The purpose of this study was to compare the pattern of blood pressure (pressor) response to isometric handgrip contractions between older and younger males with and without blood occlusion. Ten older males (mean age 54.7 +/- 3.0 yrs) and ten younger males (mean age 26.6 +/- 1.9 yrs) normotensive at rest and dynamic exercise participated in this study. Following the determination of their maximum voluntary contraction (MVC), subjects performed handgrip contractions (dominant) at 20%, 40%, and 60% MVC (for 30 seconds), and at MVC (for 12 seconds), with and without blood occlusion. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and heart rate (HR) responses were recorded at every 5 seconds for the 20%, 40%, and 60% MVC, and at every 2 seconds during the MVC test using a Finapres BP monitor. Results indicated that without blood occlusion the mean absolute SBP, DBP, and MAP to isometric handgrip contractions were significantly higher in the older males than in the younger males for all contraction intensities although the mean absolute HR at all intensities was significantly lower in the older males. With blood occlusion, the mean absolute SBP was also significantly higher for all contraction intensities in the older males; mean absolute DBP was significantly higher in the older males only at MVC and mean absolute MAP was significantly higher in the older males except at 60% MVC. Mean absolute HR was again significantly lower in the older males during blood occlusion. However, there were no significant differences with and without blood occlusion between the two age groups in the slopes of SBP, DBP, MAP, and HR responses to the isometric contractions except for DBP at 60% MVC with blood occlusion, which was higher in the younger males. Within the younger age group, the mean absolute SBP was significantly greater with blood occlusion than without blood occlusion at 20% and 40% MVC, but similar at F 60% MVC and at MVC; mean absolute DBP and MAP were significantly higher with blood occlusion than without blood occlusion at 20%, 40%, and 60% MVC but not at MVC. Mean absolute HR was similar between blood occlusion and no blood occlusion for all contraction intensities. Within the older age group, there were no significant differences between with and without blood occlusion for mean absolute SBP, DBP, MAP, and HR responses to isometric handgrip contractions. It is concluded that although absolute pressor response to isometric handgrip contractions is higher in older males, the pattern of pressor response to isometric handgrip contractions is similar between the two age groups. Blood occlusion during isometric handgrip contractions did not influence the pressor response of older males. However, blood occlusion increased in the pressor response of younger males at lower percentages of MVC.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/10555 |
| Date | January 1993 |
| Creators | Lin, Yun. |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 83 p. |
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