Sleep at extreme latitudes: examining the differences between Antarctic and arctic environments

Sleep problems in Antarctic crews remain one of the main issues in expeditions. Several studies have documented poor subjective sleep quality, an increased sleep fragmentation, a decrease in slow wave sleep (i.e., the restoring part of sleep during night) as well as dysregulated secretion of melatonin and cortisol (i.e., the two important sleep hormones that inform us about circadian adaptation). One of the most recurrent clarifying factors in the literature for these sleep issues is the lack of normal photoperiodicity (i.e., the day-night alternance over an epoch of 24 hours) due to the interaction of latitude and seasonality.

Based on the state-of-the art, and the current pending hypotheses, we will compare the impact of latitude and seasonality on sleep health and circadian rhythms in Antarctic expeditioners (limited lived experience with living in isolated regions) versus Arctic inhabitants (life-long or intergenerational lived experience). We will use existing data of male and female expeditioners that we collected (and are still collecting) during campaigns in Halley and Dumont d’Urville (two stations at sea-level, no hypoxia, but different landscape) and match them in terms of latitude, age, landscape, and psychosocial background to new data that we will collect of male and female Arctic inhabitants.
Research Objective 1. To examine the impact of latitude versus lived experience on sleep and circadian rhythms in male subjects.
Research Objective 2. To examine gender effects in Arctic inhabitants.
Research Objective 3. Further exploration of a gender-experience effect.
Research Objective 4. The integration: a Bayesian Network Analysis.

This project is funded by the Belgian Federal Science Policy (BELSPO) under contract RT/23/LATTITUDE