This is a series of three experiments with brachial artery flow-mediated dilation (BAFMD) as the major outcome variable. The first study examined the temporal response of the brachial artery diameter following forearm occlusion in sixteen young (28±8 years) and fifteen older (85±8 years) men. Following release of the pressure cuff there is a significant reduction in brachial diameter compared to baseline, followed by a rapid increase to a PEAK. When comparing the magnitude of the decrease in diameter and the BAFMD between Young and Old, older subjects demonstrated a blunted response. A significant relation was noted between the magnitude of decrease and BAFMD (r=- 0.44, p= 0.04). Specific features of the biphasic pattern are blunted in older adults compared with younger subjects. The magnitude of the drop in diameter following forearm occlusion correlates with the magnitude of the BAFMD.
The second study examined the relation between BAFMD and the total score from the Continuous Scale Physical Function Performance Test (PFP-10). Sixty-four men (84±11years) were studied. BAFMD was associated with the total PFP-10 score (r = 0.45, p = 0.0001) and age (r = -0.36, p = 0.003). When individuals were categorized based on their PFP-10 score, those in the highest functional class, exhibited the highest BAFMD, compared to those in the middle class, who had greater vasoreactivity than those in the lowest functional class.
The final study examined the effects of four weeks of unilateral handgrip exercise training on BAFMD and the features of the vasoreactivity curve. Twelve men (81±5 years) were studied before, during and after four weeks of handgrip training of the non-dominant arm. Following training, a 40% increase in BAFMD was observed in the trained arm only. Significant improvements in BAFMD were observed after the second week of training (p=0.024). Also, BAFMD was significantly related to the estimated shear rate (r=0.341, p<0.001). A biphasic pattern was not observed in the present study. A significant improvement in BAFMD was observed following unilateral handgrip training. These improvements take place very rapidly and may be partly mediated through increases in shear stress resulting from changes in resistance vessel function.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-07102007-114010 |
| Date | 10 July 2007 |
| Creators | Dobrosielski, Devon |
| Contributors | Maria Kosma, Kevin Macaluso, Michael Welsch, Arnold Nelson, Laura Stewart |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-07102007-114010/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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