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Impact of an acute bout of submaximal aerobic exercise on circulating leukocytes in individuals with spinal cord injury

University of British Columbia

Experiencing a spinal cord injury (SCI) can be a traumatic and permanently life altering event. The inability to transmit neural impulses through the spinal cord to organs and tissues leads to widespread systemic impairments in sensory/motor, cardiovascular, endocrine and immune function. Exercise is generally known to lead to improvements in cardiometabolic measures such as obesity, cardiovascular function, and the promotion of a more anti-inflammatory cellular environment. The transient leukocytosis observed during acute exercise is indicative of immune function, contributing to long term immunomodulatory and anti-inflammatory changes resulting from chronic exercise. Though an abundance of able-bodied exercise leukocytosis literature exists, comprehensive leukocyte measures in response to acute exercise for individuals with SCI are limited. Eight healthy, recreationally active adults with stable SCI (> 1 year) with injury below C3 were recruited to determine whether 30 minutes of submaximal aerobic exercise at 60% peak power output (PPO), in line with the updated SCI exercise guidelines, would lead to increases in circulating leukocytes. In a randomized crossover design, participants completed an exercise condition and a time-matched seated control condition separated by 7 days. Participants exercised for 30 minutes with blood draws at baseline, after 30 minutes of exercise, and 90 minutes after exercise. Blood draws during the seated control condition were taken at the same time points (baseline, 30 minutes, 120 minutes). Cells were quantified using multi-colour flow cytometry and analyzed using a linear mixed model. Significant increases (condition X time interactions, P ≤ 0.05) were observed for total CD3+ lymphocytes (19%), CD4+ T helper lymphocytes (16%), CD8+ T cytotoxic lymphocytes (24%), CD3+/CD56+ natural killer T (NKT) lymphocytes (31%), and CD56+ natural killer (NK) lymphocytes (63%) following 30 minutes of exercise. No changes were observed following exercise in CD19+ B lymphocytes, CD14+ classical monocytes, CD14+/CD16+ intermediate monocytes, CD16+ neutrophils or total CD45+ leukocytes. CD16+/CD14dim non-classical monocytes decreased significantly 90 minutes after exercise by 27%. In conclusion, these preliminary data suggest that 30 minutes of acute submaximal aerobic exercise at 60% PPO is sufficient to increase most lymphocyte populations immediately following exercise yet is insufficient at inducing a general leukocytosis in individuals with SCI.

Text

2020-07-15

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/75171

Health and Exercise Sciences

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/