Impact of acute high-intensity interval exercise on plasma pentraxin 3 and endothelial function in obese individuals-a pilot study.

PURPOSE: Pentraxin 3 (PTX3) has been shown to be a predictor of endothelial dysfunction in patients with increased risk of cardiovascular disease (CVD) (e.g., obesity). Circulating PTX3 concentrations are dysregulated in obese individuals and are elevated following acute aerobic exercise. High-intensity interval exercise (HIIE) has been demonstrated to be as effective as continuous moderate-intensity exercise in improving endothelial function, as indicated by brachial artery flow-mediated dilation (BAFMD), in patients with CVD. Therefore, the purpose of this study was to examine the effect of acute HIIE on plasma PTX3 and BAFMD responses in obese individuals. METHODS: Eight obese and six normal-weight young males participated in acute HIIE (4 intervals of 4 min at 80-90% of VO2max; 3 min of active recovery at 50-60% VO2max). Plasma PTX3 and BAFMD were measured prior to, immediately following exercise, and one and 2 hours into recovery. RESULTS: Plasma PTX3 concentrations significantly increased following HIIE, yet the PTX3 response to HIIE was significantly blunted in obese compared to normal-weight participants. While the kinetic responses of BAFMD were also significantly different in obese compared to normal-weight participants, similar increases above the baseline were observed 2 hours into recovery in both groups. Finally, plasma PTX3 concentrations were not associated with BAFMD at baseline or in response to HIIE. CONCLUSION: The utilization of HIIE may serve as a time-efficient exercise prescription strategy to transiently improve endothelial function, independent of elevated plasma PTX3 concentrations, in obese individuals.

The Impact of Obesity on C1q/TNF-Related Protein-9 Expression and Endothelial Function following Acute High-Intensity Interval Exercise vs. Continuous Moderate-Intensity Exercise.

C1q-TNF-related protein-9 (CTRP9) increases endothelial nitric oxide synthase and reduces vasoconstrictors. There is limited information regarding exercise-mediated CTRP9 in obesity. The purpose of this study was to compare high-intensity interval exercise (HIIE) and continuous moderate-intensity exercise (CME) on the CTRP9 response and an indicator of endothelial function (FMD) in obese participants. Sixteen young male participants (9 obese and 7 normal-weight) participated in a counterbalanced and caloric equated experiment: HIIE (30 min, 4 intervals of 4 min at 80-90% of VO2 max with 3 min rest between intervals) and CME (38 min at 50-60% VO2 max). Serum CTRP9 and FMD were measured prior to, immediately following exercise, and 1 h and 2 h into recovery. CTRP9 was significantly increased immediately following acute HIIE and CME in both groups (p = 0.003). There was a greater CME-induced FMD response at 2 h into recovery in obese participants (p = 0.009). A positive correlation between CTRP9 and FMD percent change was observed in response to acute CME when combined with both obese and normal-weight participants (r = 0.589, p = 0.016). The novel results from this study provide a foundation for additional examination of the mechanisms of exercise-mediated CTRP9 on endothelial function in individuals with obesity.