Effects of Different Types of Exercise in Type 2 Diabetes
Condition: Type 2 Diabetes
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional

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.
    

Intervention name(s): Aerobic Training; Resistance Training
Intervention type(s): Behavioral; Behavioral
Intervention description(s): The aerobic training group will exercise on cardiovascular training equipment. The workload will be gradually increased up to 60% of the reserve heart rate. Subjects will exercise 3 times per week for 60 min in the Fitness Centre of the Exercise and Sport Science School. Training will be carried out in small groups, under the supervision of personal trainers. During the study subjects will be instructed to follow an isocaloric diet.; The resistance training group will perform different exercises on weight machines and free weights to exercise upper and lower extremity muscles. Participants will perform 8-10 different exercises each session, alternating abdominal, upper and lower extremity exercises. Subjects will exercise 3 times per week for 60 min in the Fitness Centre of the Exercise and Sport Science School. Training will be carried out in small groups, under the supervision of personal trainers. During the study subjects will be instructed to follow an isocaloric diet.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: aerobic training; resistance training; type 2 diabetes; therapy