Short-term Cold Acclimation Recruits Brown Adipose Tissue in Obese Humans.

Recruitment of brown adipose tissue (BAT) has emerged as a potential tool to combat obesity and associated metabolic complications. Short-term cold acclimation has been shown not only to enhance the presence and activity of BAT in lean humans but also to improve the metabolic profile of skeletal muscle to benefit glucose uptake in patients with type 2 diabetes. Here we examined whether short-term cold acclimation also induced such adaptations in 10 metabolically healthy obese male subjects.

Supraclavicular skin temperature and BAT activity in lean healthy adults.

The 'gold standard' for measuring brown adipose tissue (BAT) in humans is [(18)F]FDG-PET/CT-imaging. With this technique subjects are exposed to ionizing radiation and are therefore limited in the number of scans that can be performed. We investigated the relation between supraclavicular skin temperatures and BAT activity values using a strictly temperature-controlled air-cooling protocol.

Cold acclimation affects immune composition in skeletal muscle of healthy lean subjects.

Low environmental temperatures have a profound effect on biological processes in the body, including the immune system. Cold exposure coincides with hormonal changes, which may directly or indirectly alter the immune system, even in the skeletal muscle. The aim of the present study was to investigate the effect of cold acclimation on immune composition in skeletal muscle.

Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus.

Cold exposure may be a potential therapy for diabetes by increasing brown adipose tissue (BAT) mass and activity. Here we report that 10 d of cold acclimation (14-15 °C) increased peripheral insulin sensitivity by ∼43% in eight type 2 diabetes subjects. Basal skeletal muscle GLUT4 translocation markedly increased, without effects on insulin signaling or AMP-activated protein kinase (AMPK) activation and only a minor increase in BAT glucose uptake.

Serum FGF21 levels are associated with brown adipose tissue activity in humans.

The obesity pandemic has spurred a need for novel therapies to prevent and treat metabolic complications. The recent rediscovery of brown adipose tissue (BAT) in humans made this tissue a possible therapeutic target, due to its potentially substantial contributions to energy homeostasis. Fibroblast growth factor 21 (FGF21) has been identified as a facilitator of cold-induced thermogenesis in humans.

Cold-activated brown adipose tissue in human adults: methodological issues.

The relevance of functional brown adipose tissue (BAT) depots in human adults was undisputedly proven approximately seven years ago. Here we give an overview of all dedicated studies that were published on cold-induced BAT activity in adult humans that appeared since then. Different cooling protocols and imaging techniques to determine BAT activity are reviewed.

Cold acclimation recruits human brown fat and increases nonshivering thermogenesis.

In recent years, it has been shown that humans have active brown adipose tissue (BAT) depots, raising the question of whether activation and recruitment of BAT can be a target to counterbalance the current obesity pandemic. Here, we show that a 10-day cold acclimation protocol in humans increases BAT activity in parallel with an increase in nonshivering thermogenesis (NST). No sex differences in BAT presence and activity were found either before or after cold acclimation.

Brown adipose tissue activity after a high-calorie meal in humans.

Background: Studies in rodents have shown that brown adipose tissue (BAT) is activated on food intake, thereby reducing metabolic efficiency.

Objective: The current study investigated whether a single high-calorie, carbohydrate-rich meal activates BAT in lean human adults.

Design: BAT activity was studied in 11 lean adult men [age: 23.

Imaging cold-activated brown adipose tissue using dynamic T2*-weighted magnetic resonance imaging and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography.

Objectives: The objective of this study was to explore the use of magnetic resonance imaging (MRI) to identify and quantify active brown adipose tissue (BAT) in adult humans. 2-Deoxy-2-[F]fluoro-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography was used as a reference method to identify active BAT depots and to guide the MRI data analysis.

Materials And Methods: The ethics committee of the institute approved the protocol, and all participants provided written informed consent before participation.

Systemic β-adrenergic stimulation of thermogenesis is not accompanied by brown adipose tissue activity in humans.

Brown adipose tissue (BAT) is currently considered as a target to combat obesity and diabetes in humans. BAT is densely innervated by the sympathetic nervous system (SNS) and can be stimulated by β-adrenergic agonists, at least in animals. However, the exact role of the β-adrenergic part of the SNS in BAT activation in humans is not known yet.