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Completed

NCT Number: NCT03095846

Cold Induced Activation of Brown Adipose Tissue in Winter Swimmers

This study investigates cold-induced brown fat activation in winter swimmers and not-winter swimmers by skin temperature measures assessed with infra red thermography imaging and skin temperatures. Winter swimmers and not-winter swimmers will participate in an acute cooling intervention and thermoneutral intervention for comparison of energy expenditure and skin temperatures at the supraclavicular area.

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Key information

Conditions

Adipose Tissue Adipokines BAT Brown Adipose Tissue Brown Fat Infra-red Thermography Proteins Proteomics Type2 Diabetes Uncoupling Protein 1 Winter Swimmers

Age range

18 year–35 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Center for Inflammation and Metabolism/ Center for Physical Activity Research

Copenhagen, 2100, Denmark

About this study

The field of human brown adipose tissue (BAT) research is focused on activation of BAT as a means of manipulating energy expenditure and potentially anti-obesity and anti-diabetic properties of the tissue. This is well established in rodent studies and explained as due to the specific brown fat uncoupling protein 1 (UCP1). Despite increasing evidence that indicates a metabolic regulatory role of BAT in humans, BAT activation/recruitment is not fully understood.

Cold induced brown fat activity will be measured by skin temperature measures by means of infra-red thermography imaging and skin temperature.

15 healthy male winter swimmers and 8 healthy male non-winter swimmers (controls) will be included in the study.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age 18-35 years. Men Caucasian white Body Mass Index 19-25 kg/m2. Moderate physical activity level (not more than 8-10 hours of training pr. Week) Ability to give informed consent. Ability to follow verbal and written instructions in Danish. Body fat percent under 21% measured at the pre-examination day. Winter swimmers: Min. 2 swim/ week. Swimming in winter-season in open water outdoor in Denmark from September/October until study start in March.

Not-winter swimmers: Not winter-swimmers or taken cold showers on a regular basis.

Exclusion criteria

  • Chronic diseases: Hormonal: Metabolic Diseases mb. Graves, hypothyroidism, myxedema and goiter. Diabetes Melitus, Coronary heart disease (history of myocardial infarction, unstable angina pectoris, or congestive heart failure), cancer treated within last 3 years.

Tobacco, marijuana or intravenous drug use within 1 year of screening. Dieting, recent weight loss (>3 kg within 3 month) or a history of an eating disorder.

Dietary supplements. History of depression, psychosis, or other psychiatric illness requiring hospitalization.

Alcohol consumption >14 units/week. History of alcohol abuse within the past 3 years. Known liver disease or elevated liver biomarkers more than 2 times upper normal levels in the preliminary investigation.

Known kidney disease or elevated kidney biomarkers, in the preliminary investigation.

Use of daily medications, except for seasonal use of antihistamines. Diagnosed sleep disturbances.

Treatment and study plan

cooling

Procedure

Individualized cooling protocol

Other names: Cold activation, Cold stimulation, Cold activation of BAT

Primary outcomes

  1. 5. Difference in brown adipose tissue (BAT) activity after cooling between Winter Swimmers (WS) and No-Winter Swimmers (NWS).

    Time frame: Difference in peak temperature after 2 hours of cooling.

    BAT activity is measured by skin temperature in the supraclavicular BAT depot using infrared thermography imaging. Difference between peak temperature change (peak temperature minus baseline temperature) during 2 hours of cooling is calculated.

Secondary outcomes

  1. Difference in glucose control between WS and NWS.

    Time frame: Difference in glucose control between WS and NWS after a 2 hours glucose tolerance test under thermoneutral conditions.

    Difference in glucose control between WS and NWS in an oral glucose tolerance test measured as incremental area under the curve (iAUC).

  2. Difference in resting energy expenditure after cooling versus no cooling

    Time frame: Difference in resting energy expenditure after 2 hours of cooling versus 2 hours of no cooling.

    Difference in resting energy expenditure after cooling versus no cooling between WS and NWS measured as mean difference in kilojoule per minute.

Sponsors and collaborators

Lead sponsor

Rigshospitalet, Denmark

Other

Registry information

Official study title

Cold Induced Activation of Brown Fat in Winter Swimmers

Acronym: COLDBAT_WS

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
Mar 30, 2017
Registry last updated
Mar 27, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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