Ghardashi Afousi Alireza, Izadi Mohammad Reza, Rakhshan Kamran, Mafi Farnoosh, Biglari Soheil, Gandomkar Bagheri Habiballah
Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences, University of Tehran, Tehran, IR Iran.
Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences, University of Shahid Chamran, Ahvaz, IR Iran.
Exp Physiol. 2018 Sep;103(9):1264-1276. doi: 10.1113/EP087005. Epub 2018 Jul 22.
What 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.
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.
本研究的核心问题是什么？低容量高强度间歇训练和持续中等强度运动能否调节2型糖尿病患者的振荡性和逆行性剪切力、血流以及血流介导的动脉扩张？主要发现及其重要性是什么？低容量高强度间歇训练通过增加顺行性剪切力、降低逆行性剪切力和振荡指数，可增加一氧化氮生成，从而导致2型糖尿病患者的血流介导的扩张增加和动脉向外重塑。
2型糖尿病患者的动脉粥样硬化特征为内皮功能障碍，伴有血流介导的扩张（FMD）受损以及逆行性和振荡性剪切力增加。本研究调查了2型糖尿病患者在进行12周低容量高强度间歇训练（LV-HIIT）或持续中等强度训练（CMIT）前后基线和随访时的内皮依赖性血管舒张和剪切速率。75名久坐不动的2型糖尿病患者以及未经治疗的高血压前期或I期高血压患者被随机分为LV-HIIT组、CMIT组和对照组。LV-HIIT组的干预方案为以最大心率（HR）的85-90%进行12次1.5分钟的间歇训练，以及以HR的55-60%进行2分钟的训练。CMIT组的干预方案为在12周内每周进行3次、每次42分钟、以HR的70%进行的运动。使用高分辨率多普勒超声测量FMD、动脉直径、顺行性和逆行性血流以及剪切速率模式。LV-HIIT组肱动脉FMD显著增加（基线时为3.83±1.13，随访时为7.39±3.6%），而CMIT组与对照组（基线时为3.16±0.78，随访时为4.04±1.28%）相比无显著增加（基线时为3.45±0.97，随访时为4.81±2.36%）（P<0.05）。LV-HIIT组的逆行性剪切力显著降低（P<0.05），CMIT组的逆行性剪切力未见显著降低。LV-HIIT后的顺行性剪切力显著增加（P<0.05），而CMIT组则无变化。然而，两个运动组的振荡剪切指数均显著降低（P=0.029）。两个运动组的亚硝酸盐/硝酸盐（NOx）水平均升高，但LV-HIIT组升高幅度更大（P<0.001）。结果表明，通过增加NOx，HIIT可降低振荡性剪切力诱导的2型糖尿病患者FMD改善和动脉向外重塑。
