Research

Lübeck Researchers Decipher the Mechanisms of Heat Intolerance in Hyperthyroidism

Activation of brown adipose tissue could positively influence obesity or type II diabetes.

<STRONG/>Hyperthyroidism is a common condition that is often associated with increased body temperature and an intolerance of warm environments. Up to now, however, there has been insufficient understanding of how the symptoms occur. Researchers at the University of Lübeck’s Center of Brain, Behavior and Metabolism (CBBM) have now deciphered the underlying mechanisms of the condition in a mouse model.

“The increased body temperature in hyperthyroidism is a combination of several effects of thyroid hormones. They increase the basal metabolic rate in muscles, which produces more heat. At the same time, they produce a fever-like effect in the brain, leading to an increase to the body's core temperature,” explains Prof. Dr. Jens Mittag, who leads the study. The lead author of the publication, Kornelia Johann, adds, “Our work also shows that hyperthyroidism contributes to the creation of brown or beige adipose tissue, which is interesting from a therapeutic perspective, as it can convert excess fat into heat. However, this tissue was not active and did not contribute to the symptoms of hyperthyroidism.”

These new insights were gained in collaboration with researchers from Santiago de Compostela, Amsterdam, Cambridge, Hamburg, and Cologne, and funded by, among others, the German Research Foundation (DFG) as part of its Priority Programme SPP1629 Thyroid TransAct. The findings will now be published in the renowned journal “Cell Reports”. The researchers now want to discover how the brown fat induced by the thyroid hormone can be activated so as to positively influence metabolic diseases such as obesity or type II diabetes.

For their research results, Kornelia Johann received the Von Basedow Award 2019 from the German Society for Endocrinology in Göttingen on 22 March.

Publication

Kornelia Johann, Anna Lena Cremer, Alexander W. Fischer, Markus Heine, Eva Rial Pensado, Julia Resch, Sebastian Nock, Samuel Virtue, Lisbeth Harder, Rebecca Oelkrug, Mari-ana Astiz, Georg Brabant, Amy Warner, Antonio Vidal-Puig, Henrik Oster, Anita Boelen, Miguel López, Joerg Heeren, Jeffrey W. Dalley, Heiko Backes, Jens Mittag: “Thyroid Hormone Induced Browning of White Adipose Tissue Does Not Contribute to Thermogenesis and Glucose Consumption”, Cell Reports, online 11 June 2019.