@2024 Afarand., IRAN

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ISSN: 2252-0805    The Horizon of Medical Sciences 2016;22(2):137-143

Background
… [1-16] Aerobic exercise training can be effective on type II diabetes control [17]. Identification of more beneficial exercise program helps people to achieve their desired goal in the shortest possible time using the most effective and safest method of training [18].
Previous Studies
High-intensity interval training program increases fat oxidation during the exercise in women, improves insulin function in inactive young people, and increases the oxidative capacity of skeletal muscle [19-21].
Aim(s)
This study aimed to investigate the effect of eight weeks aerobic interval training on HbA1c and insulin resistance index in women with type II diabetes.
Research type
This is a semi-experimental research.
Research society, place and time
Women with type II diabetes referred to diabetes clinic of Golestan hospital were studied in 2012.
Sampling method and number
30 subjects were selected using convenience sampling.
Used devices&materials
The subjects were randomly divided into two groups including control and experimental groups (n= 15 per group). Participants were at the age range of 33-53years with the history of type II diabetes for at least two years. They were orally using metformin, glibenclamide, and gliclazide drugs during the study. 24 hours before the start of the study, fasting subjects attended the laboratory of Research Center of Endocrinology and Metabolism in Golestan hospital; and under laboratory conditions, 5mlvenous blood was taken. 48 hours after the last training sessions, the measurement was conducted under similar conditions. The training course was lasted three sessions per week for 8 weeks. And the training program of experimental group included the main training on the ergometer bicycle. Working load was added in the main stage of riding from the first week to the eighth week and it continued from six internals on the first week to 12 intervals on the eighth week. In interval training activities, subjects were riding with 65% of their maximum power, and in the resting stage, they were riding with 30-40% of their power, and this amount reached to 80% of subjects` power in the eighth week. The duration of activities was increased from 30 seconds training and 180 second active resting in the first week to 60 seconds training and 180 seconds active resting in the eighth week. To measure blood glucose level before and during the exercise, glucometer (Gluco plus Monitoring System; Iran) was used. Body composition was evaluated using the body composition analysis machine (Olympia version 3.3; Guan Company; South Korea). The participants` peak oxygen consumption was measured by ergometer bicycle (model 839E; Sweden) using Storer-Davis test. The measurement of HbA1c was carried out using a kit (BioSystems Co.; Barcelona; Spain) through ion-exchange chromatography intra-Assay CV: 5.4% (intra-Assay CV: 7.3%). The insulin concentration, also, was measured using a kit (no: 12017547122Cat; Cobas® Co. product; USA) using electrochemiluminesence method (intra-Assay CV: 1.9%, inter- Assay CV: 2.6%) and using a device (Elecsys 2010 Hitachi; Germany). Glucose, also, was measured using the enzyme glucose oxidase method with a kit (Parsazmoon; Iran) by auto-analyzer (Cobas Mira, BC 5300; Germany). The insulin resistance index (HOMA-IR) was calculated through the formula “[Fasting Glucose (mmol /L)×Fasting Insulin (mU/L)]/22.5”. Descriptive statistics were used to calculate the mean and standard deviation of the variables. To assess the normality of data distribution, Shapiro-Wilks test was used. T-test was used for intra-group comparison, and covariance was used for inter-group comparison with elimination of pretest effect. All statistical calculation was performed by SPSS 17 software.
Findings by Text
The mean age of experimental group was 47.85 ± 4.52 years and their mean height was 156.92 ± 8.45 cm, and control group had the mean age 45.25 ± 6.86 years and the mean height 157.00 ± 5.29 cm. Also, the mean duration of diabetes in experimental group was 3.28 ± 1.79 years and it was 7.37 ± 4.89 years in control group. Comparison of intra-group changes showed that after eight weeks aerobic interval training, body mass index, waist to hip ratio, body weight and body fat percentage did not have significant decrease in the diabetic women (p>0.05), whereas peak oxygen consumption value was significantly increased in diabetic women (p<0.05). However, no significant difference was observed between the results of pretest and posttest of these values in control group (p>0.05). Also, the reduction in HbA1c and fasting glucose level after aerobics interval training was not significant in experimental group, but serum insulin and insulin resistance was significantly decreased. These changes were not significant in control group. In inter-group comparisons, no significant difference was observed between the amount of HbA1c and fasting glucose in control and experimental groups. However, a significant difference was observed between the insulin serum values and resistance to insulin in two groups (Table 1).
Main comparison to the similar studies
Aerobic interval training did not have a significant effect on HbA1c, fasting glucose, body mass index, body fat percentage, waist to hip ratio and body weight. However, it had a significant effect on the insulin serum and insulin resistance index. These results are consistent with some studies, and were inconsistent with some other studies. 12 weeks aerobic exercise, three days a week, and 30-40 minutes per session with intensity 50-80% of maximum oxygen uptake, has reduced the amount of HbA1c and fasting blood glucose in women with type II diabetes [22]. 14 weeks aerobic exercises, three days a week and 50 minutes per session, with the intensity 60-70% of peak oxygen consumption significantly decreases the amount of HbA1c and fasting glucose in these patients. The amount of GLUT4 (glucose transporter in the plasma membrane) is increased by physical activities which improves insulin action on the glucose metabolism and can reduce the amount of HbA1c [22]. 12 months aerobic exercise, twice a week with intensity 55-70% of maximum oxygen consumption in patients with type II diabetes, has significantly reduced HbA1c [23]. 12 weeks aerobic exercise with moderate intensity 65-75% of maximum oxygen consumption, three days a week and 30-45minutes each session, significantly reduced the amount of HbA1c and fasting glucose in diabetic men. The aerobic exercise training improves oxygen consumption and glycemic parameters [24]. 12 weeks aerobic exercise, five days a week, and 30-60 minutes per session with intensity 100% of peak oxygen consumption increasingly and significantly reduces fasting blood glucose [25]. 12 weeks aerobic training does not have any significant effect on the amount of HbA1c and body mass index [26]. 9 months aerobic treadmill exercise, three days a week and 140 minutes a week with intensity 50-80% of maximum oxygen consumption causes a significant decrease in HbA1c, fasting blood sugar and abdominal fat percentage [26]. 12-week aerobic exercise with progressive rate did not cause any change in the fasting blood glucose, serum insulin and insulin resistance [27]. 4 months training at 70% of peak oxygen consumption improves blood glucose in the patients with type II diabetes [27]. 8 weeks aerobic training, improves the amount of HbA1c and blood fasting glucose in type II diabetic patients [28]. Aerobic exercise for 2 weeks with intensity 90% of maximum oxygen consumption reduces blood glucose [28]. 12 weeks aerobic training, three times a week with intensity 60-65% of maximum heart rate had no significant effect on HbA1c and fasting blood glucose [29]. Aerobic interval training in patients with diabetes type II does not have any significant effect on the amount of HbA1c [30]. … [31]
Suggestions
The duration of these exercises should be increased to achieve desirable results.
Limitations
Short exercise duration and non-reliable dietary control during exercise were the outstanding limitations of this study.
Conclusions
8-week alternate aerobic exercises with an increasing intensity affect serum insulin level and insulin resistance index in type II diabetic women. Nevertheless, the exercises do not affect HbA1c level and fasting blood glucose.
Acknowledgments
All the diabetic patients in Diabetic Center of Ahvaz Golestan Hospital and the director of the lab of Physical Education and Sport Sciences of Shahid Chamran University are appreciated.
Conflict of interest
Non-declared
Ethical Permissions
This study has been confirmed by Ahwas Jondi-Shapour University of Medical Sciences.
Funding Sources
This article has been adapted from a physical education postgraduate thesis in Ahwas Jondi-Shapour University.

TABLES and CHARTS

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