Microparticles (MPs) are shed extracellular vesicles that express the pro-thrombotic tissue factor (TF). Aerobic exercise may reduce MP count and TF expression. This study investigated the impact of acute running or rest followed by standardised meal consumption on MP phenotypes and TF expression.
15 males (age: 22.9 ± 3.3 years; body mass: 81.9 ± 11.4 kg; V[Combining Dot Above]O2 max 54.9 ± 6.5 mL·kg·min-1; mean ± SD) completed 1h of running (70% V[Combining Dot Above]O2max) or rest at 9am, and consumed a standardised meal (1170 kcal, 43% CHO, 17% PRO, 40% fat) at 10:45am. Venous blood samples were taken at 9am, 10am and 11:30am. MP concentration, diameter, phenotypes and TF-expression were assessed using nanoparticle tracking analysis (NTA) and flow cytometry.
NTA identified no changes in MP concentration or diameter in response to time or trial. Flow cytometry revealed total MP count increased from 9am to 10am (1.62 ± 2.28 to 1.74 ± 2.61 x1010/L, p = .016, effect size (η2) = .105), but was unaffected by trial. TF+ platelet-derived MP % reduced from 9am to 10am (44.0 ± 21.2 to 21.5 ± 9.3%, p = .001, η2 = .582) after exercise only (control: 36.8 ± 18.2 to 34.9 ± 11.9%, p = .972). TF+ neutrophil-derived MP % reduced from 9am to 11:30am (42.3 ± 17.2 to 25.1 ± 14.9%, p = 0.048, η2 = .801) in the exercise trial only (control: 28.5 ± 15.7 to 32.2 ± 9.6%, p = .508).
Running induced a significant reduction in %TF+ platelet and neutrophil MP, suggesting a transient reduction in cardiovascular risk via reduced TF-stimulated thrombosis. This requires further investigation over longer time periods in cardiovascular disease populations.
1School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom;
2Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom;
3Leicester School of Allied Health Sciences, Faculty of Health and Life Sciences, De Montfort University, Leicester, United Kingdom;
4University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom
Corresponding author: Nicolette C Bishop, School of Sport, Exercise and Health Sciences, Loughborough University, LE11 3TU. N.C.Bishop@lboro.ac.uk
This research was supported by the NIHR Leicester Biomedical Research Centre. Current affiliation for Patrick Highton: Collaborations for Leadership in Applied Health and Research Care (CLAHRC) within the Diabetes Research Centre, University of Leicester, Leicester, United Kingdom. The authors declare no conflict of interest. The results of this study are presented clearly, honestly, and without fabrication, falsification or inappropriate data manipulation. The results of the study do not constitute an endorsement by the American College of Sports Medicine.
Accepted for publication: 13 March 2019.