The Impact of Passive Heat Treatment on Glycaemic Response During an Oral Glucose Tolerance Test in Diabetic Patients

Study Overview
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Brief Summary
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Type 2 diabetes mellitus (T2DM) is a metabolic disease with a rapidly increasing incidence world-wide. The disease is characterizedby a decreased glucose tolerance as a result of insulin resistance, resulting in poor blood glycaemic control. Blood glucose loweringmedications are widely available, but their effect stagnates as T2DM progresses. New treatment regimens are required to combatthe disease. Although therapies such as physical exercise have been shown to induce beneficial effects on glycaemic control inT2DM patients, not all patients are able to perform exercise. Passive heating treatment (PHT) might be an alternative strategy toreduce insulin resistance, as it has been postulated to have comparable effects on the cardiovascular system as exercise. PHT hasbeen linked to numerous health benefits, including improved cardiovascular- and pulmonary function, pain alleviation and metabolichealth. In addition, long term use of PHT shows promising effects on glycaemic control in T2DM patients. However, the acute effectsof PHT on glucoregulation are yet to be determined. Therefore, in this study we will assess the acute impact of passive heat treatment on the post-prandial glycaemic response during an OGTT in T2DM patients

Official Title
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The Impact of Passive Heat Treatment on Glycaemic Response During an Oral Glucose Tolerance Test in Diabetic Patients

Conditions
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Diabetes Mellitus, Type 2

Intervention / Treatment
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* Device: Infrared sauna heating
* Device: Sham sauna


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged ≥50 years old Body mass index 18.5 - 35 kg/m2 DM type 2 Using oral blood glucose lowering medication Able to give informed consent Exclusion Criteria: Insulin dependence Changes in diabetes medication in the past 3 months Allergy for one of the food items used >5% weight change in the previous 6 months Participating in a structured (progressive) exercise program, or in the past 3 months. Frequent (once per week or more) user of infrared (or traditional) sauna in the past 3 months Inability to tolerate sauna/high temperatures Smoking Diagnosed with cardiovascular disease (e.g. unstable angina pectoris or recent myocardial infarction), kidney failure (eGFR < 60 ml/min/1.73m2), rheumatoid arthritis Diagnosed musculoskeletal, GI tract, metabolic (except diabetes) or pulmonary (e.g. COPD) disorders that are expected to influence study outcomes Having a pacemaker, defibrillator, or any other type of metal implant

Ages Eligible for Study
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Minimum Age: 50 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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Crossover, randomized, controlled trial
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Non-heated sauna session<br>The test days will consist of sitting in an infrared sauna cabin (HM-LSE-3 Professional edition, Health Mate, Belgium). Participants will sit in an infrared sauna at 21° Celsius for a total of 40 minutes. | Device: Sham sauna<br>* Participants will sit in an inactive infrared sauna at room temperature (21° Celsius) for a total of 40 minutes.<br>|
| Experimental: Heated sauna session<br>The test days will consist of sitting in an infrared sauna cabin (HM-LSE-3 Professional edition, Health Mate, Belgium). Participants will sit in an infrared sauna at 60° Celsius (humidity not controlled in an infrared sauna) for a total of 40 minutes. | Device: Infrared sauna heating<br>* Participants will sit in an infrared sauna at 60° Celsius (humidity not controlled in an infrared sauna) for a total of 40 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glycaemic response (Matsuda index) | OGTT | 120 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HOMA-IR | fasting glucose and insulin values | Baseline | 
| Plasma volume/hematocrit |  | Throughout test day (3h) | 
| Gutt insulin sensitivity index | from OGTT values | 120 minutes |