Immune and hormonal reactions of the body of the participants in the three-week Arctic route

Introduction. Due to the ongoing active economic and scientific development of the Arctic, interest in the study of adaptation and preservation of human health during stay and work in high latitudes remains relevant.

The study aims to identify the dynamics of saliva hormones, the sorption activity of the epithelium of the oral fluid, as well as indicators of cellular immunity of participants in a three-week Arctic route.

Materials and methods. Scientists have examined 39 participants of the Arctic Floating University expedition: 26 women and 13 men aged 30 to 52 years (Me=23 years). Morning saliva was collected at the beginning, in the middle and at the end of the 21-day route. The researchers determined the levels of cortisol and testosterone by enzyme immunoassay, and determined the activity of the epithelium in the sediment by microscopy, estimating the average number of microbial bodies on the surface of 100 squamous epitheliocytes. Blood sampling was carried out at the beginning and at the end of the expedition. The experts determined the number of white blood cells in Goryaev's chamber, and they calculated the leukocyte formula in blood smears.

Results. The maximum concentrations of cortisol at the beginning of the flight in men (21.3 nmol/L) and women (23.6 nmol/L) decrease by 4 and 3.2 times in the middle, respectively, and by the end of the route they are 7.4 and 13.5 nmol/l. Testosterone levels significantly increased in the middle of the route by 2.4 times in men (1.72 versus 0.73 nmol/L) and 6 times in women (0.26 versus 0.05 nmol/L) and remained elevated by the end of the expedition. The testosterone/cortisol index increases 10 times in men and 13 times in women in the middle of the route, and its values are 8 and 10 times higher at the end of the route than at the beginning. The sorption activity of the epithelium decreases slightly in the middle of the route (p=0.071). By the end of the expedition, the men's neutrophil-lymphocyte index decreased (2.36 versus 3.78 units, p=0.005) and the Garkavi index increased (0.51 versus 0.27 units, p=0.004).

Limitations. A disproportionately large number of women and the inability to measure the background values of indicators before the route.

Conclusion. The dynamics of hormonal parameters reflect the restructuring of regulatory systems towards anabolic processes, starting from the middle of the route, which contributes to adaptation during the period of intense physical work. There is also a slight decrease in the mechanisms of local immune defense in the middle of the route. Only men had a significant increase in the Garkavi index and a decrease in the neutrophil-lymphocyte index at the end of the route. In women, however, hormonal changes are more pronounced and a greater number of correlations between immune and hormonal parameters have been revealed.

Ethics. The study was conducted in compliance with Ethical standards (Protocol No. 003-25/06 of the meeting of the Ethics Committee dated 06/25/2025).

Contributions:
Elfimova A.E. — concept and design of research, collection and processing of material, writing text;
Patyavina O.I. — collection and processing of material, statistical processing;
Kulikova I.K. — collection and processing of material, statistical processing;
Shtaforov V.A. — material processing, text writing;
Patrakeeva V.P. — research concept and design, editing;
Tipisova E.V. — research concept and design, editing;
Zyabisheva V.N. — material processing, text writing;
Molodovskaya I.N. — material processing;
Alikina V.A. — material processing.

Gratitude. The authors express their gratitude to the Arctic Floating University project and the participants of this study, without whom it would not have taken place.

Funding. The study was carried out with the financial support of the Ministry of Education and Science of the Russian Federation in accordance with the plans of the Federal Research Institute.

Conflict of interest. The authors no conflict of interest.

Received: 12.03.2026 / Accepted: 30.04.2025 / Published: 02.06.2026

1. Elfimova A.E., Patyavina O.I., Zyabisheva V.N., Tipisova E.V. Hormonal parameters of saliva and blood of participants of the 21-day Arctic marine expedition. Russian Journal of Occupational Health and Industrial Ecology [Med. truda i prom. ekol.]. 2025; 65(3): 132–141. https://doi.org/10.31089/1026-9428-2025-65-3-132-141 https://elibrary.ru/zmsujf (in Russian).

2. Hofman L.F. Human Saliva as a Diagnostic Specimen. Am. Soc. Nutr. Sciences. 2001; 131: 1621–1625. https://doi.org/10.1093/jn/131.5.1621S

3. Parakhonsky A.P. Information of hormones of saliva on the functional condition of the endocrine system. Zametki uchenogo [Notes of a scientist]. 2019; 8(42): 35–43 (in Russian). https://elibrary.ru/ukdoyf

4. Chernozub A., Manolachi V. et al. Criteria for assessing the adaptive changes in mixed martial arts (MMA) athletes of strike fighting style in different training load regimes. Peer J. 2022. 1: e13827. https://doi.org/10.7717/peerj.13827

5. Gryaznykh A.V. Index of testosterone/cortisol as an endocrine marker of restorations processes of visceral systems after a muscular pressure. Human. Sport. Medicine. 2011; 237(20): 107–111 (in Russian). https://elibrary.ru/ogybvn

6. Lee Y.H., Chung S.W., Auh Q.S., Hong S.J., Lee Y.A., Jung J. et al. Progress in Oral Microbiome Related to Oral and Systemic Diseases: An Update. Diagnostics (Basel). 2021; 11(7): 1283. https://doi.org/10.3390/diagnostics11071283

7. Mikhalchenko D.V., Makedonova Yu.A., Afanasyeva O.Yu. Immunological blood analysis as a diagnostic factor of psychoemotional stress at a dental appointment. Journal of the Volgograd State Medical University. 2020; 75(3): 70–74. https://doi.org/10.19163/1994-9480-2020-3(75)-70-74 (in Russian).

8. Zahorec R. Ratio of neutrophil to lymphocyte counts-rapid and simple parameter of systemic inflammation and stress in critically ill. Bratisl Lek Listy. 2001; 102(1): 5–14. https://pubmed.ncbi.nlm.nih.gov/11723675/

9. Trushina E.N., Mustafina O.K. On the efficiency of leukocyte indices in the diagnosis of immune disorders in athletes (a review of foreign literature). Human. Sport. Medicine. 2023; 23(4): 40–46. https://elibrary.ru/heebly (in Russian).

10. Russell G., Lightman S. The human stress response. Nature Reviews Endocrinology. 2019; 15(9): 525–534. https://doi.org/10.1038/s41574-019-0228-0

11. Brownlee K.K., Moore A.W., Hackney A.C.. Relationship between circulating cortisol and testosterone: influence of physical exercise. J. Sports Sci. Med. 2005; 4(1): 76-83. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880087/

12. Wood R.I., Stanton S.J. Testosterone and sport: current perspectives. Horm Behav. 2012; 61(1): 147–155. https://doi.org/10.1016/j.yhbeh.2011.09.010

13. Berkovskaya M.A., Elmurzaeva A.A., Edaev A.L.A, Selakhov T.Yu., Tokaev H.M., Gurova I.D. The impact of physical exercise on the endocrine system in men: A review. Consil. med. 2024; 26(4): 263-268 (in Russian). https://doi.org/10.26442/20751753.2024.4.202697

14. Moraes M.M., Bruzzi R.S., Martins Y.A.T., Mendes T.T., Maluf Ch.B., Ladeira R.V.P. et al. Hormonal, autonomic cardiac and mood states changes during an Antarctic expedition: From ship travel to camping in Snow Island. Physiol. Behav. 2020; 224: 113069. https://doi.org/10.1016/j.physbeh.2020.113069

15. Zyryanov B.N., Sokolova T.F. General and local immunity in the indigenous and immigrant population of the Far North. Scientific Bulletin of Yamal-Nenets Autonomous District. 2021; 113(4): 88–105. https://doi.org/10.26110/ARCTIC.2021.113.4.006 (in Russian).

16. Shtaborov V.A., Levanyuk A.I. Interaction of General and local immune reactions of the streets, born and living in the North. Human ecology; 2010; 10: 42–46. https://elibrary.ru/mvgoub (in Russian).

17. Lysenko I.D., Pupkov A.A., Plaksin K.V., Rantsev M.A. Prognostic value of leukocyte indices in acute severe pancreatitis. «Aktual'nye voprosy sovremennoj medicinskoj nauki i zdravoohraneniya». In: Collection of articles from the V International (75th All-Russian) Scientific and Practical Conference. Vol. 3. Yekaterinburg; 2020: 719–725. https://elibrary.ru/qaqxgd (in Russian).

18. Garkavi L.Kh., Kvakina E.B., Kuz’menko T.S. Antistress reactions and activation therapy. Moscow: Imedis Publ.; 1998 (in Russian).