F-14 Thematic Poster - Obesity and the Cardiovascular System Friday, May 30, 2014, 1:00 PM - 3:00 PM Room: 102 A
BACKGROUND: Exercise can improve endothelial function but the cellular and molecular mechanisms, and influence of different exercise intensities, are not clear. There is also evidence of sex differences in endothelial responses to exercise. Endothelial microparticles (EMPs) have emerged as a potential biomarker of endothelial damage and activation.
PURPOSE: To compare continuous vigorous-intensity exercise (CVI) to high-intensity interval exercise (HII) on circulating EMPs in men and women.
METHODS: Six males (BMI = 30 ± 3, VO2peak = 29 ± 8 ml.kg-1.min-1, 25 ± 6 yr) and seven females (BMI = 28 ± 2, VO2peak = 28 ± 4 ml.kg-1.min-1, 21 ± 3 yr) participated in three experimental trials in a randomized counterbalanced crossover design: 1) No exercise control (CTL); 2) CVI (20 min @ just above ventilatory threshold); 3) HII (10 X 1-min @ ~90% peak aerobic power). Exercise conditions were matched for work and diet was controlled post-exercise. Fasting blood samples were obtained ~18 hr after each condition. CD62E+ and CD31+/CD42b- EMPs were assessed in platelet poor plasma by flow cytometry.
RESULTS: There was a significant Sex X Exercise interaction for both CD62E+ and CD31+/CD42b- EMPs (P < 0.05). In males, both CVI and HII resulted in reduced CD62E+ EMPs compared to CTL (P ≤ 0.05). In females, CVI resulted in higher CD62E+ EMPs (P < 0.05 vs CTL) whereas HII showed no change. In males, both CVI and HII resulted in reduced CD31+/CD42b- EMPs (P < 0.05 vs. CTL) with the reduction being greater in CVI compared to HII (p < 0.05). CD31+/CD42b- EMPs were unchanged in females.
CONCLUSIONS: A single bout of both CVI and HII reduce circulating CD62E+ and CD31+/CD42b- EMPs measured on the morning following exercise in males. In females, the only difference noted was an increase in CD62E+ EMPs on the morning following CVI. Circulating EMPs appear to be highly responsive to acute bouts of high-intensity exercise in young, overweight/obese males. Future research is needed to investigate mechanisms responsible for differential EMP responses to exercise between males and females.
Supported by Natural Sciences and Engineering Research Council (NSERC) of Canada, UBC Okanagan Internal Grant, USF World