people with fatty liver disease were divided into two groups of control and experimental group of 307 and 403 people, respectively. The mean age of the subjects in the present study was 52±10 years. The intervention effects were evaluated using the mean difference (MD) and the random effects model. Data were analyzed using effect size tests, bias analysis and heterogeneity analysis and by STATA software.Meta-analysis results indicated that endurance training in general significantly reduced glucose levels (P=0.004, SDM=-0.26, SE=0.09), insulin (P=0.01, SDM=-0.29, SE=0.11), HOMA-IR (P=0.01, SDM=-0.28, SE=0.11), Hba1c (P=0.001, SDM=-0.33, SE=0.12), triglycerides (P=0.02, SDM=-0.31, SE=0.13) and LDL (P=0.03, SDM=-0.21, SE=0.1).The results of meta-analysis did not show a significant effect on HDL levels after aerobic exercise in patients with fatty liver (P=0.97, SDM=0, SE=0.09). Endurance training improves the levels of glucose, insulin, Hba1c, Homa-IR, triglyceride, and LDL; although, there was no significant change in HDL levels due to endurance training. However, there is still a need for further research in this area.