Are twenty-four sessions of aerobic exercise sufficient for improving cardiac parameters in diabetes mellitus? A randomized controlled trial

Background: Diabetes is a chronic disease that reduces cardiorespiratory fitness and increases systolic and diastolic blood pressures as well as resting heart rate due to the activity level of the sympathetic nervous system. The aim of this study was to assess the effectiveness of 2 types of aerobic exercise, with and without external loading, on cardiac parameters in diabetic patients. Methods: This randomized controlled trial was carried out on 45 volunteers. These individuals were randomly divided into aerobic, weighted vest, and control groups. The aerobic protocol comprised 24 sessions of aerobic exercise. The exercise program for the weighted vest group was identical to that of the aerobic group, except that the subjects wore a weighted vest. The parameters were measured before and after the 24 sessions. Results: The mean age of the study population was 48.30 ± 5.02 years in the aerobic group, 48.33 ± 5.74 years in the weighted vest group, and 48.60 ± 4.79 years in the control group. Males comprised 7 (53.8%) patients in the aerobic group, 7 (58.3%) in the weighted vest group, and 8 (53.3%) in the control group. After 8 weeks, maximum oxygen consumption in the aerobic group (mean ± SD = 37.54 ± 8.02 mL/kg/min, 95% CI: 5.48 to 11.60; p value < 0.001) and the weighted vest group (mean ± SD = 35.92 ± 3.96 mL/kg/min, 95% CI: 4.36 to 9.64; p value < 0.001) was increased, similar to metabolic equivalent of task in the aerobic group (mean ± SD = 11.60 ± 1.62 kcal/kg × h, 95% CI: 1.48 to 2.72; p value < 0.001) and the weighted vest group (mean ± SD = 11.21 ± 1.11 kcal/kg × h, 95% CI: 1.23 to 2.28; p value < 0.001). Furthermore, resting heart rate decreased significantly in the aerobic group (mean ± SD = 90.23 ± 8.90 bpm, 95% CI:-13.93 to-1.29; p value = 0.022) and the weighted vest group (mean ± SD = 90.58 ± 9.19 bpm, 95% CI:-0.16 to-12.33; p value = 0.045). Conclusion: These findings suggest that 24 aerobic exercise sessions might improve cardiac parameters in type 2 diabetes.