Effect of exercise intervention on clinical parameters in patients with non-alcoholic fatty liver disease and type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

The effect of exercise on clinical parameters in patients with non-alcoholic fatty liver disease (NAFLD) combined with type 2 diabetes mellitus (T2DM) is unknown. In this meta-analysis, we identified and evaluated the effect of exercise on clinical parameters (BMI, ALT, lipid metabolism, glucose metabolism) in patients with NAFLD combined with T2DM. We conducted a comprehensive search of Medline, Embase, Web of Science, Cochrane Database of Systematic Reviews, and CNKI in December 2022. Data from relevant randomized controlled trials were collected according to inclusion and exclusion criteria. 6 eligible studies with 238 subjects were finally included. We used Review Manager 5.3 for meta-analysis. The study found that exercise improved BMI, ALT, TC, LDL-C, HbA1c, and HOMA-IR, TG, but did not significantly improve HDL-C. Subgroup analysis showed that high-intensity interval training significantly improved BMI (SMD: -0.43, 95% CI: -0.80, -0.06), ALT (SMD: -4.63, 95% CI: -8.42, -0.83), TC (SMD: -0.94, 95% CI: -1.82, -0.07), LDL-C (SMD: -0. 87, 95% CI: -1.26, -0.49), HbA1c (SMD: -1.12, 95% CI: -1.75, -0.48), HOMA-IR (SMD: -0.59, 95% CI: -0.94, -0.25); moderate-intensity continuous training improved ALT (SMD: -3.96, 95% CI: -7.71, -0.21), TG (SMD: -1.59, 95% CI: -2.58, -0.61), HbA1c (SMD: -0.71, 95% CI: -1.37, -0.05), HOMA-IR (SMD: -1.73, 95% CI: -3.40, -0. 06), and to some extent HDL-C levels (SMD: 0.53, 95% CI: 0.04, 1.02); resistance training improved LDL-C (SMD: -2.06, 95% CI: -3.14, -0.98). In conclusion, exercise improved indicators in patients with NAFLD combined with T2DM, but the improvement indicators varied by type of exercise.