Effect of Prolonged Sitting and Breaks in Sitting Time on Endothelial Function
dc.contributor.author | Thosar, Saurabh S. | |
dc.contributor.author | Bielko, Sylvanna L. | |
dc.contributor.author | Mather, Kieren J. | |
dc.contributor.author | Johnston, Jeanne D. | |
dc.contributor.author | Wallace, Janet P. | |
dc.contributor.department | Department of Medicine, IU School of Medicine | en_US |
dc.date.accessioned | 2016-01-04T18:45:52Z | |
dc.date.available | 2016-01-04T18:45:52Z | |
dc.date.issued | 2015-04 | |
dc.description.abstract | Sitting time (ST) is associated with cardiovascular disease risk factors, whereas breaking ST has been reported to be beneficial for reducing cardiovascular risk. Purpose: The objective of this study is to examine the effects of breaking ST on superficial femoral artery (SFA) endothelial function. Hypotheses: 1) Prolonged sitting would induce endothelial dysfunction and changes in shear forces, and 2) breaking ST with brief periods of activity would prevent attenuation in endothelial function. Methods: Twelve nonobese men (24.2 ± 4.2 yr) participated in two randomized 3-h sitting trials. In the sitting (SIT) trial, subjects were seated on a firmly cushioned chair for 3 h without moving their lower extremities. In the breaking ST trial (ACT), subjects sat similar to the SIT trial but walked on a treadmill for 5 min at 2 mph at 30 min, 1 h 30 min, and 2 h 30 min during the sitting interval. SFA flow-mediated dilation (FMD) was assessed at baseline, 1 h, 2 h, and 3 h in each trial. Statistical analyses were performed using dependent variables SFA FMD and shear rates. Significance was set at P ≤ 0.05. Results: In the SIT trial, there was a significant decline in SFA FMD from baseline to 3 h (baseline, 4.72% ± 3.78%; 1 h, 0.52% ± 0.85%; 2 h, 1.66% ± 1.11%; 3 h, 2.2% ± 2.15; P < 0.05 by ANOVA) accompanied by a decline in mean shear rate and antegrade shear rate but no difference in shear rate (area under the curve). By two-way repeated-measures ANOVA, ACT prevented the sitting-induced decline in FMD (baseline, 4.5% ± 2.3%; 1 h, 5.04% ± 2.85%; 2 h, 5.28% ± 5.05%; 3 h, 6.9% ± 4.5%) along with no decline in shear rates. Conclusion: Three hours of sitting resulted in a significant impairment in shear rate and SFA FMD. When light activity breaks were introduced hourly during sitting, the decline in FMD was prevented. | en_US |
dc.eprint.version | Author's manuscript | en_US |
dc.identifier.citation | Thosar, S. S., Bielko, S. L., Mather, K. J., Johnston, J. D., & Wallace, J. P. (2015). Effect of prolonged sitting and breaks in sitting time on endothelial function. Medicine and Science in Sports and Exercise, 47(4), 843–849. http://doi.org/10.1249/MSS.0000000000000479 | en_US |
dc.identifier.uri | https://hdl.handle.net/1805/7875 | |
dc.language.iso | en_US | en_US |
dc.publisher | Lippincott Williams & Wilkins | en_US |
dc.relation.isversionof | 10.1249/MSS.0000000000000479 | en_US |
dc.relation.journal | Medicine and Science in Sports and Exercise | en_US |
dc.rights | Publisher Policy | en_US |
dc.source | Author | en_US |
dc.subject | sedentary activity | en_US |
dc.subject | flow mediated dilation | en_US |
dc.subject | intermitent activity | en_US |
dc.title | Effect of Prolonged Sitting and Breaks in Sitting Time on Endothelial Function | en_US |
dc.type | Article | en_US |