The Impact of Obesity on Endothelial Function Following Maximal Aerobic Exercise

Obesity is associated with increased arterial stiffness and endothelial dysfunction, leading to inflammation and oxidative stress. This study aimed to investigate the effects of maximal aerobic exercise on indicators of endothelial function (C1q-TNF-related-protein-9 [CTRP9], total nitric oxide [NOx], and flow-mediated dilation [FMD]) in obese and normal-weight individuals. Twenty young male participants (11 obese and 9 normal weight) participated in a maximal graded treadmill exercise test. The serum levels of CTRP9 and NOx and FMD were measured prior to, immediately following exercise, and 1 and 2 hours into recovery. There was a significant time effect for serum CTRP9 (p=0.049) with a decrease from immediately post exercise to 1 hour after exercise mainly driven by the normal-weight group (p=0.007), followed by a return to the baseline levels at 2 hours into recovery. A significant time effect for serum NOx was also observed following exercise (p=0.033) with an increase mainly driven by the obese group from baseline to immediately after exercise (p=0.006) that returned to baseline level during recovery. No change was found in FMD in both groups following exercise (p=0.452), although obese participants had lower FMD compared to normal-weight participants across time (p=0.017). These findings suggest that maximal aerobic exercise elicits a transient alteration in biomarkers of endothelial function (NOx and CTRP9), independent of obesity status. Therefore, the novel results from this study may indicate that obesity does not impact the acute endothelial response to maximal aerobic exercise.