Affiliation:
1. School of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, QLD 4102, Australia
2. School of Population Health, University of Queensland, Princess Alexandra Hospital, Brisbane, QLD 4102, Australia
3. School of Human Movement Studies, University of Queensland, Brisbane, QLD 4072, Australia
Abstract
The aim of the present study was to determine the effects of a 4-week exercise training intervention on blood glucose, insulin sensitivity, BMI (body mass index) and cardiorespiratory fitness in patients with Type 2 diabetes, and to identify and establish criteria for patients who are more likely to improve their blood glucose from short-term exercise training. A randomized, controlled trial of exercise training, comprising two supervised and one non-supervised sessions of individualized cardiorespiratory and resistance exercise per week, was performed in 132 healthy patients with Type 2 diabetes (exercise training group, n=68), with the aim of accumulating a minimum of 150 min of moderate-intensity exercise for 4 weeks. BMI, waist circumference, blood pressure, blood lipid profile, blood glucose, insulin, insulin sensitivity [calculated by HOMAIR (homoeostasis model assessment of insulin resistance) and QUICKI (quantitative insulin check index)], β-cell function (calculated by HOMAβ-Cell), HbA1c (glycated haemoglobin) and V̇O2max (maximal oxygen consumption) were measured at baseline and at 4 weeks. The exercise training group had significant improvements in V̇O2max, BMI and triacylglycerols (triglycerides). There were no significant changes in blood glucose, HOMAIR, QUICKI or HOMAβ-Cell. Decreases in blood glucose were significantly predicted by baseline blood glucose and HbA1c, with these variables accounting for 15.9% of the change in blood glucose (P<0.001). ROC (receiver operator characteristic) curve analysis revealed that patients with a blood glucose >8.85 mmol/l (sensitivity=73%, specificity=78%) and HbA1c >7.15% (sensitivity=79%, specificity=60%) were more likely to achieve a clinically significant decrease in blood glucose. In conclusion, in apparently healthy patients with Type 2 diabetes, a 4-week exercise intervention improved cardiorespiratory fitness, BMI and triacylglycerols. Elevated blood glucose and HbA1c predicted improvements in blood glucose.