Winter-Swimming and Brown Adipose Tissue Activity in Middel-aged Obese Subjects (WinterBAT).

Obesity Clinical Trial

— WinterBAT  

Official title:

The Impact of Winter Swimming on Brown Adipose Tissue Recruitment and Metabolic Health in Middel-aged Obese Pre-diabetic Subjects.

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT03541096
• Other study ID #: H-18015882 WinterBAT-Study
• Status: Active, not recruiting
• Phase: N/A
• Start date: November 7, 2018
• Est. completion date: December 31, 2024

Study information

• Verified date: April 2024
• Source: Rigshospitalet, Denmark
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study investigates repetitive cold-water exposure on brown fat activity assessed by PET/CT scanning. Furthermore we will assess glucose control upon winter-swimming. Obese prediabetic men and women will be randomized to winter-swimming or control conditions for 4 months.

Description:

Brown fat (BAT) is an energy-consuming tissue. Long-term activation of BAT in adults increases clearance of blood glucose and non-esterified fatty acids (NEFA), insulin sensitivity and metabolic rate. Moreover, adipokines released from BAT, known as batokines, represent a promising but currently unexplored area in terms of metabolic regulation. Cooling activates BAT; however, current cooling protocols fail to activate BAT in a large part of the population. Whether this failure in activation is related to biology, inefficient detection or cooling protocols is unknown. With our initial acute cooling study (protocol number: H-16038581), these protocols have successfully been optimized whereupon novel batokines will be identified. Having established a methodology for assessing BAT activity and batokine profiles, a longer-term cooling intervention (winter swimming) will be performed to examine the effect of repetitive cold-water exposure on BAT activity. Obese pre-diabetic subjects will be included in a 4-month supervised winter swimming (WS) intervention.

It is hypothesized, that repetitive cold-water exposure constituted by WS, increase BAT activation and volume, followed by improved glycemic control in obese pre-diabetic subjects.

Method The study is a randomized controlled, parallel-group intervention study. The investigator will recruit 30 obese pre-diabetic non-winter-swimmers to participate in a WS intervention group (n=15) or control group (n=15) with no WS activities. Subjects will either be randomized to the WS group, who will winter-swim 4 months, 2-3 times/week including sauna-visits if desired, or control conditions with no WS during the 4 months (October to May).

Main aims

• To assess whether WS will have an immediate effect on BAT recruitment or function.

• To assess whether WS will have an effect on glycemic control.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 30
• Est. completion date: December 31, 2024
• Est. primary completion date: June 1, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 40 Years and older

Eligibility

Inclusion Criteria:

• Waist circumference above 80 cm for women and 94 cm for men.

• BMI > 25 but <40 kg/m2

• Age > 40 years.

• Low to moderate physical activity level (no physical activity or on average 30 minutes of moderate physical activity per day and not more than 3 hours of training pr. Week)

Subjects will be included in either one of these cases after the screening:

• Fasting plasma glucose above 5.6 millimol per liter (mmoL/L).

• HbA1C >39 millimol per mol (mmol/mol).

• 2 hour plasma glucose after a 75 g. oral glucose tolerance test (OGTT) above 7.8 mmol/L.

Exclusion Criteria:

• Winter swimmer

• Any history of Cancer,

• Clinically significant liver, kidney, heart, inflammatory or lung-disease.

• Pregnancy

• Taking medication (not for hay fever), including glucose-lowering treatment.

• HbA1c >55 mmol/mol and/or 2-h plasma glucose in the 75-g OGTT > 15 mmol/L, fasting plasma glucose above 6.9.

• Iron deficiency

• Increased International Normalised Ratio for coagulation (INR).

• Femoral hernia, vene prostheses (pants prosthesis), thrombs in v. Femoralis.

• Abnormal ultrasound echocardiography of the heart found at the health-examination day.

• Contraindications to cold exposure including severe Raynauds disease.

• History of alcohol abuse or use of more than 14 units pr. Week.

• History of drug abuse, including marihuana.

• Smoking including occasional smoking.

• Pacemaker or other electronics implanted in the body.

• Claustrophobia, communication problems, including understanding the experimental protocol.

• History of contrast allergy.

Related Conditions & MeSH terms

• Adipose Tissue, Brown
• Brown Adipose Tissue
• Cold Exposure
• Diabetes Mellitus, Type 2
• Obesity
• Type 2 Diabetes Mellitus
• Uncoupling Protein 1
• Winter Swimming

Intervention

Behavioral:
• Winter Swimming
Supervised Winter Swimming in Copenhagen
• Control group
No winter swimming activities.

Locations

Country	Name	City	State
Denmark	Center for Inflammation and Metabolism/ Center for Physical Activity Research	Copenhagen

Sponsors (1)

Lead Sponsor	Collaborator
Kristian Karstoft

Country where clinical trial is conducted

Denmark, 

References & Publications (5)

Gibas-Dorna M, Checinska Z, Korek E, Kupsz J, Sowinska A, Krauss H. Cold Water Swimming Beneficially Modulates Insulin Sensitivity in Middle-Aged Individuals. J Aging Phys Act. 2016 Oct;24(4):547-554. doi: 10.1123/japa.2015-0222. Epub 2016 Aug 24. — View Citation

Hanssen MJ, Hoeks J, Brans B, van der Lans AA, Schaart G, van den Driessche JJ, Jorgensen JA, Boekschoten MV, Hesselink MK, Havekes B, Kersten S, Mottaghy FM, van Marken Lichtenbelt WD, Schrauwen P. Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. Nat Med. 2015 Aug;21(8):863-5. doi: 10.1038/nm.3891. Epub 2015 Jul 6. — View Citation

Hanssen MJ, van der Lans AA, Brans B, Hoeks J, Jardon KM, Schaart G, Mottaghy FM, Schrauwen P, van Marken Lichtenbelt WD. Short-term Cold Acclimation Recruits Brown Adipose Tissue in Obese Humans. Diabetes. 2016 May;65(5):1179-89. doi: 10.2337/db15-1372. Epub 2015 Dec 30. — View Citation

Lee P, Smith S, Linderman J, Courville AB, Brychta RJ, Dieckmann W, Werner CD, Chen KY, Celi FS. Temperature-acclimated brown adipose tissue modulates insulin sensitivity in humans. Diabetes. 2014 Nov;63(11):3686-98. doi: 10.2337/db14-0513. Epub 2014 Jun 22. — View Citation

van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, Drossaerts JM, Kemerink GJ, Bouvy ND, Schrauwen P, Teule GJ. Cold-activated brown adipose tissue in healthy men. N Engl J Med. 2009 Apr 9;360(15):1500-8. doi: 10.1056/NEJMoa0808718. Erratum In: N Engl J Med. 2009 Apr 30;360(18):1917. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Difference between groups in change in brown adipose tissue (BAT) activity during cooling	BAT activity is measured using positron emission tomography (PET)- Computer tomography (CT) scan. The PET-CT scan uses a glucose-radiotracer (fludeoxyglucose-18 (FDG)) to measure the glucose uptake in BAT, which is associated with BAT activity. FDG is injected following one hour of cooling and the subjects are scanned following one additional hour of cooling. The subjects are continuously cooled throughout the scanning procedure. Difference between groups in change in FDG tracer uptake (post minus pre intervention) during 1,5 hours of cooling is calculated.	Day 0 (before intervention) and Day 120 (after intervention)
Secondary	Difference between groups in change in glycemic control	Glycemic control is measured using a 4 hour mixed meal tolerance test. Difference between groups in change in the mean MMTT glucose levels during the MMTT (post minus pre intervention) will be calculated.	Day 0 (before intervention) and Day 120 (after intervention)