Effect of an acute bout of exercise on glucose disposal in human obesity

Abstract

The effect of acute exercise on insulin action has been studied in six obese (150-250% ideal body weight) non-insulin-dependent diabetics (OD), seven obese normoglycemics (ON), and six lean healthy controls (LC). Using a three-stage euglycemic clamp, the metabolic clearance rate (MCR) of glucose under increasing insulin concentrations was measured. The insulin dose-response curve was assessed on two separate occasions: 1) a base-line test and 2) 1 h after aerobic treadmill exercise at a steady-state heart rate of 150-160 beats/min. In the base-line test, under all insulin levels, glucose MCR was significantly lower in obese compared with lean individuals (P less than 0.01). Exercise increased glucose MCR at the highest hormonal concentrations applied to 124 and 134% of base line in OD and in ON, respectively (P less than 0.05); the insulin concentration required for one-half of the maximal clearance rate of glucose achieved in this study decreased from 200 to 130 and from 160 to 95 microU/ml in OD and ON, respectively (P less than 0.05). The changes in these parameters were insignificant in LC. It is suggested that acute exercise affected the insulin dose-response curve in OD and in ON but not in LC; although enhanced by exercise, glucose MCR remained significantly lower in both obese groups compared with control subjects. We concluded that insulin resistance, which accompanies extreme obesity, could be markedly decreased but not completely reversed by one bout of exercise.

Dysregulation of muscle glycogen synthase in recovery from exercise in type 2 diabetes

“…An enhanced post-exercise insulin sensitivity has been demonstrated both for glucose-tolerant individuals and for various insulin-resistant populations, including patients with type 2 diabetes, with the change mainly accounted for by an increase in NOGD [11][12][13]. As glycogen synthesis is the primary pathway of NOGD [1], these changes favour glycogen replenishment after exercise [13,17,[35][36][37].…”

Is weight loss the optimal target for obesity-related cardiovascular disease risk reduction?

“…For instance, insulin resistance is known to improve by approximately 20% after 1 h of aerobic exercise in healthy (35,36), insulin-resistant (37) and diabetic subjects (36,38) -improvements that are equivalent in magnitude to those achieved through chronic pharmacological intervention (39,40). The augmented insulin sensitivity is apparent immediately after exercise (36) and persists for 20 h to 48 h thereafter (35,37,38). It is also well established that a single bout of aerobic exercise results in 10% to 25% reductions in triglycerides (TGs) and 7% to 15% increases in high-density lipoprotein (HDL) cholesterol levels (11,(41)(42)(43).…”

Combining short-term metformin treatment and one bout of exercise does not increase insulin action in insulin-resistant individuals

“…A single bout of exercise dramatically enhances insulinstimulated glucose uptake in individuals who are insulin resistant (4,11), an effect that lasts for 3-72 h postexercise (27). The mechanisms by which exercise enhances whole body insulin sensitivity are multifactorial and likely involve alterations in enzymes regulating nonoxidative glucose disposal (2), decreased muscle glycogen (6), and increased skeletal muscle blood flow (9).…”