Exercise Training Enhances Brachial Artery Endothelial Function, Possibly via Improved HDL-C, not LDL-C and TG, in Patients with Coronary Artery Disease: A Systematic Review and Meta-analysis

Abstract

Background: It remains controversial whether exercise training (EX) improves vascular endothelial function (VEF) independent of lipoprotein changes even though these are therapeutic goals for coronary artery disease (CAD).

Objective: The purpose of this study was to systematically review the effects of EX on VEF and blood lipid variables in patients with CAD.

Methods: This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched five electronic databases (CINAHL, Embase, PubMed, SportDiscus, and Web of Science) until March 2024 for studies that met the following criteria: (i) patients with CAD aged ≥ 18 years; (ii) structured EX for ≥ 1 week in randomized or nonrandomized controlled studies; and (iii) measured brachial artery flow-mediated dilation (FMD) with or without blood lipid variables. We calculated effect sizes (ESs) and 95% confidence intervals (CIs) using a random-effects model and conducted subgroup analyses to identify the effect of training factors (duration, intensity, and weekly volume) on outcomes.

Results: In total, 11 studies with 19 trials (629 patients, 60 ± 9 years) met the inclusion criteria. We conducted a separate meta-analysis for each of the four outcome measures: FMD (13 ESs), high-density lipoprotein-cholesterol (HDL-C; eight ESs), low-density lipoprotein cholesterol (LDL-C; eight ESs), and triglycerides (TGs; eight ESs). EX significantly increased FMD (mean ES 0.57; 95% CI 0.44-0.70; P < 0.001) and HDL-C levels (mean ES 0.25; 95% CI 0.12-0.39; P < 0.001) but had no effect on LDL-C and TG. Subgroup analyses for FMD found no significant variation in effect by training factor (duration, intensity, and weekly volume).

Conclusion: EX improves VEF with increased HDL-C, but we found no changes in LDL-C and TG in patients with CAD, suggesting that HDL-C is preferentially associated with exercise-induced VEF improvement.