Effects of combined training with different intensities on cardiac structure and function in patients with type 2 diabetes: a randomised controlled trial

Abstract

Background Regular exercise is a well-accepted strategy to improve cardiovascular system function in patients with type 2 diabetes mellitus. The results of trials assessing the impact of exercise training on cardiac function in T2DM have been inconsistent. Whether combined exercise training improve subclinical cardiac dysfunction in people with T2DM, however, is not known. Therefore, the purpose of this study was to investigate the effects of high-intensity interval training (HIIT) combined with resistance training (RT) and moderate-intensity continuous training (MICT) combined with RT on cardiac structure and function in patients with type 2 diabetes. The impact of HIIT + RT and MICT + RT on cardiorespiratory fitness and metabolic control was also investigated. Methods 54 patients who met the inclusion criteria were randomly assigned to the HIIT + RT group, MICT + RT group, and control group (CG). With 18 participants in each group, for 12 weeks, three times per week exercise intervention. Patients underwent echocardiographic cardiac function and structure, metabolic and clinical evaluation at baseline and 3 months. Results (1) There was a significant difference between groups for changes on VO2peak. Greater increases on VO2peak were achieved for HIIT + RT in comparison to CG group, with significant difference between HIIT + RT and MICT + RT. VO2peak significantly increased for both HIIT + RT and MICT + RT (P༜0.01). (2) After 12 weeks of intervention, HIIT + RT significantly changed EF, LVPWT, LVEDD and LVESD and LVM (P༜0.01). MICT + RT only had significant effects on EF, LVPW (P༜0.01), and LVM (P༜0.05). Compared with CG, HIIT + RT significantly improve EF, LVEDD (P༜0.01), and LVM (P༜0.05) in T2DM patients. Compared with MICT + RT, HIIT + RT was more effective in improving LVEDD (P༜0.05). Conclusions (1) 12 weeks of HIIT + RT and MICT + RT significantly improved body weight and blood glucose control in T2DM patients, which would be beneficial to reduce the risk of cardiovascular disease in T2DM patients. (2) 12 weeks of HIIT + RT and MICT + RT significantly improved peak oxygen uptake and cardiac structure and function in T2DM patients; However, HIIT + RT was more effective in improving cardiopulmonary fitness and cardiac structure and function in T2DM patients.