Analysis of variance

Statistics

Arterial stiffness

Cardiology

Blood pressure

Mathematics

Repeated measures design

Physical therapy

Meta-analysis

Internal medicine

Pulse wave velocity

Medicine

Physical medicine and rehabilitation

Medicine & Science in Sports & Exercise

BACKGROUND: Cardiovascular disease (CVD) is the number one cause of death in the U.S., taking one life every 36 seconds. Sedentarism and insufficient physical activity are CVD risk factors as they contribute to arterial stiffness. Arterial stiffness is the compromised ability of blood vessels to expand and recoil. This can be assessed by pulse wave velocity (PWV), the velocity at which pulse pressure waves are propagated down the arterial tree. The purpose of this meta-analysis is to investigate the effect of aerobic (AE) and resistance (RE) exercise on PWV as a measure of arterial stiffness over time. METHODS: Electronic databases (PubMed, SPORTDiscus) were searched from inception to July 2020. Extracted data was used to determine the change effects of time (change in PWV with weeks of training) and group (exercise intervention vs. control). To account for effect-size dependency, a 3-level model was conducted with restricted maximum likelihood estimation. The 3 sources of variance taken into account included: variance at the level of the subject (Level 1), variance between effect sizes extracted from the same study (Level 2), and variance between studies (Level 3). RESULTS: Initially, 110 studies were identified. After evaluation of study eligibility, data from 6 studies involving 246 participants were extracted for analysis. The 6 studies included 12 experimental arms (AE = 5, RT = 2, control = 5). Compared across all studies and exercise and control groups, PWV changed by -2.87 cm/s per week (95%: -6.73 to 0.99, P = 0.139). The majority of the variance was at levels 3 (I2 = 56%) and 2 (I2 = 25%). Compared to the control group, for the exercise group PWV changed by -5.10 cm/s per week (95%: -12.65 to 2.44, P = 0.177). When the exercise groups were categorized by exercise modality, compared to control group the AE group changed by -5.35 cm/s per week (95%CI: -13.10 to 2.38, P = 0.167), and the RT group by -3.23 cm/s per week (95%CI: -33.99 to 27.54, P = 0.831). CONCLUSIONS: The findings were inconclusive. With an exercise intervention PWV did decrease each week, but the change did not reach significance. The effects do appear to be stronger for AE compared to RT. Considering the study design differences, small number of studies, and the inability to identify whether the change in PWV is non-linear, further research is warranted.

The Effect Of Exercise On Change In Arterial Stiffness Over Time: A Meta-analysis