High-Intensity Exercise and Endothelial Function in Type 1 Diabetes(HIIT-T1D)

Study Overview
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Brief Summary
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To study the effect of 8 week high-intensity interval training (HIIT) compared with moderate intensity (MCT) interval training and sedentary patients(CON) with type 1 diabetes. Adult T1DM patients without known complications are randomised in blocks into these 3 groups according to their baseline flow mediated dilation (FMD). After 8 week exercise training, the main outcome, FMD, is re-evaluated. Additional variables such as VO2 peak for cardiovascular fitness, oxidative stress and endothelial independent vasodilation to study vascular rigidity are also evaluated.

Detailed Description
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In a randomized controlled open trial, 36 adult type 1 diabetes mellitus (T1DM) patients without known complications were randomized into 3 groups: HIIT n=12; MCT n=12 and a sedentary control group (CON) n=12. Total sample size was calculated to a power of 80% alha 0.05 and a difference in mean FMD of 2%. Before randomisation, flow mediated dilation (FMD) and maximal exercise capacity (VO2 peak)is determined. Block Randomisation based on FMD rank values are done to equalize baseline FMD. Exercise sessions are performed in cycle ergometers during 40 minutes, 3 times a week, along 8 weeks. HIIT protocol, intensity vary from 50 to 85% of the maximum heart rate (HRmax), while in MCT, HR remained stable at 50% HRmax. Endothelial function was measured by flow mediated dilation (FMD) for endothelium-dependent vasodilation (EDVD) and smooth-muscle function was measured by nitroglycerine mediated dilation (endothelium independent vascular dilation) - (EIVD). Peak oxygen consumption (VO2peak) and oxidative stress markers were determined before and after the training period. ED was defined as an increase of less than 8% in vascular diameter after cuff release.

Official Title
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Effect of High-Intensity Interval Exercise Training Compared With Moderate-intensity Continuous Training on Endothelial Function and Cardiorespiratory Fitness of Type 1 Diabetes Patients

Conditions
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Type 1 Diabetes Mellitus, Endothelial Dysfunction

Intervention / Treatment
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* Behavioral: High Intensity Interval Training
* Behavioral: Moderate Continuous Exercise Training
* Other: Non-exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: T1DM Physically inactive or not involved in exercise training programs in the previous 6 months Interested in starting an exercise training program. Exclusion Criteria: Smokers, Pregnancy Co-morbidities not related to diabetes Drugs other than insulin Loss of renal function (serum creatinine above 1.5 mg/dl), Moderate to severe retinopathy or blindness, Suspected or confirmed coronary artery disease, Severe peripheral neuropathy Foot ulcers or history of previous foot ulcer Suspected or confirmed clinical autonomic neuropathy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomised Clinical Trial, 3 parallel groups: HIIT ( High-Intensity Interval Training) MCT (moderate intensity continuous training) and Sedentary Control Group.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Intensity Interval Training<br>High Intensity Interval Exercise Training in cycle ergometer 3 times a week for 8 weeks | Behavioral: High Intensity Interval Training<br>* High Intensity Interval Exercise Training in cycle ergometer, exercising at 80% of maximal capacity during one minute alternated with exercise at 50% of maximal capacity during 4 minutes intervals, for a total of 30 minutes. Three times a week for 8 weeks<br>|
| Active Comparator: Moderate Continuous Exercise Training<br>Moderate Continuous Interval Training | Behavioral: Moderate Continuous Exercise Training<br>* Moderate Continuous Exercise Training 3 times a week for 8 weeks at 50% of maximal capacity<br>|
| Other: Non-exercise<br>Sedentary Type 1 Diabetes Controls. | Other: Non-exercise<br>* Conventional care for sedentary Type 1 Diabetes Controls. No intervention.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Endothelial Dependent Mediated Vascular Dilation | Percent of change from baseline in flow mediated dilation measured through arterial ultrasound at right arm | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak oxygen consumption | Percent of change in maximal oxygen capacity measured by in maximal oxygen consumption | 8 weeks | 
| Endothelial independent vascular dilation | Percent of change from baseline in nitrate mediated dilation measured through arterial ultrasound at right arm | 8 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise, High-Intensity Interval Training, Type 1 diabetes, Endothelial Dysfunction