• Cardiovascular and Cognitive Adaptations Following Isometric Handgrip Exercise Training in Hypertensive Adults

      Dempster, Kylie Samantha; Applied Health Sciences Program
      Isometric handgrip (IHG) exercise training is an effective method of blood pressure (BP) reduction in clinical and non-clinical populations. The efficacy of IHG on cardiovagal baroreflex sensitivity (cvBRS) and systemic arterial stiffness (i.e. carotid-toe pulse wave velocity (ctPWV)) is less well understood, especially in hypertensive populations who demonstrate increased arterial stiffness and decreased BRS. Furthermore, hypertension is considered an accelerated model of cognitive decline, often attributed to the effects of increased BP and arterial stiffness. This study utilized IHG (n=8) and CON groups (n=4) to examine the effects of 8-weeks of IHG training or no IHG training on arterial stiffness, cvBRS, and cognitive function in hypertensive adults. Significant group differences in SBP and ctPWV change was observed (p<0.05) indicating that IHG training reduced SBP and systemic arterial stiffness compared to no IHG training. Moreover, although not significant (p>0.05), the IHG group demonstrated an ~53% increase in BRS. Lastly, a significant difference in Trail Making Test Part A (TMT-A) time (p<0.001) was observed in the IHG group, suggesting that IHG training improved motor, and visual control and speed. These findings suggest that IHG training can improve systemic arterial stiffness and possibly cvBRS in a hypertensive population, in addition to the new potential for improving specific aspects of cognitive function.
    • The Influence of Sex on the Relationship Between Arterial Mechanical Properties and Cardiovagal Baroreflex Sensitivity

      Klassen, Stephen; Applied Health Sciences Program
      Cardiovagal baroreflex sensitivity (cvBRS) demonstrates a strong relationship with arterial mechanical properties. Both cvBRS and arterial mechanics differ by sex such that males demonstrate greater cvBRS, yet lower large artery elasticity than females. Whether the relationship between cvBRS and arterial mechanics is similar in males and females remains unexamined. As a result, it is unclear whether arterial mechanics contribute to sex differences in cvBRS. This study investigated the cross-sectional relationship between cvBRS and arterial mechanical properties of the common carotid, carotid sinus and aortic arch (AA) in 36 (18 females) young, healthy normotensives. The cvBRS-arterial mechanics relationship did not reach statistical significance and did not differ by sex. Both cvBRS and AA distensibility were greater in females than males. Sex differences in cvBRS were eliminated after controlling for AA distensibility. These findings suggest that in this sample, AA elasticity may contribute to the greater cvBRS in females than males.