نشریه سوخت و ساز و فعالیت ورزشی
سال هفتم شماره 2 (پاییز و زمستان 1396)

Angiopoietin-like proteins that be involved in the regulation of lipid metabolism, can be potentially utilized in therapies for metabolic syndrome. The purpose of this study was to investigate the effect of eight weeks intermittent and continuous exercise training on serum angiopoietin-like protein 8 levels and lipid profile in 9-11 years old obese girls. Thirty students aged 9 to 11 years old with a percentile of body mass index more than 90% were randomly assigned to control (n = 9), continuous training (n = 11), and intermittent exercise (12). The exercises included eight weeks of continuous and intermittent walking (3 sessions per week). The subjects underwent continuous training in the first four weeks with 60-75% HRmax and in the second four weeks with of 70-75% HRmax, and subjects with intermittent exercises in the first four weeks with intensity of 75-80% HRmax and in the second four weeks with of 80-85% HRmax. Serum levels of ANGPTL8, HDL, LDL, TG, TC and glucose was measured in pre-test and post-test. The results of this study showed that in the intermittent group, ANGPTL8, TC, glucose increased (p< 0.05), and BMI and percentile of body mass index decreased (p<0.05). In the continuous group, the levels of ANGPTL8 and TC increased (p< 0.05) and BMI decreased (p<0.05). Comparison between groups showed that glucose and ANGPTL8 were not significantly different in two groups. The increased of angiopoietin-like protein 8 after eight weeks of continuous and intermittent exercises was independent of the type of exercise. It seems that, one of the main reasons  is the increase of glucose and TC, which suggests the therapeutic potential of angiopoietin-like protein 8 in reducing these factors by inhibiting it.

Although obesity is becoming epidemic all around the world, the effort to reduce its prevalence has not been effective. Thus, there is a need to find further paths to prevent obesity. The aim of this study was to determine the effect of endurance training and adenosine on the A1AR gene expression in the visceral adipose tissue of obese male rats Twenty wistar strain male rats were fed with high-fat food for twelve weeks and reached the average weight of 319+-30 grams. The rats were divided randomly into four groups after being conformed. The exercise training session included running on the treadmill with no slope for 12 week. Each week, five sessions were held for 15-31 minutes with the speed of 20-25 meters per minute. In order to measure the relative gene expression of A1AR, the PCR method was used. The data was analyzed using the statistical method of two-way analysis of variance. both variable of endurance training and adenosine consumption (independently) demonstrated a significant decrease in the A1AR gene expression in the visceral adipose tissue. (P=0.001). Also, the intraction of training and adenosine affects significant reduction of the A1AR expression. Endurance training and adenosine are strong stimulants of adipose tissue lipolysis as A1AR antagonists and have the potential to be used as effective lipolysis agents in obesity

Insulin resistance plays an important role in the development of abnormalities such as impaired glucose tolerance, type 2 diabetes, obesity, and hyperlipidemia. The discovery of protein tyrosine phosphatase 1b (PTP-1B) seems to be a milestone in the investigation of insulin signaling transmission. Thus the purpose of this study was to evaluate the effect of 6 weeks of high intensity interval training (HIIT) on expression of PTP-1B in the muscle tissue in type 2 diabetic rats.. In this study, 20, ten week old diabetic male rats were randomly divided into high intensity interval and control groups. The training group performed training protocol on a treadmill for 6 weeks and 5 session/week, with gradual increase in speed (25-35 m/min) during scheduled runs. Forty-eight hours after the last training session blood and tissue (from gastrocnemius) sampling were carried out in diabetic rats and PTP-1B gene expression was evaluated by Rea-Time PCR method. Data was analyzed using independent t-test and Shapiro Wilk at a significant level of p≤0/05. Findings show that PTP-1B was decreased in the diabetic rats of HIIT group but was not significant (P=0.432). Also, insulin resistance index and fasting glucose significantly were decreased in HIIT group (P=0.001), but serum insulin was increased (P=0.001). According to the results, it seems that HIIT does not affect PTP-1B gene expression, but it improves type 2 diabetes and insulin resistance.

Most studies have used moderate or low intensity endurance exercise to examine the effect of food intake with high and low glycemic index on metabolic responses and oxidation of substrates. However, the effect of glycemic index on high intensity intermittent exercise, which is a major characteristic of many sports, has not been studied. The purpose of the present study was to investigate the effect of high-glycemic (HGI) and low-glycemic (LGI)index isoenergetic breakfast on glucose homeostasis and substrate oxidation during high intensity intermittent exercise (HIIE). Eight male students with age 23.4 ± 0.9 years, weight 76/21± 4/38 kg, maximal oxygen uptake 53.7±1.0ml/kg/min, participated in two expermintal trials separated by 7 days. At each trial, 60 minutes after consumption isoenergitic breakfast (819 kcal), high intensity intermittent exercise (HIIE) was performed. Blood samples were evaluated for plasma glucose, insulin and glucagon, total fat and carbohydrate oxidation, evaluated by through respiratory equations. The results showed that in the postprandial period, increase in plasma glucose concentrations in HGI (from 86 to 127mg/dl) (P <0.05). In HGI, glucose concentration decreases rapidly in the early period of HIIE (to 79 mg/dl), but remains almost stable in LGI (P <0.05). AUG of glucose and insulin in HGI were higher (1.08%) than LGI (1.37%), respectively. The oxidation of fat during activity in LGI (2.5 g) was higher than that of HGI (3 g) (p <0.05). HGI causes hyperglycemia and hyperinsulinemia in the postprandial period, and higher levels of insulin before exercise can lead to a sudden drop in blood glucose over the course of the activity, but LGI, due to lower insulinemia, helps to maintain better blood glucose and glucose homeostasis during HIIE.

despite role of aerobic exercise training in controlling type 2 diabetes, effectiveness of different aerobic training intensity’s and their mechanism is unknown. Therefore, the aim of present study was to investigate the effect of eight weeks' low and moderate intensity aerobic training on levels of HbA1C, some hematological parameters and percent body fat in men with type 2 diabetes. subjects in present study was consist of 33 obese and overweight men with type 2 diabetes with average age of 43.2 ± 8.03 and BMI 28.63 ± 2.71 that randomly assigned in three groups (11 in each group) including control, low intensity aerobic exercise training and moderate intensity aerobic training. Low intensity aerobic training program were performed with 50 percent of maximum heart rate (MHR) and moderate intensity aerobic training with 70 percent of MHR. Training program continued for eight weeks and three sessions in week for 45-60 minutes in each session. results indicated that HbA1C, glucose and percent body fat significantly (p<0.05) decreased in both training groups. However, lipid profile significantly was improve only in moderate intensity aerobic training group. Moreover, HbA1C decrease and VO2peak increase in moderate intensity group was significantly diffrent to low intensity group. It seems that low intensity aerobic training in comparison to moderate intensity aerobic training are associated with lower adaptations and improvement in type 2 diabetes patient.

Derived hormones from adipokines are include leptin, adiponectin, apelin and omentin. One of the roles of omentin is reducing insulin resistance.The purpose of this study was to compare the effects of aerobic training and resistance training on serum omentin, insulin resistance and lipid profilein women. Twenty four non-active healthy obese postmenopausal women volunteered to participate in this research. They were randomly assigned into two groups: aerobic training group (AT, n=12) resistance training group (RT, n=12). AT group carried out exercises at 55-75 percent of maximal heart rate reserve and RT group carried out training at 60-80 percent of 1RM. Dependent variables were measured in the two phases of the study, including pre-test and post-test. Blood samples were taken 24 hours before starting the first training session and also 48 hours after the last training session. Results of paired samples t-test did not show any significant difference between changes in serum omentin and insulin resistance after aerobic training and resistance training. However, independent samples t-test show significant changes in all of them. The results of intergroup variations showed that there is a significant difference between the effect of eight weeks of resistance and endurance training on the amount of omentin, insulin resistance and lipid profiles.