Associations Of Objectively Measured Sedentary Time With Endothelial Function Biomarkers In Young Male Adults

Abstract

PURPOSE: Sedentary behavior (SB) is recognized as a serious global health issue. SB-induced down regulation of shear rate and blood flow play a key role in the pathogenesis of endothelial dysfunction, an important prognostic marker for cardiovascular disease. The purpose of this study was to assess the association between objectively measured sedentary time and endothelial function biomarkers in young male adults. METHODS: A total of 93 participants (age, 21.8 ± 3.8 yr; body height, 171.6 ± 6.4 cm; body weight, 62.1 ± 6.4 kg; % body fat, 15.6 ± 4.6%; body mass index (BMI) 21.1 ± 1.7 kg/m2; waist circumference 74.5 ± 5.1 cm; heart rate (HR) 67.6 ± 9.5 bpm; systolic blood pressure (SBP) 108.4 ± 9.1 mmHg; diastolic blood pressure (DBP) 71.6 ± 8.1 mmHg) wore the activPALTM continuously for 7 days without removal. Total sedentary time was assessed using PALanalysis v8.0. Bedtime and wake-up time were recorded by participants. Sleep duration was determined as the time between bed time and wake-up time. Sedentary time during waking hours was calculated as the total sitting/lying time minus sleep duration. A fasting venous blood sample was drawn from each of the participants from which serum endothelial cell adhesion molecules E-selection, P-selectin, Intercellular Adhesion Molecule 1 (ICAM-1) and Vascular Cellular Adhesion Molecule 1 (VCAM-1) were measured using flow cytometry. Multiple linear regression models examined the associations of sedentary time with endothelial function biomarkers using SPSS version 23.0. RESULTS: E-selectin (β = 0.226, 95% confidence interval [CI]: 0.021, 0.431) and P-selectin (β = 0.216, 95% CI:0.017, 0.415) were positively associated with sedentary time after controlling for age and BMI. After moderate-to -vigorous physical activity (MVPA) was added to the model, there were no significant association between E-selectin and sedentary time. No significant associations were found between ICAM-1 or VCAM-1 with sedentary time or between ICAM-1 or VCAM-1 with sedentary time after controlling age, BMI, and MVPA. CONCLUSIONS: Objectively measured sedentary time was positively associated with E-selectin and P-selectin in young male adults independent of age and BMI. MVPA may alleviate the adverse effects of sedentary time on biomarkers of endothelial function.