Sex differences in stress and immune responses during confinement in Antarctica

• Published in: Biology of Sex Differences
• Main Authors: C. Strewe, D. Moser, J.-I. Buchheim, H.-C. Gunga, A. Stahn, B. E. Crucian, B. Fiedel, H. Bauer, P. Gössmann-Lang, D. Thieme, E. Kohlberg, A. Choukèr, M. Feuerecker
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2019
• Subjects: Sex differences; Neuroendocrine response; Immunity; Extreme environment; Antarctica; Confinement; Medicine; R; Physiology; QP1-981; Antarctic; Neumayer; Antarc*
• Online Access: https://doi.org/10.1186/s13293-019-0231-0; https://doaj.org/article/18112b880f6942c997eff20ac8bd262c

Abstract Background Antarctica challenges human explorers by its extreme environment. The effects of these unique conditions on the human physiology need to be understood to best mitigate health problems in Antarctic expedition crews. Moreover, Antarctica is an adequate Earth-bound analogue for long-term space missions. To date, its effects on human physiology have been studied mainly in male cohorts though more female expeditioners and applicants in astronaut training programs are selected. Therefore, the identification of sex differences in stress and immune reactions are becoming an even more essential aim to provide a more individualized risk management. Methods Ten female and 16 male subjects participated in three 1-year expeditions to the German Antarctic Research Station Neumayer III. Blood, saliva, and urine samples were taken 1–2 months prior to departure, subsequently every month during their expedition, and 3–4 months after return from Antarctica. Analyses included cortisol, catecholamine and endocannabinoid measurements; psychological evaluation; differential blood count; and recall antigen- and mitogen-stimulated cytokine profiles. Results Cortisol showed significantly higher concentrations in females than males during winter whereas no enhanced psychological stress was detected in both sexes. Catecholamine excretion was higher in males than females but never showed significant increases compared to baseline. Endocannabinoids and N-acylethanolamides increased significantly in both sexes and stayed consistently elevated during the confinement. Cytokine profiles after in vitro stimulation revealed no sex differences but resulted in significant time-dependent changes. Hemoglobin and hematocrit were significantly higher in males than females, and hemoglobin increased significantly in both sexes compared to baseline. Platelet counts were significantly higher in females than males. Leukocytes and granulocyte concentrations increased during confinement with a dip for both sexes in winter whereas ...