Differential impact of acute high-intensity exercise on circulating endothelial microparticles and insulin resistance between overweight/obese males and females

Abstract

Background: An acute bout of exercise can improve endothelial function and insulin sensitivity when measured on the day following exercise. Our aim was to compare acute high-intensity continuous exercise (HICE) to high-intensity interval exercise (HIIE) on circulating endothelial microparticles (EMPs) and insulin sensitivity in overweight/obese men and women.

Methods: Inactive males (BMI = 30 ± 3, 25 ± 6 yr, n = 6) and females (BMI = 28 ± 2, 21 ± 3 yr, n = 7) participated in three experimental trials in a randomized counterbalanced crossover design: 1) No exercise control (Control); 2) HICE (20 min cycling @ just above ventilatory threshold); 3) HIIE (10 X 1-min @ ∼ 90% peak aerobic power). Exercise conditions were matched for external work and diet was controlled post-exercise. Fasting blood samples were obtained ∼ 18 hr after each condition. CD62E(+) and CD31(+)/CD42b- EMPs were assessed by flow cytometry and insulin resistance (IR) was estimated by homeostasis model assessment (HOMA-IR).

Results: There was a significant sex X exercise interaction for CD62E(+) EMPs, CD31(+)/CD42b- EMPs, and HOMA-IR (all P < 0.05). In males, both HICE and HIIE reduced EMPs compared to Control (P ≤ 0.05). In females, HICE increased CD62E(+) EMPs (P < 0.05 vs. Control) whereas CD31(+)/CD42b- EMPs were unaltered by either exercise type. There was a significant increase in HOMA-IR in males but a decrease in females following HIIE compared to Control (P<0.05).

Conclusions: Overweight/obese males and females appear to respond differently to acute bouts of high-intensity exercise. A single session of HICE and HIIE reduced circulating EMPs measured on the morning following exercise in males but in females CD62E(+) EMPs were increased following HICE. Next day HOMA-IR paradoxically increased in males but was reduced in females following HIIE. Future research is needed to investigate mechanisms responsible for potential differential responses between males and females.

Fig 1. High-intensity exercise leads to sex specific changes in CD62E+ endothelial microparticles (EMPs).

A) Fasting CD62E+ EMPs in males in females in the no exercise control (Control) condition and ∼18 hr following high-intensity continuous exercise (HICE) or high-intensity interval exercise (HIIE). B) Individual values for each male and female participant are shown connected by a line. The Control condition is shown in the middle to illustrate the effect of HICE or HIIE. *P<0.05 males vs. females. #P<0.05 vs. Control within sex.

Fig 2. High-intensity exercise leads to sex specific changes in CD31+/CD42b- endothelial microparticles (EMPs).

A) Fasting CD31+/CD42b- EMPs in males and females in the no exercise control (Control) condition and ∼18 hr following high-intensity continuous exercise (HICE) or high-intensity interval exercise (HIIE). B) Individual values for each male and female participant are shown connected by a line. The Control condition is shown in the middle to illustrate the effect of HICE or HIIE. *P<0.05 males vs. females. #P<0.05 vs. Control within sex. &P<0.05 vs. HIIE within sex.

Fig 3. Relationships between endothelial microparticles (EMPs) measured in the sedentary Control condition and the changes seen after acute high-intensity exercise.

A) Significant negative correlations were found for baseline CD62E+ EMPs measured in the no exercise control (Control) condition and the reduction seen after acute high-intensity continuous training (HICE) and high-intensity interval training (HIIE) in males. B) A significant negative correlation was found for CD31+/CD42b- EMPs measured in the no exercise control (Control) condition and the reduction seen after HICE in males.

Fig 4. High-intensity exercise leads to sex specific changes in homeostasis model assessment of insulin resistance (HOMA-IR).

A) Fasting HOMA-IR in males in females in the no exercise control (Control) condition and ∼18 hr following high-intensity continuous training (HICE) or high-intensity interval training (HIIE). B) Individual values for each male and female participant are shown connected by a line. The Control condition is shown in the middle to illustrate the effect of HICE or HIIE. #P<0.05 vs. Control within sex. &P<0.05 vs. HICE within sex.