Doctor of Philosophy (PhD)
“Chronic disease will never reach its clinical horizon to compromise health if it is attacked at its origin” . Knowledge that one’s risk for cardiovascular events is related to the severity of endothelial dysfunction, and evidence that exercise training can improve endothelial function, has prompted speculation that measures of vascular function may serve as a “barometer” for cardiovascular health. This dissertation consists of three experiments intended to study vascular function and the manner in which it may influence or may be influenced by physical function. Project one examined the influence of high and low volume circuit weight training on forearm vascular function. Thirty-five individuals participated in a program consisting of 3 sessions/week for 5 weeks. Results indicated significant but similar strength gains in both groups (Hand Grip: Ä15.55%, Knee Extension: Ä21.00%, Bench Press: Ä35.31%; p<0.05). Reactive hyperemic responses, a measure of vascular function, only changed in those individuals with the lowest pre-training vascular measures, independent of group assignment. Project two examined the link between vascular and physical function in peripheral neuropathy patients. Reactive hyperemic responses were significantly related to the time up and go test (r=-0.31, p=0.02) and the 6-minute walk distance (r=0.37, p=0.007). These data suggest a link between measures of vascular and physical function in these patients, indicating that those with better vascular function have greater physical function. Project three examined the effects of an acute bout of exercise on nitric oxide, oxidative stress and anti-oxidants, and brachial vasoreactivity, before, at peak exercise, and in recovery, in trained individuals. The results indicated a significant increase in reactive oxygen species and peroxynitrite, and a decrease in the anti-oxidant glutathione peroxidase at peak exercise. Brachial vasoreactivity was significantly lower immediately after exercise, but returned to pre-exercise levels at 20 minutes into recovery. These findings suggest an acute bout of exercise contributes to a significant rise in oxidative stress, which can in part be buffered by anti-oxidants systems, but may cause temporary blunting of arterial reactivity. Collectively, these findings indicate the importance of examining vascular function, and its controllers, and may extend the current understanding of preserving and/or maintaining vascular health.
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Arce, Arturo, "Exercise and peripheral vascular function in health and disease" (2008). LSU Doctoral Dissertations. 72.
Michael A. Welsch