Continuous aerobic exercise and atherosclerosis-related vascular indices in overweight and obese adults: a Bayesian...

Overweight and obesity accelerate vascular aging and atherosclerosis-related processes through endothelial dysfunction and increased arterial stiffness. Whether continuous endurance training (CET) improves key vascular functional and structural indices in overweight/obese adults remains uncertain, and evidence synthesis is complicated by correlated effect sizes within trials.

To quantify the effects of CET on flow-mediated dilation (FMD), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT) in overweight and obese adults using a Bayesian three-level meta-analysis of randomized controlled trials (RCTs).

PubMed, Web of Science, Cochrane Library, Embase, APA PsycINFO, and EBSCO-SportDiscus were searched from inception to November 2025. Eligible studies were RCTs enrolling adults (18-65 years) with overweight/obesity, comparing CET with usual care/usual lifestyle, and reporting baseline and post-intervention data for FMD, PWV, or CIMT (≥4 weeks). Standardized mean differences (SMDs) for between-group changes were synthesized using a Bayesian three-level random-effects model to account for within-study dependency. Risk of bias was assessed with RoB 2, and certainty of evidence with GRADE.

Seventeen RCTs (746 participants) were included. CET improved FMD (13 studies, 14 effect sizes; μ = 1.14, 95% credible interval [CrI] 0.42 to 1.95), with substantial between-study heterogeneity. CET reduced PWV (7 studies, 9 effect sizes; μ = -0.23, 95% CrI -0.41 to -0.06) with minimal heterogeneity, indicating a consistent benefit on arterial stiffness. The effect on CIMT was not conclusive (5 studies, 5 effect sizes; μ = -0.23, 95% CrI -0.66 to 0.18). Exploratory subgroup analyses suggested the most consistent improvements clustered around interventions lasting 9-12 weeks and performed three sessions per week. GRADE certainty was low for FMD, moderate for PWV, and very low for CIMT, mainly due to risk of bias and imprecision.

In overweight and obese adults, CET yields a "function-first" vascular response-improving endothelial function (FMD) and reducing arterial stiffness (PWV)-while evidence for short- to mid-term structural change in CIMT remains insufficient. Future well-designed RCTs with longer follow-up and standardized vascular assessments are needed to clarify CET effects on vascular remodeling.

https://www.crd.york.ac.uk/prospero/, identifier CRD42024593701.