Extreme Living Conditions in Antarctica and Their Impact on the Cardiovascular System

pp. 121-130

Abstract

Background: Antarctica is one of the most challenging places to overwinter due to its meteorological characteristics, extreme light patterns, limited social interaction, and isolation.  To analyze cardiovascular function under conditions of confinement, circadian disruption, and prolonged isolation in a low-pollution area.

Methods: Observational, analytical, and longitudinal study in a group of 23 trained and healthy military personnel at the Argentinean Belgrano II Base in Antarctica. Body temperature, environmental and outdoor temperature were recorded. Abdominal waist circumference, body weight control and body composition were determined using bioelectrical impedance. The results of the exercise stress test and the 24-hour Holter ECG were recorded.
Measurements were made monthly for 12 months, including a baseline period, polar continuous darkness months, and continuous daylight months (confinement). Each individual was self-controlled. The baseline results were compared with those from the darkness and daylight periods and the darkness and daylight periods were compared with each other. Measurements were made between January 2023 and January 2024.

Results: The participants were trained males, with a mean age of 34.7 ± 5.1 years (range: 27-43), all exposed to the same diet, physical demands, and ambient temperature. No significant differences were observed in body composition parameters. The analysis showed a significant decrease in the heart rate (HR), systolic and diastolic blood pressure (BP) at rest, during maximal effort and during recovery on the exercise stress test, during the periods of darkness and daylight compared to baseline.
A similar trend was observed in the Holter ECG recordings, which showed significant changes in HR variability in the confinement phase compared to baseline. No differences were detected between the periods of darkness and daylight.

Conclusions: This behavior reflects autonomic nervous system activity on cardiac function and suggests an increased neurovegetative pattern, predominantly vagal. The implications of this study are relevant to the fields of healthcare, occupational performance in polar environments and space exploration.