Jinhee Woo

Antioxidant enzyme activities and DNA damage in children with type 1 diabetes mellitus after 12 weeks of exercise.

Objective:  The objectives of this study are to assess the effects of a low‐intensity exercise training which is not risky for children with type 1 diabetes mellitus (T1DM) on the antioxidant enzyme activities and oxidative stresses compared with healthy controls.

Exercise Training Improves Cardiac Autonomic Nervous System Activity in Type 1 Diabetic Children

[Purpose] We investigated the effect exercise training has on cardiac autonomic nervous system (ANS) and cardiovascular risk profiles in children with type 1 diabetes mellitus (DM). [Subjects] Fifteen type 1 DM children (all boys; 13.0±1.0 years of age) were enrolled in the study. [Methods] The subjects received exercise training three times a week in a 12-week program. Each child was asked to walk on a treadmill to achieve an exercise intensity of VO2max 60%. ANS activity was measured by power spectral analysis of the electrocardiogram (ECG). Blood samples were obtained for serum lipid profiles. To evaluate Doppler-shifted Fourier pulsatility index (PI) analysis, a 5-MHz continuous wave Doppler (VASCULAB D10) set was used to measure forward blood flow velocity (FLOW) in the radial artery. [Results] Total and low-frequency (LF) power of heart rate variability increased significantly after exercise intervention. Total cholesterol (TC) levels were significant lower after exercise intervention. Total and high-frequency (HF) power were significantly correlated with higher TC levels, but diastolic blood pressure and HF was significantly correlated with lower TC levels. [Conclusion] Regular exercise intervention should be prescribed for children with type 1 DM.

The effects of detraining and training on adipose tissue lipid droplet in obese mice after chronic high-fat diet

BackgroundIt is well known that exercise promotes lipolysis by stimulating the lipid droplet (LD) signaling pathway. However, few studies have been conducted to examine the effect of detraining with high fat diet (HFD) and training effects after long-term HFD. Here, we investigated the effect of detraining and training on adipose tissue LD pathway in diet-induced obese mice after continuous HFD.MethodsSeventy male C57BL/6 mice were randomly assigned into a Normal diet + Sedentary group (ND, n = 10) or a High-fat diet + Sedentary group (HF, n = 50); in the HF group, obesity was induced by a 45% fat chow for six weeks. For the subsequent eight weeks, the HF group was randomly subdivided into an HF (n = 30) or an HF + training group (HFT, n = 20), and the HFT group was subjected to treadmill training while on an HFD. Following this eight-week period, the HFT group stopped exercising (HFT-DT group, n = 10), and the mice in the HF group were randomly subdivided into an HF (n = 10) or an HF + training group (HF-T, n = 10). After training and detraining, abdominal visceral fat was obtained and analyzed by histological staining and western blot.ResultsTreadmill exercise decreased body weight and fat mass (P <0.05), and increased the levels of PKA, perilipin1, CGI-58, ATGL, and HSL (P <0.05) after eight weeks of training. Following eight weeks of detraining, the levels of PKA and HSL were decreased (P <0.05); however, exercise after chronic HFD increased the levels of PKA, perilipin1, CGI-58, ATGL, and HSL (P <0.05), and decreased body weight and fat mass (P <0.05).ConclusionsRegardless of dietary restrictions, exercise is an effective treatment for obesity, owing to the regulation of LD signaling proteins. Moreover, the effects of regular exercise after chronic HFD were similar to those of exercise in the absence of HFD. Therefore, although obesity is induced by chronic HFD, exercise without dietary change is sufficiently effective for obesity treatment regardless of the preceding HFD period.

Exercise and dietary change ameliorate high fat diet induced obesity and insulin resistance via mTOR signaling pathway

[Purpose] The purpose of this study was to investigate the effect of exercise and dietary change on obesity and insulin resistance and mTOR signaling protein levels in skeletal muscles of obese rats. [Methods] Sixty male Sprague-Dawley rats were divided into CO (Normal diet) and HF (High Fat diet) groups in order to induce obesity for 15 weeks. The rats were then subdivided into CO, COT (CO + Training), HF, HFT (HF + Training), HFND (Dietary change), and HFNDT (HFND + Training) groups (10 rats / group). The training groups underwent moderate-intensity treadmill exercise for 8 weeks, after which soleus muscles were excised and analyzed. Data was statistically analyzed by independent t-test and One-way ANOVA tests with a 0.05 significance level. [Results] Fasting blood glucose, plasma insulin, and HOMA-IR in the HF group were significantly higher, as compared with other groups (p <.05). Protein levels of insulin receptor subunit-1 (IRS-1), IRS-2, and p-Akt were significantly higher in the HFT, HFND, and HFNDT groups, as compared with HF group. In addition, the protein levels of the mammalian target of rapamycin complex 1 (mTORC1) and ribosomal S6 protein kinase 1 were significantly decreased by exercise and dietary change (p <.05). However, mTORC2 and phosphoinositide 3-kinase were significantly increased (p <.05). [Conclusion] In summary, despite the negative impact of continuous high fat intake, regular exercise and dietary change showed a positive effect on insulin resistance and mTOR signaling protein levels.

The effect of exercise on expression of myokine and angiogenesis mRNA in skeletal muscle of high fat diet induced obese rat.

[Purpose] The purpose of this study was to investigate the effect of regular treadmill exercise on the mRNA expressions of myokines and angiogenesis factors in the skeletal muscle of obese rats. [Methods] Thirty two male Sprague-Dawley rats (4weeks old) were divided into the CO (control) and HF (high fat diet) groups. Obesity was induced in the HF group by consumption of 45% high-fat diet for 15 weeks. These groups were further subdivided into training groups (COT and HFT); the training groups conducted moderate intensity treadmill training for 8 weeks. Soleus muscles were excised and analyzed by real-time quantitative PCR. [Results] mRNA expression of myokines, such as PGC-1α, IL-6, and IL-15, in the COT and HFT groups (which conducted regular exercise), were higher as compared with the CO and HF groups (p < 0.05). Also, the levels in the HF group were significantly lower when compared with CO group (p < 0.05). Expression of angiogenesis mRNA, namely mTOR, VEGF, and FLT1, were significantly lower in the HF group, as compared to the CO group (p < 0.05). In addition, COT group had a higher expression of mTORC1, mTORC2, VEGF and FLT mRNA, than the CO group (p < 0.05); the HFT group also had higher expressions of mTOR, VEGF and FLT1 mRNA than the HF group (p < 0.05). [Conclusion] These results indicate that mRNA expression of myokines was increased through the activity of muscle contraction, and it also promoted the mRNA expression of angiogenesis due to activation of mTOR. Thus, we conclude that not only under normal health conditions, but in obesity and excess nutritional circumstances also, regular exercise seems to act positively on the glycemic control and insulin sensitivity through the angiogenesis signaling pathway.

Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance.

[Purpose] This study was conducted to understand the impacts of BCAA (branched-chain amino acid) and glutamine supplementation on the degree of blood fatigue factor stimulation and cytokines along with performance of exercise at the maximal intensity. [Subjects] Five male juvenile elite rowing athletes participated in this study as the subjects; they took 3 tests and received placebo supplementation (PS), BCAA supplementation (BS), and glutamine supplementation (GS). [Methods] The exercise applied in the tests was 2,000 m of rowing at the maximal intensity using an indoor rowing machine, and blood samples were collected 3 times, while resting, at the end of exercise, and after 30 min of recovery, to analyze the blood fatigue factors (lactate, phosphorous, ammonia, creatine kinase (CK)) and blood cytokines (IL (interleukin)-6, 8, 15). [Results] The results of the analysis showed that the levels of blood phosphorous in the BS and GS groups at the recovery stage were decreased significantly compared with at the end of exercise, and the level of CK appeared lower in the GS group alone at recovery stage than at the end of exercise. The level of blood IL-15 in the PS and BS groups appeared higher at the end of exercise compared with the resting stage. [Conclusion] It seemed that glutamine supplementation had a positive effect on the decrease in fatigue factor stimulation at the recovery stage after maximal intensity exercise compared with supplementation with the placebo or BCAA. Besides, pre-exercise glutamine supplementation seemed to help enhance immune function and the defensive inflammatory reaction.

The Effects of Treadmill Training on Neurotrophins and Immediately Early Protein in Obese Rats

The purpose of this study was to investigate the biological effect of obesity-induced oxidative damage on neurogenesis and early protein expression. Obesity was induced I thirty 4-week old male Sprague-Dawley rats through a high fat diet for 15 weeks. After one week of environmental adaptation, the rats were divided into 2 groups: high fat diet sedentary group (HDS, n

The Effects of D-Ribose Supplementation on the Production of Blood Fatigue Factors after Maximal Intensity Exercise

The purpose of this study was to examine the effect of D-ribose supplementation on the changes of blood fatigue substances (lactate, ammonia, phosphate and hypoxanthine) after maximal exercise performance in college male students. The experimental trials of each subject were divided into the following conditions: placebo supplement trial and D-ribose supplement trial. The subjects exercised using a Concept II Indoor rowing ergometer for 2,000 m Single Skull event. The subjects ingested 200 mg/kg of D-ribose after breakfast, lunch, dinner, as well as thirty minutes before exercising, for six days. Blood fatigue substances were continuously measured before exercise, immediately after exercise, and thirty minutes after exercise. The results indicated a significant difference in blood phosphate and hypoxanthine levels between the two experimental trials in the 30 minute recovery period (p

The Effects of Regulatory Exercise on Adipokines and Inflammatory Reaction in Type 1 Diabetic and Obese Children

The purpose of this study was to investigate the effects of aerobic exercise on adipokines and inflammatory reaction in obesity and type 1 diabetes mellitus (T1DM) children. We studied obese (OG, n

Effects of 12 Week Regular Aerobic Exercise on ST-segment and QTc Interval in Type 2 Diabetes Mellitus Patients

The purpose of the present study was to examine effect of 12 week regular aerobic exercise on ST-segment and QTc interval in middle age type 2 diabetes mellitus (T2DM) patients. The subjects consist of 13 type 2 diabetes mellitus (T2DM) patients in middle age men and all of them had no other complications. Subjects participated in aerobic exercise training for 12 weeks. They started to exercise for min at of , (exercise intensity has been increased gradually) per day, times a week. The results were compared before and after. Weight and BMI, % body fat, fasting glucose, HOMA-IR, were significantly decreased and , , exercisre time were significantly increased after 12 week aerobic exercise. Also, QTc interval and ST-segment were significantly decreased during at rest, peak exercise after 12 week aerobic exercise. Conclusionally, 12 week aerobic exercise may be improvement in decreased cardiovascular mortality factors (ST-segment) and abnormal autonomic dysfunction (QTc interval) and potentially increased exercise capacity.