Effects of Different Types of Exercise in Type 2 Diabetes
- Conditions
- Type 2 Diabetes
- Interventions
- Behavioral: Aerobic TrainingBehavioral: Resistance Training
- Registration Number
- NCT01182948
- Lead Sponsor
- Universita di Verona
- Brief Summary
The purposes of this study are: a) to compare the effects of supervised programs of aerobic training or resistance training on the metabolic control of type 2 diabetes; b) to investigate some potential pathophysiologic and molecular mechanisms underlying these effects; c) to assess whether some changes may persist over time after termination of the supervised programs.
- Detailed Description
Meta-analyses of studies which evaluated the effects of interventions based upon structured exercise programs in patients with type 2 diabetes show that regular physical activity may improve glycosylated haemoglobin (HbA1c) by 0.6-0.7%. Most studies assessed the effects of aerobic exercise. However, recent data suggest that resistance training may result in similar effects. It seems likely that these beneficial results are obtained through different molecular mechanisms by aerobic training and resistance training. Consequently, these exercise modalities could be synergistic in improving the metabolic abnormalities in these subjects. On the other hand, comparison data are very limited.
Aims of the protocol are to compare the effects of aerobic training or resistance training on the metabolic control of type 2 diabetes and to investigate some potential pathophysiologic and molecular mechanisms underlying these effects.
The study will be carried out in 40 sedentary type 2 diabetic patients without diabetic complications, aged 40-70 yr, with body mass index (BMI) between 24-36 kg/m2 and HbA1c between 6.5-9.0%. Admitted diabetes treatments will be diet and oral hypoglycemic agents.
Subjects will be assigned, by a randomization schedule weighted by baseline BMI and fitness, to 2 groups of supervised exercise: aerobic training or resistance training. Training programs will have a similar volume and will be scheduled in three 60 min sessions per week for 4 months. During the study subjects will be instructed to follow an isocaloric diet. Before and at the end of the exercise training the following will be assessed: HbA1c (primary outcome), plasma glucose, lipid profile, blood pressure, insulin sensitivity (glucose clamp), body composition (Dual energy X-ray absorptiometry, DEXA), liver and muscle fat content (magnetic resonance imaging), expression in the muscle of some genes involved in ATP production, mitochondrial biogenesis and substrate utilization, markers of inflammation, oxidative stress and early vascular damage, peak oxygen uptake (VO2peak) during a maximal exercise test, other exercise tests, tissue oxygen extraction during exercise (Near-infrared spectroscopy, NIRS), energy expenditure and physical activity in daily life (metabolic Holter and questionnaire). Monitoring of blood glucose will also be carried out over a 48h period, comprising an exercise session (Continuous Glucose Monitoring System).
Metabolic features, exercise tests, body composition, daily physical activity and expression of relevant genes in the muscle will also be assessed 1 yr after completion of the training programs, to establish whether some changes may persist over time.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 40
- BMI between 24-36 kg/m2;
- HbA1c between 6.5-9.0%;
- diabetes diagnosis must have been made at least 1 yr previously;
- admitted diabetes treatments will be diet and oral hypoglycemic agents;
- baseline physical activity, estimated by the IPAQ questionnaire, lower than 1000 MET min per week;
- baseline body weight stable (changes lower than 2 kg in the last 2 months).
- moderate-severe somatic or autonomic neuropathy;
- coronary heart disease;
- peripheral or cerebral vascular disease;
- preproliferative or proliferative retinopathy or chronic renal failure (serum creatinine >1.4 mg/dl in females; >1.5 mg/dl in males);
- therapy with beta-blocker drugs;
- smokers;
- acute clinically significant intercurrent diseases;
- inability to perform the scheduled physical activity programs.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Aerobic Exercise Aerobic Training The aerobic training group will use cardiovascular training devices. Resistance Exercise Resistance Training The resistance training group will perform exercises on weight machines and free weights.
- Primary Outcome Measures
Name Time Method Change in haemoglobin A1c (HbA1c) levels 4 months The measurement of HbA1c is carried out with a DCCT (Diabetes Control and Complications Trial)-aligned method.
- Secondary Outcome Measures
Name Time Method Change in body weight 4 months Change in total cholesterol levels 4 months Change in liver and muscle fat content 4 months Measured by Magnetic Resonance Imaging
Change in LDL-cholesterol levels 4 months Change in triglycerides levels 4 months Change in energy expenditure 4 months Measured by indirect calorimetry
Change in peak oxygen uptake 4 months Measured during an incremental exercise test
Changes in expression in the muscle of some genes involved in ATP production, mitochondrial biogenesis and substrate utilization 4 months mRNA analysis with multiplex tandem real-time PCR of fine needle aspirates obtained from the vastus lateralis muscle
Change in fasting plasma glucose levels 4 months Change in beta-cell function 4 months Measured by OGTT (Oral Glucose Tolerance Test)
Change in tissue oxygen extraction 4 months Measured by NIRS (Near-infrared spectroscopy) during an incremental test exercise
Change in body composition 4 months Assessment by DEXA (Dual energy X-ray absorptiometry)
Change in HDL-cholesterol levels 4 months Change in blood pressure 4 months Change in blood glucose during and after exercise 48 hours Measured by continuous glucose monitoring system
Muscle strength 4 months Measured by 1RM (one-repetition maximum) test
Change in flexibility 4 months Measured by "sit and reach" test and "back scratch" test
Compliance 4 months Attendance at the scheduled sessions is recorded for each patient.
Change in energy expenditure through voluntary physical activity 4 months Energy expenditure is estimated through metabolic Holter (Sense Wear Armband) and IPAQ (International physical activity questionnaire).
Change in insulin sensitivity 4 months Measured by euglycemic hyperinsulinemic clamp
Change in antidiabetic medications 4 months Class and dosage of blood-glucose lowering drugs are recorded before and at the end of the protocol.
Change in 6 minutes walk distance 4 months This test measures the number of meters that can be walked in 6 minutes over a 30 m course. It is a simple field test to assess aerobic functional capacity.