Exercise Intensity Reduces Circulating Annexin V- CD105 Microparticles in Adults With Prediabetes

Abstract

PURPOSE: Microparticles (MPs) derived from platelets, leukocytes and endothelial cells are important players in cardiovascular disease (CVD) risk. Exercise is established to reduce CVD risk, but no study has tested the effect of exercise intensity on various subtypes of MP in people with prediabetes. We tested the hypothesis that short-term interval (INT) training would reduce MP subtypes vs. continuous (CONT) exercise. METHODS: Eighteen obese adults (age: 63.8±1.5yrs BMI: 31.0±1.3 kg/m2) were screened for prediabetes using ADA criteria (75g OGTT and/or HbA1c). Subjects were randomized to INT (n=10, 3 min intervals at 90% and 50% HRpeak) or CONT (n=8, 70% HRpeak) training for 12 supervised sessions over 2 wks for 60 min/d. Fitness (VO2peak) and weight (kg) were assessed and arterial stiffness (augmentation index; AI) calculated using total AUC during a 75g OGTT. Total MPs, platelet MPs (CD31+/CD41+), endothelial MPs (CD105, CD31-/ CD41+) and leukocyte MPs (CD45+/CD41-) were analyzed from fresh plasma via imaging flow cytometry pre-/post- intervention. RESULTS: Our interventions had no effect on weight loss but INT exercise increased VO2peak (P=0.04) and reduced fasted AI (trend: P=0.08) compared with CONT training. While our intervention had no effect on platelet or leukocyte MPs, INT exercise decreased Annexin V- endothelial MP CD105 (1.6±0.2 vs. 1.4±0.2 count) compared with CONT training (1.2±0.2 vs. 1.8±0.1 count; P=0.04). Increased VO2peak correlated with decreased Annexin V+ CD105 endothelial MPs (r=-0.60, P=0.01). CONCLUSION: Exercise intensity decreases endothelial derived MPs through possibly a cardiovascular fitness related mechanism, independent of weight loss.