Glucocorticoids modulate human brown adipose tissue thermogenesis in vivo

Abstract

IntroductionBrown adipose tissue (BAT) is a thermogenic organ with substantial metabolic capacity and has important roles in the maintenance of body weight and metabolism. Regulation of BAT is primarily mediated through the β-adrenoceptor (β-AR) pathway. The in vivo endocrine regulation of this pathway in humans is unknown. The objective of our study was to assess the in vivo BAT temperature responses to acute glucocorticoid administration.MethodsWe studied 8 healthy male volunteers, not pre-selected for BAT presence or activity and without prior BAT cold-activation, on two occasions, following an infusion with hydrocortisone (0.2 mg.kg− 1.min− 1 for 14 h) and saline, respectively. Infusions were given in a randomized double-blind order. They underwent assessment of supraclavicular BAT temperature using infrared thermography following a mixed meal, and during β-AR stimulation with isoprenaline (25 ng.kg fat-free mass− 1.min− 1 for 60 min) in the fasting state.ResultsDuring hydrocortisone infusion, BAT temperature increased both under fasting basal conditions and during β-AR stimulation. We observed a BAT temperature threshold, which was not exceeded despite maximal β-AR activation. We conclude that BAT thermogenesis is present in humans under near-normal conditions. Glucocorticoids modulate BAT function, representing important physiological endocrine regulation of body temperature at times of acute stress.

Non-adrenergic control of lipolysis and thermogenesis in adipose tissues

“…Administering healthy male subjects with three doses of prednisolone (the first dose was administered 24 h before visiting the research facility) had no effect on basal BAT activity; however, PET and infrared thermography of skin temperature in the supraclavicular region revealed that cold-induced glucose uptake in BAT and skin temperature were enhanced by prednisolone (Ramage et al, 2016). An independent study using infrared thermography demonstrated that infusing healthy male subjects with hydrocortisone for 24 h had no effect at room temperature; however, a cold-induced increase in skin temperature of the supraclavicular region was enhanced (Scotney et al, 2017). Results obtained in cell culture are in line with these observations.…”

Infrared Thermography for Estimating Supraclavicular Skin Temperature and BAT Activity in Humans: A Systematic Review

“…The first study to use IRT to estimate SST was performed in 2011 . Ten studies were then published between 2011 and 2016 , six in 2017 , six in 2018 , and one until April 2019 .…”

“…The first study to use IRT to estimate SST was performed in 2011 (24). Ten studies were then published between 2011 and 2016 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34), six in 2017 (35)(36)(37)(38)(39)(40), six in 2018 (16,(41)(42)(43)(44), and one until April 2019 (45).…”

“…Some 56% of these individuals were from four studies (n = 164, n = 102, n = 88, n = 86) (24,31,43,44) (Table 1). Twelve of the selected twenty-four studies included both sexes (24,26,28,29,31,32,37,(41)(42)(43)45,46), three involved only females (27,33,44), and nine involved only males (16,25,30,(34)(35)(36)(38)(39)(40). One study took into account the phases of the menstrual cycle (32).…”

“…According to the PEDro scale criteria, 8.3% (n = 2) (24,25) of the studies were of low quality, 62.5% (n = 15) (20,26,27,30,31,33,(36)(37)(38)(39)41,43,44) of medium quality, and 29% (n = 7) (32,34,35,40,42,45,46) of high quality ( Table 2). The criteria least satisfied by the different studies were those of items 2 and 3 regarding allocation and 5, 6, and 7 regarding the blinding process.…”