RESUMO
Objective To explore the effect and possible mechanism of 12 weeks of progressively resistive exercises on the autonomic nervous function of patients with type 2 diabetes mellitus ( T2DM) fasting and after an oral glucose tolerance test ( OGTT) . Methods Fifty T2DM patients were randomly divided into an exercise group ( E, n=30) and a control group ( C, n=20) . Group E performed progressively resistive exercises for 12 weeks, while group C maintained their normal lifestyle. Blood glucose, insulin, glycosylated hemoglobin, an insulin resist-ance index ( IRI) , heart rate variability, blood pressure variability and baroreflex sensitivity were measured after fasting and after an OGTT before and after the intervention. Results After the intervention, in the fasting state and after an OGTT, all of group E's glycemic control variables except insulin levels were significantly lower than be-fore the intervention ( P≤0.05) . No significant changes were observed in the autonomic nervous function parame-ters. However, after the intervention total power (LnTP), a comprehensive indicator of autonomic nervous system activity, normalized low frequency power (LFn), LnLF/high frequency power (LnLR/HF) and the low-frequency component of systolic blood pressure (LFSBP) increased significantly after OGTT in group E (P≤0.05), while there were no significant changes in the control group. Moreover, after the intervention there were no significant differences between the two groups in the indicators of autonomic nervous system functioning after fasting, but the LnTP, LFn, LnLF/HF and LFSBP2 of group E were significantly higher than those of group C after an OGTT (P≤0.05). In addition, the △LnLF/HF of group E was negatively correlated with △IRI (r=-0.469, P≤0.05). Conclusions Twelve weeks of progressively resistive exercises has no effect on autonomic nervous functioning after fasting for patients with T2DM, but it improves sympathetic neural responses after an OGTT. This may be related to its ameliorating insulin resistance.