Glucose is the primary energy source for many physiological responses in mammals, including thermoregulation, which requires a significant amount of energy. This process allows homeotherms to maintain a stable body temperature within a narrow range despite fluctuations in ambient temperature. Although thermoregulation is known to be closely linked to glucose metabolism, the precise interaction between these two processes remains unclear, partly because of the tight regulation of body temperature. To investigate the relationship between body temperature and glucose metabolism, we utilized a hypothermogenetic model called Qrfp-neuron-Induced Hypothermia and Hypometabolism (QIH).
This model allows for the reversible induction of hypothermia, lowering core body　temperature to as low as 21-22oC. The QIH mice exhibited a diabetes-like glucose　metabolism, characterized by hyperinsulinemia and insulin resistance. Interestingly, this QIH-induced glucose hypometabolism was reversed to normal levels when body temperature was raised by placing the mice in a warm environment. In contrast to normal mice, in which warm ambient temperature reduces energy expenditure due to decreased thermogenesis, QIH mice displayed increased energy expenditure under warm conditions. These findings demonstrate a distinct effect of ambient and body temperature on glucose metabolism, providing a new perspective for investigating energy homeostasis in mammals.