Exercise-Induced Improvement in Vasodilatory Function Accompanies Increased Insulin Sensitivity in Obesity and Type 2 Diabetes Mellitus

Abstract

Because vasodilatory dysfunction has been postulated to contribute to insulin resistance, the exercise-induced improvement in vasodilatory function may signify changes in the endothelium that could contribute to the improvement in insulin sensitivity observed after aerobic exercise training.

Vascular reactivity at rest and during exercise in middle-aged obese men: effects of short-term, low-intensity, exercise training

“…Indeed, in obese adults, acetylcholine-stimulated vasodilation was improved after a 10% weight loss induced by diet plus exercise, 39 whereas no significant weight loss was obtained in our study. However, De Filippis et al 4 reported improved vasodilatory response to acetylcholine after an 8-week training program, without any weight change. Their training program at high intensity induced a 27% increase in VO 2 peak, which was greater than the 8% obtained with our lower intensity training program.…”

“…Our result, obtained non-invasively, confirmed several previous pharmacological studies demonstrating blunted agonist-mediated vasodilation in obese subjects. 1,4 Measurement of muscle perfusion and vascular conductance during isolated exercise also provided a good estimate of vasodilatory responsiveness of resistance vessels within working muscles. 14 One major result from the present study was that, irrespective of exercise intensity, obese men exhibited lower BF and vascular conductance than their normal-weight counterparts during a local knee-extensor exercise.…”

“…2,3 Endothelial dysfunction has also been demonstrated in obese subjects, involving both conduit and resistance arteries. 4,5 Conduit artery function can be readily evaluated by brachial artery flow-mediated dilation (FMD), 6 whereas resistance artery function is usually evaluated via pharmacological approaches. Each method has been used in obese subjects among whom lower FMD 5,[7][8][9] and lower blood flow (BF) responses to vasodilatator substances have been reported.…”

“…Exercise training brings well-known metabolic and cardiovascular benefits 17 and is recommended in the management of obesity. Although exercise training improves endothelial function in obese adults by means of the FMD method 18,19 or acetylcholine-responses, 4 its effects on vascular function during exercise remain unclear. The few published data have shown increased forearm vascular conductance during mild to moderate handgrip isometric exercise in obese women after weight loss resulting from a diet and training program intervention.…”

Does physical activity reduce the risk of cardiovascular disease in overweight and obese individuals?

“…To avoid confounding from the most recent exercise bout, the measurements were Table 1. Health benefits of exercise for overweight and obese persons, independent of changes in body g g weight or body fat p p Glucose metabolism and insulin action Decreased fasting glucose [10] Decreased fasting insulin [7,8,10,11•,19] Increased glucose tolerance [11•,12,16] Increased insulin sensitivity [7-10,11•,12-23,24••,25] Decreased HbA 1c [9] Blood Pressures Decreased resting SBP [9,10,15,[27][28][29][30] Decreased resting DBP [9,10,15,[27][28][29][30] Decreased ambulatory BP [29] Lipids and lipoproteins Decreased cholesterol [14,16,31] Decreased LDL-cholesterol [14,31] Increased HDL-cholesterol [10,23,29,32] Decreased triglycerides [9,10,16,23,29,32] Improved LDL and HDL Subfractions [32] Endothelial function Increased vascular dilatory function [14,35••,36,37] Hemostasis Increased t-PA release capacity [35••] Decreased platelet reactivity [38,39] Enhanced fibrinolysis [38,39] Decreased plasminogen activator inhibitor-1 …”