Determining the effect size of aerobic exercise training on the standard lipid profile in sedentary adults with three or more metabolic syndrome factors: a systematic review and meta-analysis of randomised controlled trials

Objectives To estimate the change in the standard lipid profile (SLP) of adults diagnosed with >= 3 metabolic syndrome (MetS) factors following aerobic exercise training (AET); and to investigate whether study/intervention covariates are associated with this change. Design Systematic review with univariate meta-analysis and meta-regression. Data sources English language searches of online databases from inception until July 2020. Eligibility criteria (1) Published randomised controlled human trials with study population >= 10 per group; (2) sedentary adults with >= 3 MetS factors but otherwise free of chronic disease, not pregnant/lactating; (3) AET-only intervention with duration >= 12 weeks; and (4) reporting pre-post intervention SLP outcomes. Results Various univariate meta-analyses pooled 48 data sets of 2990 participants. Aerobic exercise training significantly (P<.001) improved all lipids (mmol/L mean difference ranges, 95% CIs): total cholesterol, -0.19 (-0.26 to -0.12) to -0.29 (-0.36 to -0.21); triglycerides, -0.17 (-0.19 to -0.14) to -0.18 (-0.24 to -0.13); high-density lipoprotein-cholesterol (HDL-C), 0.05 (0.03 to 0.07) to 0.10 (0.05 to 0.15); and low-density lipoprotein-cholesterol (LDL-C), -0.12 (-0.16 to -0.9) to -0.20 (-0.25 to -0.14). Meta-regression showed that intensity may explain change in triglycerides and volume may explain change in HDL-C and LDL-C. Conclusion Aerobic exercise training positively changes the SLP of sedentary and otherwise healthy adults with >= 3 MetS factors. Adjusting AET intervention training variables may increase the effects of AET on triglycerides and HDL-C. PROSPERO registration number CRD42020151925.

Automated summary

This study analyzed data from nearly 3000 participants undergoing aerobic exercise training, and found that aerobic exercise training had a significant positive impact on improving lipid profiles, particularly on triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. Meta-regression indicated that intensity may explain changes in triglycerides, while volume may explain changes in HDL-C and LDL-C. Adjusting aerobic exercise training intervention variables could enhance the effects on triglycerides and cholesterol levels.