Effects of exercise modalities on arterial stiffness and wave reflection: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background and objectives: Physical activity is associated with lower cardiovascular and all-cause mortality. However, the effects of different exercise modalities on arterial stiffness are currently unclear. Our objectives were to investigate the effects of exercise modalities (aerobic, resistance or combined) on pulse wave velocity (PWV) and augmentation index (AIx), and to determine whether the effects on these indices differed according to the participants' or exercise characteristics.

Methods: We searched the Medline, Embase and Cochrane Library databases from inception until April 2014 for randomized controlled trials lasting ≥ 4 weeks investigating the effects of exercise modalities on PWV and AIx in adults aged ≥ 18 years.

Results: Forty-two studies (1627 participants) were included in this analysis. Aerobic exercise improved both PWV (WMD: -0.63 m/s, 95% CI: -0.90, -0.35) and AIx (WMD:-2.63%, 95% CI: -5.25 to -0.02) significantly. Aerobic exercise training showed significantly greater reduction in brachial-ankle (WMD: -1.01 m/s, 95% CI: -1.57, -0.44) than in carotid-femoral (WMD: -0.39 m/s, 95% CI: -0.52, -0.27) PWV. Higher aerobic exercise intensity was associated with larger reductions in AIx (β: -1.55%, CI -3.09, 0.0001). In addition, aerobic exercise had a significantly larger effect in reducing PWV (WMD:-1.0 m/s, 95% CI: -1.43, -0.57) in participants with stiffer arteries (PWV ≥ 8 m/s). Resistance exercise had no effect on PWV and AIx. There was no significant effect of combined exercise on PWV and AIx.

Conclusions: We conclude that aerobic exercise improved arterial stiffness significantly and that the effect was enhanced with higher aerobic exercise intensity and in participants with greater arterial stiffness at baseline.

Trial registration prospero: Database registration: CRD42014009744.

Figure 1. Flow diagram of the process used in selection of the randomized controlled trials included in this systematic review and meta-analysis.

Figure 2. Forest plot showing the effect of aerobic exercise on pulse wave velocity (PWV).

AIT, aerobic interval training; CMT, continuous moderate-intensity training; ID, intradialytic; HB, home-based.

Figure 3. Associations between pulse wave velocity (PWV) and changes in heart rate and mean arterial blood pressure in response to (a) aerobic (b) resistance (c) combined aerobic and resistance exercise intervention.

(d) Association between augmentations index (AIx) and changes in heart rate and mean arterial blood pressure in response to aerobic exercise intervention. Each study is depicted by a circle where the circle size represents the degree of weighting for the study based on participant numbers in the study.

Figure 4. Forest plot showing the effect of resistance exercise on pulse wave velocity (PWV).

ERT, eccentric resistance training; CRT, concentric resistance training; UL, upper limb; LL, lower limb; ALRT, low intensity after high intensity resistance training; BLRT, low intensity before high intensity resistance training.

Figure 5. Forest plot showing the effect of combined (aerobic and resistance) exercise on pulse wave velocity (PWV).

1DW, 1 day per week, 2DW, 2 days per week; BRT, aerobic training before resistance training, ART, aerobic training after resistance training.

Figure 6. Forest plot showing the effect of aerobic exercise on augmentation index (AIx).

intradialytic; HB, home-based; FG, football group, RG, running group.

Figure 7. Associations between aerobic exercise intervention characteristics and augmentation index (AIx): (a) relative intensity; (b) absolute intensity; (c) session frequency; (d) session duration.

Each study is depicted by a circle where the circle size represents the degree of weighting for the study based on participant numbers in the study.

Figure 8. Forest plot showing the effect of resistance exercise intervention on augmentation index (AIx).