Acute Cardiovascular and Metabolic Effects of Exercise Training in Individuals With Insulin Resistance

Study Overview
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Brief Summary
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The overall aim of the project is to determine whether or not exercise influences cardiovascular or nervous responses to meal ingestion in individuals with insulin resistance or type 2 diabetes.

Detailed Description
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Participants will undergo a screening procedure, including telephone screening and physical examination, as well as determination of body composition and fitness. Participants will be asked to complete 5-10 days of supervised exercise training and will undergo testing to assess cardiovascular and metabolic responses to an oral glucose tolerance test, including muscle sympathetic nerve activity, blood flow, and circulating glucose and insulin concentrations at baseline and following training. In addition, day-to-day variations in blood glucose will also be monitored. The overall aim of the project is to determine whether or not acute exercise training influences postprandial metabolic, vascular or autonomic nervous system responses in individuals with insulin resistance or T2D.

Official Title
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Physical Inactivity and Insulin Resistance in Skeletal Muscle

Conditions
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Insulin Resistance

Intervention / Treatment
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* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Insulin resistant: diagnosed with pre-diabetes or fasting blood glucose >/= 100 mg/dL T2D: diagnosed by primary care physician BMI: less than 43 kg/m2 Age: 30-65 Exclusion Criteria: Smoking Insulin use (other than once daily) Underlying conditions that limit ability to exercise safely Recent weight gain or loss (>5% of body weight in 3 months) Physically active (>30 min aerobic exercise, 2 d/wk) Recent (<3 mo) changes in medication use or dose Uncontrolled T2D (HbA1c>10%) Advanced retinopathy or neuropathy Pregnancy

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exercise<br>exercise - supervised exercise (treadmill walking or cycle ergometer use) | Behavioral: Exercise<br>* daily exercise: supervised treadmill walking or cycle ergometry use<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin Sensitivity After 5-7 Days of Exercise | Insulin sensitivity measured during an oral glucose tolerance test measured by the Matsuda Index. Matsuda insulin sensitivity index= 10000/square root of [(fasting glucose × fasting insulin) × (mean glucose × mean insulin during oral glucose tolerance test). | baseline and 24h after 5-7 days of exercise | 
| Blood Flow in Response to Oral Glucose Tolerance Tests | Blood flow response in the femoral artery measured by Doppler ultrasound during and oral glucose tolerance test. Data are represented as % change in blood flow during the oral glucose tolerance at 60 minutes vs. 0 minutes (prior to drinking the glucose) | pre and 24 hours post 5-7 days of exercise | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Insulin Resistance, Type 2 Diabetes