Grant: CIHR Fellowship

Spinal cord injury (SCI) is a devastating condition that critically impairs the nervous system's regulation of the heart and blood vessels. Individuals with higher-level injuries (i.e. the midback or higher) live with a number of adverse cardiovascular complications, including frequent episodes of excessively low and high blood pressure (called orthostatic hypotension and autonomic dysreflexia, respectively), all of which drastically impact the individual's quality of life and likely predisopose them to future cardiovascular complications or disease. To that point, cardiovascular disease has been identified as a leading cause of death in individuals with SCI, who have 3-5 fold greater odds of heart disease compared to able-bodied individuals. Recently, our group completed a large-scale review and found that individuals with SCI have much smaller hearts and notable changes in heart function; yet, of the data available, only 5% represented females with SCI. In Canada, females comprise over 25% of the SCI population, as such it is clear that females are largely underrepresented in SCI research to date. So far, researchers have characterized key differences between the male and female hearts in healthy, able-bodied populations; yet, whether such sex differences exist in the SCI population is not known. What's more, we currently do not know whether the frequency or intensity of extreme blood pressure swings (i.e. orthostatic hypotension, autonomic dysreflexia) differs in females versus males with SCI, and how SCI impacts the heart's ability to respond to daily physiological stressors, like changing posture. Therefore, the primary objective of this work is to assess the impacts of high-level SCI on sex differences in the heart's function and structure i) at rest and ii) in response to orthostatic (postural) stress. The secondary objective is to assess the frequency and intensity of extreme blood pressure swings in females and males with SCI.