Cold-induced thermogenesis in adults from Siberia and Western Europe

The effect of a single cold exposure on metabolic parameters will be studied,
and in addition a comparison between different populations will be made.
Specifically, during January 2020, the proposed daily activity and temperatures
measurements, cold-finger test, and whole-body cold exposure were performed in
a population who lives in Siberia in extreme conditions where the environmental
temperature is frequently -30 °C in the winter. Thus, this research will allow
a comparison between the non-cold acclimated Western Europeans with the cold
acclimated Siberian population. Specifically, determining the metabolic
response (change in energy expenditure and onset of shivering thermogenesis) to
the whole- body cold exposure in both the Siberian population and our proposed
Western European population will have important implications to the research
line investigating the effects of cold exposure on glucose metabolism. For
example, if the metabolic response to the matched cold exposure is blunted or
non-existent after generations of cold acclimation, then one type of cold
exposure may not be effective for all individuals.

To compare the effect of cold exposure on energy expenditure in a population of
adults of Western European origin with adults living in Siberia

The research involving the Siberian population has already been completed in
Siberia in January 2020. We will now replicate the same measurements with a
Western European population. A design combining observational and
quasi-experimental methods will be applied. Each participant will attend the
university on 3 occasions. The first visit will be a screening, lasting
approximately 1 hour. During the next visit a cold-induced vasodilation test of
the finger will be performed, along with attaching skin temperature sensors and
a physical activity monitor for daily living measurements, this visit will last
approximately 1 hour 30 min. The final visit will involve a cold exposure test,
with the visit lasting approximately 3 hours.

During the first test day (second visit) a cold-induced vasodilation (CIVD)
test of the finger will be performed. Cold-induced vasodilation is a mechanism
that may prevent the occurrence of local cold injuries (Daanen, 2003). The CIVD
reaction measures the cold-protection blood perfusion response to cold. During
the test, the participant*s middle finger is immersed in ice water for 30 min.
The magnitude of the CIVD reaction is measured by the skin temperature response
during the cold exposure. Additionally, participants will be attached with skin
temperature sensors and a physical activity monitor for monitoring their
daily-living for 6 days.
During the final visit a whole-body cold exposure test will be performed.
Subjects will be exposed to air temperature of ~9°C, for which the
cold-exposure duration will be a maximum of 1 h.

* The cold finger test and whole-body cold exposure are likely to be
uncomfortable.
* During the whole-body cold test, the participant will likely experience
shivering, which may feel uncomfortable.
* During the whole-body cold test, men will wear shorts and women will wear
shorts and a t-shirt.
* The fingertip capillary blood sample involves a pinprick to the fingertip
* Because the skin temperature sensors are attached for a long duration (6
days) this may cause some irritation. If skin irritation does occur then it is
advised to remove the temperature sensor and replace in a location 2-3
centimetres away from the original location.

This study will provide more insight into the effects of cold exposure on
energy metabolism and may contribute to future research in this area regarding
thermoregulation and the treatment of metabolic disease.