Relocation to circumpolar regions exposes people to extreme climatic conditions and a changed psychosocial environment. The aim of this work was to assess, using meta-analysis, changes in several biochemical and physiological parameters in polar expedition participants. We selected 72 publications from scientific literature databases dedicated to changes in biochemical and physiological parameters in people during adaptation in the circumpolar zone, including 53 studies in Antarctica and 19 in the Arctic. Of the selected studies, 35 involved expedition members overwintering in Antarctica. In general, to date, there are significantly more high-quality studies on Antarctica that could be included in the meta-analysis than on the Arctic. The conducted meta-analysis showed that during the first months of adaptation in the coastal zone of Antarctica, people experience an increase in norepinephrine levels. Cortisol levels were increased by 0.17 µg/dL (p = 0.02) in saliva during the first months of adaptation and by 6.2 µg/dL (p < 0.00001) in blood during wintering, which may indicate chronic stress. TSH levels tended to increase during wintering (by an average of 0.25 µU/mL, p = 0.01), T4 levels were decreased during the first months of adaptation (by an average of 12.89 nmol/L, p < 0.00001), and fT4 levels were lower than baseline by 1.37 pmol/L (p = 0.05) during the first months of adaptation and by 1.95 pmol/L (p < 0.00001) during wintering. Meta-analysis showed no significant change in fT3 levels. The meta-analysis did not reveal any signs of inflammation or immunosuppression in the polar explorers. On the contrary, there were signs of immune activation, as indicated by an increase in IL-2 and IgA levels. Participants typically showed a slight increase in body weight during the polar expedition. Data on blood pressure (BP) changes showed high heterogeneity, which can be explained by varying degrees of adaptation and different living conditions. In people at high-altitude Antarctic stations, an increase in the level of norepinephrine (in urine by an average of 25 µg, p = 0.0002) and heart rate (HR) (by an average of 11.9 beats/minute, p = 0.03) was observed in the first months of adaptation, as well as an increase in hematocrit (by an average of 7%, p < 0.00001), hemoglobin (by an average of 3.9 g/dL, p < 0.00001), red blood cells (by an average of 1.2 1012/L, p < 0.00001) during the entire period of the expedition. Our meta-analysis showed that changes in biochemical and physiological parameters in people adapting to the circumpolar zone differ in many respects from seasonal changes. Moving to the circumpolar region is associated with physiological and psychological stress. Shifts in polar explorers’ metabolism are caused by both meteorological conditions and emotional stress.
Kuzmenko et al. (Sun,) studied this question.