Microvascular and macrovascular dysfunction plays an important role in the pathogenesis of diabetic vascular disease. Twenty-nine older patients with type 2 diabetes were randomly assigned into the land-based (LB; n = 14) or water-based (WB; n = 15) groups. Both groups completed supervised aerobic cycling exercises three times per week for 12 weeks. The WB group performed cycling exercise training in warm water (36 °C) immersed to the hip level. After 12 weeks, blood glucose concentration and insulin resistance did not change but hemoglobin A1c levels decreased (P < .05) in both groups. Plasma nitric oxide concentrations increased (P < .05) in both groups. Flow-mediated dilation in the popliteal artery increased and arterial stiffness decreased (P < .05) in both exercise groups. Indices of microvascular reactivity improved (P < .05) only in the WB group. The benefits of warm water-based training were similar in general, and superior in some measures, to the more established land-based cycling exercise.
Saowaluck Suntraluck, Hirofumi Tanaka and Daroonwan Suksom
Napasakorn Chuensiri, Hirofumi Tanaka and Daroonwan Suksom
To determine the acute effects of high-intensity intermittent exercise (HIIE) on vascular function.
Lean (n = 18, BMI = 17.1 ± 0.7) and obese (n = 17, BMI = 25.4 ± 0.8) prepubescent boys aged 10.2 ± 0.2 years were studied. HIIE consisted of 8 sets of 20 s of cycle ergometry at 100, 130, and 170% of VO2peak alternating with 10 s of rests.
The obese group had higher (p < .05) body mass, BMI, body fat percentage, waist-hip ratio than the lean group. Carotid artery wall thickness and arterial stiffness as assessed by brachial-ankle pulse wave velocity (baPWV) were greater in the obese than in the lean group (p < .05). Brachial artery flow-mediated dilation (FMD) was not different between the groups. Total energy expenditure increased gradually as the exercise intensity increased in both groups (p < .05). The obese group had significantly greater total energy expenditure in all three HIIE intensities than the lean group. FMD tended to be higher and baPWV lower as the exercise intensity increased in both groups. Only the HIIE at 170% demonstrated greater FMD compared with the baseline in both groups. baPWV decreased significantly after HIIE at 130 and 170% VO2peak in both groups.
Supramaximal HIIE can be a feasible exercise modality for improving vascular function in obese prepubescent boys. Future exercise intervention studies are warranted.