title: Hot heads & cool bodies: The conundrums of human brown adipose tissue (BAT) activity research.
abstract: Brown adipose tissue is able to increase energy expenditure by converting glucose and fatty acids into heat. Therefore, BAT is able to increase energy expenditure and could thereby facilitate weight loss or at least weight maintenance. Since cold is a strong activator of BAT, most prospective research is performed during cold to activate BAT. In current research, there are roughly two methods of cooling. Cooling by lowering ambient air temperature, which uses a fixed temperature for all subjects and personalized cooling, which uses cooling blankets or vests with temperatures that can be adjusted to the individual set point of shivering. These methods might trigger mechanistically different cold responses and hence result in a different BAT activation. This hypothesis is underlined by two studies with the same research question (difference in BAT activity between Caucasians and South Asians) one study found no differences in BAT activity whereas the other did found differences in BAT activity. Since most characteristics (e.g. age, BMI) were similar in the two studies, the best explanation for the differences in outcomes is the use of different cooling protocols. One of the reasons for differences in outcomes might be the sensory input from the facial skin, which might be important for the activation of BAT. In this review we will elaborate on the differences between the two cooling protocols used to activate BAT.
authors.affiliation: Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: l.bahler@amc.uva.nl.
authors.forename: Lonneke
authors.initials: L
authors.lastname: Bahler
authors.affiliation: Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Frits
authors.initials: F
authors.lastname: Holleman
authors.affiliation: Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Booij
authors.affiliation: Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Joost B
authors.initials: JB
authors.lastname: Hoekstra
authors.affiliation: Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Hein J
authors.initials: HJ
authors.lastname: Verberne
mesh_terms: D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging* / Q000502:physiology*; D001835:Body Weight; D003080:Cold Temperature; D004734:Energy Metabolism / Q000502:physiology; D019788:Fluorodeoxyglucose F18; D006801:Humans; D049268:Positron-Emission Tomography
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Air cooling; Brown adipose tissue; Cold exposure; Cooling blanket; Head