Blood oxidative stress markers in the 32nd Bulgarian Antarctic expedition participants

Antarctic expeditions are associated with significant stress for participants related to long journeys, work in adverse environmental conditions, and social contact changes resulting in oxidative stress (OS) at the molecular level. This study aimed to evaluate the blood serum OS of the participants in the 32nd Bulgarian Antarctic Expedition (2023-2024) and related trace elements iron, copper, zinc, and selenium concentrations, lipid profile, and blood parameters. Blood parameters and trace element concentrations were measured in a clinical laboratory. OS indicators were measured spectrophotometrically using kits. The results showed decreased antioxidant enzyme activities and increased glutathione concentration after the expedition in the blood serum from both females and males. No statistical differences in the values of OS parameters between males and females were observed. However, the mean serum total antioxidant capacity after the expedition in males was two times higher than in females. In males, a statistically significant lower erythrocyte sedimentation rate (p<0.05), ferritin (p<0.001), and zinc (p<0.01) levels, catalase (p<0.001) and superoxide dismutase (p<0.05) activities were observed after the expedition. No correlation between enzyme activities and the studied trace element concentrations was found. In conclusion, it can be assumed that the expeditioners’ OS was higher before the expedition, likely because of psychological and physical stress related to overcoming preparation and logistics problems. After the expedition, OS has subsided. In order to maintain good health and increase physical fitness, it could be recommended that polar expeditioners receive dietary supplements, micronutrients, and vitamins in the setting of rational nutrition, especially before an expedition.