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Improved brachial artery shear patterns and increased flow‐mediated dilatation after low‐volume high‐intensity interval training in type 2 diabetes
Author(s) -
Ghardashi Afousi Alireza,
Izadi Mohammad Reza,
Rakhshan Kamran,
Mafi Farnoosh,
Biglari Soheil,
Gandomkar Bagheri Habiballah
Publication year - 2018
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/ep087005
Subject(s) - medicine , brachial artery , cardiology , type 2 diabetes , hemodynamics , blood flow , intensity (physics) , diabetes mellitus , high intensity interval training , blood pressure , endocrinology , physics , quantum mechanics
New FindingsWhat is the central question of this study ? Can low‐volume high‐intensity interval training and continuous moderate‐intensity exercise modulate oscillatory and retrograde shear, blood flow and flow‐mediated arterial dilatation in patients with type 2 diabetes?What is the main finding and its importance ? Low‐volume high‐intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow‐mediated dilatation and outward arterial remodelling in patients with 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 max ) and 2 min at 55–60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max 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.