Impact of reduced daily physical activity on conduit artery flow-mediated dilation and circulating endothelial microparticles

• Published in: Journal of applied physiology (1985) Vol. 115; no. 10; pp. 1519 - 1525
• Main Authors: Boyle, Leryn J., Credeur, Daniel P., Jenkins, Nathan T., Padilla, Jaume, Leidy, Heather J., Thyfault, John P., Fadel, Paul J.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 15.11.2013
• Subjects: Adult; Apoptosis; Biomarkers - blood; Blood; Blood Flow Velocity; Brachial Artery - diagnostic imaging; Brachial Artery - physiopathology; Cardiovascular disease; Cardiovascular diseases; Cell-Derived Microparticles - metabolism; Cell-Derived Microparticles - pathology; E-Selectin - blood; Endothelial Cells - metabolism; Endothelial Cells - pathology; Exercise; Humans; Hyperemia - physiopathology; Male; Phenotype; Plasma; Platelet Endothelial Cell Adhesion Molecule-1 - blood; Platelet Glycoprotein GPIb-IX Complex - metabolism; Popliteal Artery - diagnostic imaging; Popliteal Artery - physiopathology; Regional Blood Flow; Risk Factors; Sedentary Lifestyle; Time Factors; Ultrasonography, Doppler; Vasodilation; Veins & arteries; Young Adult; atherosclerosis; endothelial function; physical inactivity; sedentary
• ISSN: 8750-7587; 1522-1601; 1522-1601
• DOI: 10.1152/japplphysiol.00837.2013

Physical inactivity promotes the development of cardiovascular diseases. However, few data exist examining the vascular consequences of short-term reductions in daily physical activity. Thus we tested the hypothesis that popliteal and brachial artery flow-mediated dilation (FMD) would be reduced and concentrations of endothelial microparticles (EMPs) would be elevated following reduced daily physical activity. To examine this, popliteal and brachial artery FMD and plasma levels of EMPs suggestive of apoptotic and activated endothelial cells (CD31 + /CD42b − and CD62E + EMPs, respectively) were measured at baseline and during days 1, 3, and 5 of reduced daily physical activity in 11 recreationally active men (25 ± 2 yr). Subjects were instructed to reduce daily physical activity by taking <5,000 steps/day and refraining from planned exercise. Popliteal artery FMD decreased with reduced activity (baseline: 4.7 ± 0.98%, reduced activity day 5: 1.72 ± 0.68%, P < 0.05), whereas brachial artery FMD was unchanged. In contrast, baseline (pre-FMD) popliteal artery diameter did not change, whereas brachial artery diameter decreased (baseline: 4.35 ± 0.12, reduced activity day 5: 4.12 ± 0.11 P < 0.05) following 5 days of reduced daily physical activity. CD31 + /CD42b − EMPs were significantly elevated with reduced activity (baseline: 17.6 ± 9.4, reduced activity day 5: 104.1 ± 43.1 per μl plasma, P < 0.05), whereas CD62E + EMPs were unaltered. Collectively, our results provide evidence for the early and robust deleterious impact of reduced daily activity on vascular function and highlight the vulnerability of the vasculature to a sedentary lifestyle.