Associations Between Habitual Sedentary Behavior and Endothelial Cell Health

Endothelial dysfunction is a mechanism that may explain the link between prolonged sedentary time and cardiovascular disease. However, the relation between habitual sedentary behavior (SED) and endothelial function has yet to be explored.

The purpose of this study was to examine the association of accelerometer-measured SED with markers of endothelial cell health.

Healthy adult participants (n=83; 43.4% male; 25.5 ± 5.8 years old) were examined. SED was measured for 7-days by accelerometer. Endothelial function measures included endothelium-dependent vasodilation (EDV); endothelial microparticles (EMPs) [CD62E+ and CD31+/CD42- EMPs]; and endothelial progenitor cells (EPCs) [CD34+/CD133+/KDR+ and CD34+/KDR+EPCs]. Participants were classified as having low or high SED based on a median split.

Participants in the low and high SED group spent a mean ± SD of 8.6 ± 1.1 and 11.1 ± 1.0 h/day in SED, respectively. No significant differences between the low and high SED groups were detected in mean [95% confidence interval (CI)] EDV (2.51 [2.21-2.81] vs. 2.36 [2.07-2.64], p=0.50), EMPs (CD62E+: 6.70 [6.55-6.84] vs. 6.56 [6.42-6.69], p=0.20; CD31+/CD42‒: 6.26 [6.10-6.42] vs. 6.18 [6.03-6.33], p=0.50), or EPCs (CD34+/KDR+: 11.91 [9.23-14.48]×10^-2 vs. 14.87 [12.41-17.32]×10^-2, p=0.13); CD34+/CD133+/KDR+: 1.84 [1.28-2.39]×10^-2 vs. 2.17 [1.64-2.70]×10^-2, p=0.43).

Among healthy adults, habitual SED was not associated with markers of endothelial cell health.