Effect of Exercise Training on Glucose Effectiveness Assessed by 2-compartment labelled minimal moelel

点击翻译按钮获取中文摘要

Glucose itself can enhance glucose disposal and suppress production independent of a change in insulin. Although literature abounds with reports of effect of exercise on insulin sensitivity (SI), there is a paucity of literature relating to the effect of physical exercise on glucose effectiveness. We have studied pathogenesis of glucose intolerance and beneficial effects of exercise on glucose effectiveness (SG) by minimal model approach, which is a mathematical model to analyze time course of glucose and insulin during intravenous glucose tolerance test. Although there was a heterogeneity in SI and pancreatic insulin secretion in subjects with impaired-glucose tolerance (IGT) and non insulin dependent diabetes mellitus (NIDDM), at least one of the two is reduced resulting in reduced insulin action. Decreased SG was common hi IGT and NIDDM subjects regardless of their insulin sensitivity index. Furthermore, adopting stable-labeled glucose enabled us to isolate peripheral component of SI (SI^<2*>) and SG (SG^<2*>) and both indexes are enhanced in endurance trained subjects. Endogenous glucose production (EGP) of NIDDM patients was suppressed but it was less than that of controls suggesting that hepatic glucose effectiveness specific to suppressing EGP is decreased in NIDDM. In endurance trained athletes, EGP at basal condition was enhanced, is suppressed similarly during the first 30 min of IVGTT, recovered faster and overshot greater than those of control subjects. SG^<2*> and basal EGP positively correlate. The higher basal EGP and greater EGP-overshoot of endurance trained athletes function to compensate for the higher peripheral glucose demand in order to maintain glucose homeostasis.