Leiden University Medical Center
Leiden, 2333ZA, Netherlands
NCT Number: NCT04406922
This study aims to investigate whether maximum cold-induced non-shivering thermogenesis (e.g. thermogenesis as a consequence of BAT activity) differs between morning and evening.
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Notify Me18 year–35 year
All sexes
Interventional
Not applicable
Leiden, 2333ZA, Netherlands
Brown adipose tissue (BAT) recently emerged as a novel player in energy expenditure (EE) in humans as it combusts fatty acids and glucose towards heat. Human BAT can be activated by sympathetic stimulation resulting from cold exposure or treatment with sympathomimetic drugs. Short-term acclimation to mild cold was shown to reduce fat mass in obese subjects and decrease peripheral insulin resistance of patients with T2DM. Recently, in preclinical studies the investigators showed that BAT has a circadian rhythm. It is currently unknown whether this is also the case in humans. The investigators postulate that BAT activity should display a circadian rhythm that adapts to changes in circadian behavior, and may determine glucose/lipid levels throughout the day.
Healthy volunteers accepted: Yes
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
As an intervention, a personalized cooling protocol will be used in order to activate BAT and induce non-shivering thermogenesis. During the cooling procedure, subjects will be exposed to mild cold (approx. 14°C) for 150 min. Since the onset temperature of shivering shows a high interindividual variation, we will use a personal cooling protocol to ensure maximum non-shivering EE (and thus an equal maximum activation of BAT). The right temperature will be determined via a subjective method, e.g. to ask the subject if he or she experiences shivering. The time needed to achieve the right temperature is approximately 30-60 minutes. Then, the stable cooling period of 90 min is started. During this time the subject will be asked every 15 minutes whether he is experiencing shivering. If so, temperature will be increased with 2-3°C so that shivering just stops.
Time frame: Change in cold-induced non-shivering thermogenesis between morning (total duration of measurement 120 minutes) and evening (total duration of measurement 120 minutes). The time frame comprising both the morning and evening measurement will be 72 hours.
Thermogenesis is estimated by the change in energy expenditure after cold exposure, measured by indirect calorimetry. This will be measured in the morning and in the evening.
Time frame: Change between morning and evening: measured at several timepoints during 3.5 hours. The time frame comprising both the morning and evening measurement will be 72 hours.
Serum glucose (mmol/L) before and during cold exposure in the morning versus the evening.
Time frame: Change between morning and evening: measured at several timepoints during 3.5 hours. The time frame comprising both the morning and evening measurement will be 72 hours.
Serum insulin (pmol/l) before and during cold exposure in the morning versus in the evening.
Time frame: Change between morning and evening: measured at severaltime points during 3.5 hours. The time frame comprising both the morning and evening measurement will be 72 hours.
Cholesterol (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) in serum (mmol/L). Before and during cold exposure in the morning and in the evening.
Time frame: Change between morning and evening: measured at severaltime points during 3.5 hours. The time frame comprising both the morning and evening measurement will be 72 hours.
Triglycerides, glycerol and free fatty acids in serum (mmol/L). Before and during cold exposure in the morning and in the evening.
Time frame: Change between morning and evening: measured before and after cold exposure. The time frame comprising both the morning and evening measurement will be 72 hours.
Norepinephrine, epinephrine (μM/ml)
Time frame: Change between morning and evening: measured every 60 seconds during cold exposure on both study days. The time frame comprising both the morning and evening measurement will be 72 hours.
Wireless iButtons and infrared camera
Leiden University Medical Center
Other
The Impact of Circadian Rhythmicity in Cold-induced Thermogenesis in Lean and Obese Subjects
Acronym: COLDR
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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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