Intermittent cold exposure improves glucose homeostasis despite exacerbating diet‐induced obesity in mice housed at thermoneutrality

Abstract

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Cold Exposure Drives Weight Gain and Adiposity following Chronic Suppression of Brown Adipose Tissue

“…Importantly, it was recently demonstrated that BAT from obese mice, housed chronically at thermoneutrality closely resembles human BAT [4]. This model of 'physiologically humanised BAT' is now thought to represent the best choice for studying the physiology of this key metabolic tissue and it has recently been shown that intermittent cold exposure of thermoneutrally housed animals exacerbates diet-induced obesity [5]. Here, we extend this recent work by raising animals at thermoneutrality, on an obesogenic diet from weaning.…”

“…Rats are also more susceptible to weight gain, and fat accumulation when reared in the cold (18 • C vs. 30 • C), an effect which persists when housed at a common temperature [22]. More recently, it was demonstrated that ICE increases weight gain, largely due to increases in adiposity, in both male and female mice housed at thermoneutrality and fed a diet high in fat [5]. Despite no effect on circulating NEFA or insulin concentrations, ICE increased lipid deposition in hepatocytes and circulating leptin whilst decreasing circulating triglycerides.…”

Activating thermogenesis to combat obesity: hot topic or cold front?

“…In a recent issue of The Journal of Physiology , McKie et al . (2022) tested the effect on obesity of activating thermogenesis through repeated short bouts of cold exposure among physiologically ‘humanized’ mice. First, thermoneutral‐housed mice were fed either a low‐fat control or high‐fat diet to induce obesity.…”

“…Because the translational relevance for humans of such paradigms has been questioned, McKie et al . (2022) addressed this concern using an intermittent cold exposure (ICE) protocol, in which mice were briefly removed from thermoneutrality and placed for 1 h at 4°C, five times per week.…”

“…Given that a cold exposure rapidly increased feeding without altering circulating lipids or liver energy stores, McKie et al . (2022) concluded that ICE‐induced hyperphagia is a sensory‐evoked behaviour that takes place in anticipation of increases in energy demand, rather than a compensatory response to depleted energy stores. It is important to note that rapidly placing mice in the cold will just as quickly activate muscle shivering for thermogenesis; only after prolonged exposure does BAT become the primary source of heat (Cannon & Nedergaard, 2004).…”