Improved brachial artery shear patterns and increased flow‐mediated dilatation after low‐volume high‐intensity interval training in type 2 diabetes

Abstract

Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilatation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilatation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate-intensity training (CMIT). Seventy-five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85-90% maximal heart rate (HR ) and 2 min at 55-60% HR . The CMIT group intervention was 42 min of exercise at 70% HR for three sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow, and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there was no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0.78 baseline, 4.04 ± 1.28% follow-up) (P < 0.05). Retrograde shear in the LV-HIIT group decreased significantly (P < 0.05), and no significant decrease in retrograde shear was seen in the CMIT group. Anterograde shear after LV-HIIT increased significantly (P < 0.05) but was unchanged in the CMIT group. However, oscillatory shear index in both exercise groups decreased significantly (P = 0.029). Nitrite/nitrate (NOx) level increased in both exercise groups, but the increase was greater in the LV-HIIT group (P < 0.001). The results indicate that by increasing NOx, HIIT decreases the oscillatory shear-induced improvement in FMD and outward artery remodelling in patients with type 2 diabetes.

Comparative Effectiveness of High-Intensity Interval Training and Moderate-Intensity Continuous Training for Cardiometabolic Risk Factors and Cardiorespiratory Fitness in Childhood Obesity: A Meta-Analysis of Randomized Controlled Trials

“…The mechanism of HIIT in blood pressure reduction may be related to nitric oxide (NO). Previous research demonstrated that high-intensity exercise can increase the blood flow velocity, resulting in increased NO production by vascular endothelial cells, further vasodilation of blood vessels, and lowered blood pressure (Ghardashi Afousi et al, 2018;Izadi et al, 2018). Furthermore, HIIT could increase the shear stress of the vascular endothelium, reduce sympathetic nerve activity and peripheral blood vessel resistance, and lower blood pressure (Nishida et al, 1992;Halliwill, 2001;Green et al, 2004;Pal et al, 2013;Sawyer et al, 2016).…”

The effect of acute aerobic exercise on central arterial stiffness, wave reflections, and hemodynamics in adults with diabetes: A randomized cross-over design

“…A bout of HIIE induced greater antegrade shear stress on the cardiovascular system when compared to MICE. 21 This can be attributed to the superior improvements found in vascular function following HIIE, 21 which could lead to changes in central arterial stiffness, wave reflections, and hemodynamics. Because there is sparse evidence on the effect of HIIE on the aforementioned outcomes, this is an area where investigation in needed since HIIE could play a role in the management in these cardiovascular anomalies.…”

Low-to-Moderate-Intensity Resistance Exercise Is More Effective than High-Intensity at Improving Endothelial Function in Adults: A Systematic Review and Meta-Analysis

“…These results are different from the aerobic exercise interventions. In aerobic exercise trials, increased exercise intensity is reported to have greater beneficial effects on EF [ 13 , 21 , 22 , 23 ]. A meta-analysis also reported a significant dose-response relation between aerobic exercise intensity and FMD [ 22 ].…”

“…Aerobic exercise training is an effective evidence-based strategy to reduce CVD risk factors, possibly by promoting EF and arterial stiffness. Several studies have confirmed the efficacy of aerobic exercise in improving the EF in healthy young adults [ 8 , 9 , 10 ], older adults [ 11 , 12 , 13 ], and unhealthy men [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. It is further emphasized that the greater beneficial effects of exercise intervention on EF are associated with exercise modalities and intensity [ 13 , 21 , 22 , 23 ].…”

“…Several studies have confirmed the efficacy of aerobic exercise in improving the EF in healthy young adults [ 8 , 9 , 10 ], older adults [ 11 , 12 , 13 ], and unhealthy men [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. It is further emphasized that the greater beneficial effects of exercise intervention on EF are associated with exercise modalities and intensity [ 13 , 21 , 22 , 23 ]. However, the effect of resistance exercise (RE) on EF is yet to be elucidated.…”