Acute exercise and impaired glucose tolerance in obese humans

Background: Individuals with impaired glucose tolerance (IGT) have a greater risk of developing diabetes and cardiovascular disease compared to those with normal glycaemic control. The aim of this study was to examine the effects of acute aerobic exercise on glycaemia, regional arterial stiffness and oxidative stress in obese subjects with IGT. Design: Twelve obese subjects (7 males and 5 females; 48.0 ± 9.4 yrs; BMI 32.4 ± 7.0 kg/m2) with IGT participated in a 30 minute bout of walking at 65% of maximum predicted heart rate (HR). Pulse wave velocity (PWV, for determination of arterial stiffness) and blood pressure (BP) were examined pre and post exercise, while venous blood samples were drawn for determination of glucose, blood lipids and indices of oxidative stress and inflammation (lipid hydroperoxides – LOOH; superoxide dismutase – SOD; hs-CRP – high sensitivity C-reactive protein). Results: Post exercise PWV (9.1 ± 1.2 m/sec vs. 8.6 ± 1.0 m/sec), glucose (5.7 ± 0.6 mmol∙L-1 vs. 5.4 ± 0.6 mmol∙L-1) and diastolic BP (94 ± 14 mmHg vs. 86 ± 13 mmHg) decreased, respectively (P <0.05). A correlation was observed between PWV and glucose (r = 0.544, P <0.05). There were no changes in LOOHs, SOD, hs-CRP or blood lipids, respectively (P > 0.05). Conclusions: These findings suggest that acute aerobic exercise can reduce regional arterial stiffness in obese subjects with IGT by possibly improving glucose metabolism, independent of changes in oxidative stress.