Mette Malene Motzfeldt Jensen's PhD defense

The Department of Clinical Medicine, Aalborg University and Ilisimatusarfik are pleased to invite to PhD defense by Mette Motzfeldt Jensen, MD, who will defend her thesis entitled: Cold Metabolism and Brown Adipose Tissue Activation in Inuit and Danes.

• When: Monday 8th of December 2025 at 13.00 (Greenlandic time)

• Where: the auditorium at Ilisimatusarfik

• Live stream: Microsoft Teams (ID: 379 983 295 339 33 - password: 5dN6WA3A)

After the defense there will be a reception - all are welcome.

About the PhD thesis

This PhD project investigates the metabolic effects of cold exposure with a particular focus on brown adipose tissue (BAT) in Greenlanders and Danes. BAT is a specialised fat tissue that produces heat by oxidising fat and glucose. It is considered protective against obesity and metabolic diseases, and cold is the most potent natural stimulus for activating this tissue.

Greenlanders constitute a population with well-documented genetic adaptations to the extreme Arctic environment. We hypothesised that Greenlanders, due to evolutionary cold adaptation and habitual exposure to low temperatures, would have greater BAT volume and activity compared with Danes.

The project comprises a literature review, an intervention study assessing thyroid hormone responses following β-blocker administration among East Greenlandic hunters, and a comparative clinical trial examining physiological responses in Greenlanders and Danes during a controlled two-hour cold exposure. BAT activity was quantified using PET/CT imaging and assessed indirectly via infrared thermography, while repeated blood sampling captured changes in metabolic markers and thermogenic hormones.

The findings reveal distinct physiological responses to cold, including differences in BAT activation, thyroid hormone dynamics, and metabolic markers. Collectively, the results suggest that Greenlanders have developed a physiological preparedness for cold, enabling rapid heat production while maintaining glucose and lipid homeostasis despite increased metabolic demands.

These insights enhance our understanding of human cold adaptation and may support future research into metabolic health, and the potential therapeutic applications of BAT activation.