The influence of day length on chronotype and sleep variations during an overwinter in Antarctica: the effect of extreme photoperiod on circadian entrainment

TORTELLO, CAMILA; FOLGUEIRA, AGUSTÍN; LÓPEZ, JUAN MANUEL; DIDIER GARNHAM, FEDERICO; SALA LOZANO, ESTEFANÍA; RIVERO, MARÍA SOLEDAD; SIMONELLI, GUIDO; VIGO, DANIEL E.; PLANO, SANTIAGO

Simposio; XVII Latin American Symposium on Chronobiology; 2023

Chronotype is a reliable biomarker for studying the influence of external zeitgebers on circadianentrainment. Assessment of chronotype variation in participants exposed to extreme photoperiods may be useful to investigate how changes in light-dark cycle modulate the circadian system. This study aimed to longitudinally assess chronotype variations and sleep variables throughout a year at Belgrano II Argentine Antarctic station. A sample of 82 participants completed the Munich Chronotype Questionnaire (MCTQ) during March, May, July, September and November. Hierarchical linear modeling was performed to characterize the seasonal modulation of chronotype and sleep variations considering the influence of day length. The main results showed a delay in chronotype (p< .001) and social jetlag (p< .001) during the polar night, highlighting the influence of social cues and the impact of the lack of natural light on circadian rhythms.