Abstract
3078
Background: Acute coronary syndrome (ACS) patients were randomized post PCI to high intensity interval training (HIIT) versus moderate continuous training (MICT. Bio-energetic transfer analysis of oxygen supply to myocytic mitochondria was compared. Materials and Methods: All patients (25) were randomized for three months, 10 to HIIT and 15 to MICT. Baseline and follow-up measures of endothelial reactivity (RUR) and of mitochondrial uptake (PSSR) were taken according to the protocol already published (JACC, 2004). The measurements are based upon the intrinsic properties of 99mTctetrofosmin (Myoview ©) commonly used as a biomarker of mitochondrial dependent myocytic uptake. Two parameters linked to energy supply were retained: VO2max and HOMA (Homeostatic Model Assessment), a measure of Insulin resistance.
Results: A step by step regression analysis was done first with VO2max on RUR; then RUR on PSSR and finally of PSSR as a function of HOMA. The MICT group shows a correlation at baseline that increases after three months in all three instances. After HIIT training appears to promote RUR, PSSR and HOMA in a similar way except for HOMA.
Conclusions: The training protocol appears as the main source of mitochondrial response between these `energy supply` variables, be it RUR responding to VO2max, PSSR to RUR and HOMA to PSSR. With regards to the direction of this influence we are led to believe that myocyte mitochondrial bioenergetic activity observed by PSSR would influence the insulin resistance observed by HOMA as a function of slope changes in the regression. The bioenergetic activity observed by the mitochondria (PSSR) shows that its influence on insulin resistance eventually adapts to the regulation of exercise whatever the type of training, but this phenomenon is more demonstrative for the HIIT training. The adaptation of VO2max increases regardless of the type of training but this phenomenon is more demonstrative for the continuous training. There is necessarily a strong link between oxygen supply and bioenergy needs. Progressive training, better control of risk factors and completing an adaptation of interval training would be a better choice.