Effects of exercise intervention on vascular endothelium functions of patients with impaired glucose tolerance during prediabetes mellitus

Endothelial dysfunction (ED) is an early pathophysiological change in patients with impaired glucose tolerance (IGT) during prediabetes mellitus. This study was designed to test the hypothesis that exercise intervention contributes to the reversal of vascular endothelium-dependent dysfunction in middle-aged patients with IGT. Following exercise intervention, significant changes in endothelin (ET)-1, C-type natriuretic peptide (CNP), ΔDia-P, oral glucose tolerance test (OGTT)2h, fasting insulin, homeostasis model of assessment-insulin resistance (HOMA-IR), body fat percentage, waist circumference and waist to hip ratio were measured. However, no marked changes in carotid artery intima-media thickness (IMT), fasting blood glucose and BMI were observed following exercise intervention. Validity analysis of index changes in the two exercise intervention groups further confirmed there was no change. Exercise intervention increased CNP levels, decreased ET-1 levels and increased ΔDia-P, indicating improved vascular endothelium function. Decreased HOMA-IR following exercise suggests enhanced insulin sensitivity. Exercise intervention also improved glucose metabolism via decreased OGTT2h and fasting insulin. In addition, decreased waist circumference, ratio of waist to hip and body fat percentage following exercise intervention improved changes of body composition, including BMI, body fat and waist circumference. These results indicate that exercise intervention may reverse vascular endothelium-dependent dysfunction in middle-aged patients with IGT. This study also provided direct clinical data supporting the use of exercise intervention to prevent diabetes mellitus (DM) during the early stage.