Influence of Endothelial Function on Central and Peripheral Causes Of Exercise Impairment in Type 2 Diabetes
Condition: Type 2 Diabetes
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional

Summary: 
      This study will evaluate the effects of impaired blood flow regulation on exercise. It will
      also determine whether the effects are more important in the heart or in the skeletal muscle
      tissue during exercise. In addition, this study will decide whether temporarily reversing
      these problems will improve blood flow control, improve heart and muscle tissue function and
      help improve exercise capacity in person with type 2 diabetes. This study will do so using
      two methods: (1) by giving vitamin C intravenously (IV) and (2) a three month exercise
      training program. Up to 100 subjects will be enrolled in this study.
    

Detailed description: 
      The investigators have found that persons with type 2 diabetes have an impaired ability to
      perform exercise even without clinically apparent complications. The reasons for this marked
      abnormality are unknown but are important as the decreased ability to exercise could
      contribute to the decreased expenditure of physical activity frequently observed in this
      population and may potentially constitute an early marker of cardiovascular disease.

      The investigators wish to evaluate the effects of impaired blood flow regulation on exercise
      capacity and whether the effects are more important in the heart or in the skeletal muscle
      tissue during exercise. In addition, the investigators are determining whether correcting
      these abnormalities by two methods of improving blood flow regulation (acutely infusing
      Vitamin C or three months of chronic exercise training) leads to improved blood flow
      regulation, improved heart and skeletal muscle tissue function and hence to better exercise
      capacity in person with type 2 diabetes. This information will provide a more mechanistic
      understanding of causes of abnormal exercise responses observed in person with type 2
      diabetes as well as whether and to what degree responses are modifiable. Interventions that
      reverse the exercise defect may facilitate patient adherence to prescribed physical activity
      programs and potentially decrease cardiovascular mortality in this large segment of the
      population.
    

Intervention name(s): Exercise program; Ascorbic Acid (Vitamin C)
Intervention type(s): Behavioral; Drug
Intervention description(s): Three month exercise program located at the Anschutz Medical Campus at I-225 and Colfax. The program runs three times per week for about an hour each session. Gym is open Monday - Saturday during specific hours (morning, noon, evening).; During one exercise study visit, 0.06 grams of Vitamin C per kilogram fat-free mass per 100 milliliters (mL) of normal saline administered; Subjects will receive a bolus of 100mL Vitamin C solution given at 5ml/minute over 20 minutes followed by a "drip-infusion" given at 1.7ml/minute.
Other intervention name(s): Exercise Training; Ascorbic Acid; Vitamin C
Intervention MeSH terms: Vitamins; Ascorbic Acid
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Health Services Research
Keywords: Type; 2; Diabetes; Blood; Vessel; Function; Exercise; Program; Intervention; Vitamin; C; Men; Women; Blood vessel function