Hwi Ryun Kwon

The effects of resistance training on muscle and body fat mass and muscle strength in type 2 diabetic women.

Background Our 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. Methods Twenty-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 Keisers 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. Results The 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. Conclusion In 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.

Effects of Aerobic Exercise on Abdominal Fat, Thigh Muscle Mass and Muscle Strength in Type 2 Diabetic Subject

Background Aerobic exercise can effectively reduce visceral fat. However, few studies have examined the effect of daily physical activity on obesity and cardiopulmonary function in the subjects with diabetes. We examined the effect of moderate intensity of walking in obese diabetes patients by monitoring of daily activity and measuring the change in abdominal fat area, muscle are and maximal muscle strength. Methods We randomly assigned 27 obese women with type 2 diabetes to an aerobic exercise group (AG, n = 13) and control group (CG, n = 14). The AG performed moderate intensity walking for 60 minutes per exercise, 5 times per week, and for 12 weeks. The activity energy expenditure was monitored by a multi-record accelerometer. The CG maintained routine daily activities. At the time of the initiation of the study and after 12 weeks of exercise, the aerobic exercise capacity was assessed using oxygen consumption rate at anaerobic threshold (VO2-AT). The abdominal fat area and the quadriceps muscle area were measured by computed tomography, and the maximum muscle strength of the upper and lower limbs was measured by a chest press and a leg press, respectively. Results The mean age of the study subjects was 56.6 ± 8.0 years, the mean duration of diabetes was 6.3 ± 6.0 years, and the body weight index (BMI) was 27.3 ± 2.7 kg/m2. The BMI of the AG was significantly decreased (P = 0.003). In the AG, the visceral fat area and subcutaneous fat area were also significantly decreased (P = 0.018 and P < 0.001, respectively) but not in CG. VO2-AT of the AG was significantly improved, while that of the CG did not change (P = 0.009 and P = 0.115, respectively). The quadriceps muscle mass and the maximal muscle strength of the AG did not change, however, the CG showed a significant decrease. Duration of moderate intensity exercise was correlated with the decrease in total abdominal fat area (r = -0.484; P = 0.011) and that of high intensity exercise was correlated with improvement of cardiopulmonary function (r = 0.414; P = 0.032). Conclusion Daily moderate intensity aerobic exercise is effective at reducing abdominal fat mass, while high intensity exercise improves cardiopulmonary function.

Effects of Aerobic Exercise Intensity on Abdominal and Thigh Adipose Tissue and Skeletal Muscle Attenuation in Overweight Women with Type 2 Diabetes Mellitus

Background We 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). Methods Twenty-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. Results At 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). Conclusion Although 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.

The Correlations between Extremity Circumferences with Total and Regional Amounts of Skeletal Muscle and Muscle Strength in Obese Women with Type 2 Diabetes

Background Insulin resistance is related to central obesity and the amount of skeletal muscle. A simple and practical anthropometric marker for muscle mass is not known, although waist circumference (WC) is used as an indicator of abdominal obesity. The aims of this study were to investigate whether arm (AC) and thigh circumferences (TC) can be used as an indicator of muscle mass and if they are related to muscle strength. Methods A total of 110 obese (body mass index [BMI]≥25 kg/m2) women with type 2 diabetes were enrolled, and WC, AC, and TC were measured. Abdominal visceral fat (AVF), subcutaneous fat (ASF), and total fat (ATF) were assessed by computed tomography, regional muscle (MM), and fat mass by dual-energy X-ray absorptiometry, muscle strength by one repetition maximum (1RM) of both extremities (chest and leg press) and insulin resistance by KITT. Results The mean age was 56.2±7.3 years, duration of diabetes was 4.2±4.4 years, and BMI was 27.2±2.8 kg/m2. WC was correlated with ATF, AVF, and ASF (r=0.728, P<0.001; r=0.515, P<0.001; r=0.608, P<0.001, respectively). Arm MM was correlated with AC (r=0.500, P<0.001), and leg MM with TC (r=0.291, P=0.002). Upper 1RM was related to AC/WC ratio (r=0.359, P<0.001), and lower 1RM was to TC/WC ratio (r=0.286, P=0.003). Insulin resistance had significant relations with AVF, WC, and total MM (r=-0.262, P=0.008; r=-0.217, P=0.029; r=0.160, P=0.031, respectively). Conclusion The muscle mass was related to extremity circumferences, and muscle strength was to extremity/waist circumference ratio in obese women with type 2 diabetes.

The Small Rice Bowl-Based Meal Plan was Effective at Reducing Dietary Energy Intake, Body Weight, and Blood Glucose Levels in Korean Women with Type 2 Diabetes Mellitus.

Background The 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. Methods Forty-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. Results Reduction 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. Conclusion The 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.

The Usefulness of an Accelerometer for Monitoring Total Energy Expenditure and Its Clinical Application for Predicting Body Weight Changes in Type 2 Diabetic Korean Women

Background The purpose of this study was to evaluate the usefulness of an accelerometer in predicting body weight (BW) change during a lifestyle intervention and to find out whether exercise or overall physical activity is associated with change in insulin sensitivity and body composition. Methods A total of 49 overweight (body mass index [BMI] ≥ 23 kg/m2) women with diabetes were enrolled and performed lifestyle intervention while monitoring BW, total energy expenditure (TEE) and physical activity energy expenditure (PAEE) using an accelerometer, and energy intake (EI) using a three-day dietary record at baseline and every 2 weeks for 12 weeks. We assessed body composition using bioimpedance analysis and compared the actual BW change to the predicted BW change, which was calculated from the energy deficit (ED) between EI and TEE (ED = EI-TEE). Results Mean age was 57.2 years, duration of diabetes was 8.0 years, and BMI was 27.8 kg/m2. There was no significant difference between EI and TEE at baseline. For 12 weeks, the ED was 474.0 kcal·day-1, which was significantly correlated with BW change (-3.1 kg) (r = 0.725, P < 0.001). However, the actual BW change was 50% lower than the predicted BW change. Both TEE and PAEE correlated with change in KITT (r = 0.334, P = 0.019; r = 0.358, P = 0.012, respectively), BMI (r = -0.395, P = 0.005; r = -0.347, P = 0.015, respectively), and fat mass (r = -0.383, P = 0.007; r = -0.395, P = 0.005, respectively), but only TEE correlated with fat free mass change (r = -0.314, P = 0.030). Conclusion The accelerometer appears to be a useful tool for measuring TEE under free-living conditions for both short- and long-term periods.

Arterial Stiffness by Aerobic Exercise Is Related with Aerobic Capacity, Physical Activity Energy Expenditure and Total Fat but not with Insulin Sensitivity in Obese Female Patients with Type 2 Diabetes

Background Arterial 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. Methods A 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. Results The 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. Conclusion Improvement 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.