Shivering and Glucose Homeostasis

Study Overview
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Brief Summary
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The purpose of this study is to investigate the effect of prolonged shivering thermogenesis on glucose homeostasis in overweight/obese humans.

Official Title
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The Effect of Prolonged Shivering Thermogenesis on Glucose Homeostasis in Overweight/Obese Humans

Conditions
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Healthy Overweight/Obese

Intervention / Treatment
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* Other: Cold exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Signed informed consent Caucasian Healthy (as determined by dependent physician based on medical questionnaire) Man, or postmenopausal (defined as at least 1year post cessation of menses) woman Aged 40 - 75 years at the start of the study BMI 27 and 35 kg/m2 Stable dietary habits (no weight loss or gain >3kg in the past 3 months) Exclusion Criteria: - Not meeting all inclusion criteria Medication use known to hamper subject's safety during study procedures Co-morbidities to which the intervention or program that may pose as a complicating factor Subjects diagnosed with cardiovascular diseases or cancer Fasting plasma glucose ≥ 7.0 mmol/l Haemoglobin < 7.8 mmol/l for women, or < 8.4 mmol/l for men Previously diagnosed with type 2 diabetes Abuse alcohol/drug abuse Subjects who do not want to be informed about unexpected medical findings during the screening/study or do not wish that their physician is informed. Engagement in structured exercise > 2h per week Participation in another biomedical study within 1 month before the first study Smoking Cold-acclimated, such as takes daily extended cold baths, works in a refrigerated environment, or regular cold-water swimming within 1 month of starting the study

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 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
Interventional Model Description: a single arm, longitudinal study (10-day intermittent shivering exposure) in a pre-post design
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cold acclimation arm<br>An oral glucose tolerance test will be performed on day 1 of the study. The next day (day 2), subjects will be exposed to shivering thermogenesis for at least 1 hour. The day after, an oral glucose tolerance test will be performed (day 3). The following 9 days, subjects will be exposed daily to shivering thermogenesis for at least 1 hour (day 4-12). On the last day (day 13), an oral glucose tolerance test will be performed. | Other: Cold exposure<br>* Subjects will be exposed to shivering thermogenesis for at least 1 hour for 10 days<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| area under the curve (AUC) of the glucose tolerance test | area under the curve (AUC) of the glucose tolerance test before cold exposure, 1 day after cold exposure and after 9 consecutive days of cold exposure. | 1 day following cold exposure and following 9 consecutive days of cold exposure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| skeletal muscle GLUT4 translocation | Comparison between skeletal muscle GLUT4 translocation, as assessed by wide-field microscopy both before and after cold acclimation | 1 day following cold exposure and following 9 consecutive days of cold exposure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Type 2 diabetes mellitus, Shivering thermogenesis, skeletal muscle