BackgroundThere is controversy over whether aerobic or resistance exercise is more effective for improving endothelial function in type 2 diabetes mellitus (T2DM). This study was aimed to investigate the effects of an aerobic and resistance training program on endothelial function, and the influences of glycemic control, body weight changes, and aerobic capacity in T2DM.MethodsTotal 40 overweight women with T2DM were assigned into 3 groups: an aerobic exercise group (AEG, n=13), resistance exercise group (REG, n=12), and control group (CG, n=15), and followed either brisk walking for the AEG or resistance band training for the REG, 60 minutes per day, 5 days per week for 12 weeks with monitoring daily activity using accelerometers. We assessed endothelial function by flow-mediated dilation (FMD), and aerobic capacity by oxygen uptake at anaerobic threshold (AT_VO2) at baseline and following training program.ResultsThe mean participants' age was 57.0±6.8 years, and body mass index (BMI) was 27.0±2.3 kg/m2. After intervention, FMD increased by 2.2±1.9% in AEG, which differed from REG and CG (P=0.002), despite of decreased body weight (BW) in both AG and RG (2.8±2.5%, P=0.002; 1.6±2.0%, P=0.017, respectively). A significant increased AT_VO2 and decreased HbA1c were found only in AEG. In all participants, FMD was changed with the significant relations to the AT_VO2 (r=0.348, P=0.035), but not to HbA1c levels or BW.ConclusionAerobic exercise appears to be more beneficial than resistance exercise for improving endothelial function in T2DM. In addition, aerobic capacity could be a better predictor of changes in FMD than BW and glycemic control.

BackgroundOur goal was to investigate the effects of low intensity resistance training on body fat, muscle mass and strength, cardiovascular fitness, and insulin sensitivity in type 2 diabetes.MethodsTwenty-eight overweight women with type 2 diabetes were randomly assigned to a resistance training group (RG, n = 13) or a control group (CG, n = 15). RG performed resistance training using elastic bands, of which strength was equal to 40 to 50% of one repetition maximum (1RM), for three days per week. Each exercise consisted of three sets for 60 minutes. We assessed abdominal fat using computed tomography, muscle mass using dual-energy X-ray absorptiometry, and muscle strength using Keiser's chest and leg press. Insulin sensitivity was measured using the insulin tolerance test, and aerobic capacity was expressed as oxygen uptake at the anaerobic threshold (AT-VO2) before and after the 12-week exercise program.ResultsThe age of participants was 56.4 ± 7.1 years, duration of diabetes was 5.9 ± 5.5 years, and BMI was 27.4 ± 2.5 kg/m2, without significant differences between two groups. During intervention, a greater increase in muscle mass and greater decreases in both total fat mass and abdominal fat were observed in RG compared to those of CG (P = 0.015, P = 0.011, P = 0.010, respectively). Increase in 1RM of upper and lower extremities was observed in the RG (P = 0.004, P = 0.040, respectively), without changes in AT-VO2 and insulin resistance in either group.ConclusionIn conclusion, the low intensity resistance training was effective in increasing muscle mass and strength and reducing total fat mass without change of insulin sensitivity in type 2 diabetic patients.

BackgroundWe investigated the effects of exercise intensity on abdominal and mid-thigh adipose tissue, attenuation of skeletal muscle, and insulin sensitivity in overweight women with type 2 diabetes mellitus (T2DM).MethodsTwenty-eight patients were randomly assigned to control (CG, n=12), moderate intensity exercise (MEG, n=8), or vigorous intensity exercise (VEG, n=8) group. Subjects in both exercise groups completed a 12-week exercise program (MEG, 3.6 to 5.2 METs; VEG, ≥5.2 METs) that was monitored by accelerometers. We assessed body mass index (BMI), total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), mid-thigh intramuscular adipose tissue (TIMAT), total skeletal muscle (TTM), low density skeletal muscle (TLDM), and normal density skeletal muscle (TNDM) using computed tomography, and measured insulin sensitivity with an insulin tolerance test (KITT), before and after the intervention.ResultsAt baseline, the mean age was 53.8±7.9 years, duration of diabetes was 3.8±2.3 years, and BMI was 26.6±2.6 kg/m2. After 12 weeks, the percent change (%C) in BMI, TIMAT, and TLDM were not different among three groups. However, %C in TFA and VFA were significantly reduced in MEG compared to CG (P=0.026 and P=0.008, respectively). %C SFA was significantly reduced in VEG compared to CG (P=0.038) and %C TTM, TNDM, and KITT were significantly increased in VEG compared to the CG (P=0.044, P=0.007, and P=0.016, respectively).ConclusionAlthough there was no difference in the change in BMI among groups, TFA and VFA were more reduced in MEG, and only VEG increased TTM, TNDM, and insulin sensitivity compared to CG.

BackgroundThe typical Korean diet includes rice, which is usually served in a rice bowl. We investigated the effects of a meal plan using rice bowls of varying sizes on dietary energy intake (EI), body weight (BW), and blood glucose levels.MethodsForty-two obese women with type 2 diabetes mellitus were randomly assigned to use either a 200 mL small rice bowl (SB), a 380 mL regular rice bowl (RB), or to a control group (C). Both intervention groups were asked to reduce their EI by 500 kcal/day for 12 weeks and simple instructions for using the assigned bowl were provided. Dietary EI and proportion of macronutrients (PMN) were estimated from 3-day dietary records.ResultsReduction of EI was more prominent in the SB group compared to the RB and C group, although EI decreased significantly from baseline in all groups. Carbohydrate and fat intakes of the SB group were decreased greater than those of the RB and C group. However, changes in PMN were not significant across the 3 groups. Reduction of BW and HbA1c levels in the SB group was more prominent compared to the C group. Although, BW and HbA1c were decreased significantly from baseline in both bowl groups. There was no statistical difference between the two groups.ConclusionThe small rice bowl-based meal plan was effective at reducing EI, BW, and blood glucose levels, and the observed reductions in EI, carbohydrate, and fat intake were greater than those of the regular rice bowl-based meal plan.

BackgroundArterial stiffness is an important factor in atherosclerosis. Thus we examined whether aerobic exercise could reduce arterial stiffness in obese women with type 2 diabetes without diabetic complication.MethodsA total of 35 women with type 2 diabetes (body mass index, 26.6±2.8 kg/m2; age, 56.4±1.9 years; duration of diabetes, 4.7±4.8 years) were assigned to aerobic exercise group (AEG) or control group (CG). AEG completed a 12-week exercise program (3.6 to 5.2 metabolic equivalents, 3 day/week, 60 min/day), with their exercise activities monitored by accelerometers. We measured abdominal total fat area (TFA), visceral fat area (VFA), and subcutaneous fat area (SFA) by computed tomography, insulin sensitivity by insulin tolerance test (KITT), and augmentation index (AIx) by SphygmoCor at baseline and at the end of the 12-week program.ResultsThe AIx was improved in the AEG compared with the CG (P<0.001). The percent change of AIx had significant correlation with the improvement of physical activity energy expenditure (PAEE), aerobic capacity, TFA, and SFA (r=-0.416, P=0.013; r=0.560, P<0.001; r=0.489, P=0.003; r=0.531, P=0.001, respectively), but not with insulin sensitivity, energy intake, or VFA.ConclusionImprovement in aortic stiffness by aerobic exercise is related with the improvement of aerobic capacity, PAEE, and total fat but not with insulin sensitivity or energy intake in obese women with type 2 diabetes.