Photoperiodic stability and distribution of chronotypes in young residents of the North with different organization of activities

Abstract

AIM: To assess individual subjective chronotypic properties in residents of Khanty-Mansiysk under the influence of such biotropic and social stress factors as regular daytime and aperiodically presented shift daytime and nighttime employment. MATERIALS AND METHODS: This study involved students (100 girls and 53 boys) of Khanty-Mansi Autonomous Okrug Yugra with a daily study load and employees of the Ambulance station (31 women and 26 men) in Khanty-Mansiysk, working in shifts. The photoperiodic chronotype stability was studied using the computer program Photoperiodic chronotype stability calculator (registration no. 2019661664) in the form of a mobile application for Android Photoperiodic stability index. RESULTS: The photoperiodic stability of the chronotype in women was: with regular daily employment 3.5 (1.56.0) arb. units, with shift work 1.0 (04.0) arb. units. The photoperiodic stability of the chronotype in men was: with regular daily employment 3.0 (1.04.0) arb. units, with shift work 1.5 (03.0) arb. units. Volunteers with a regular daytime job tended to choose to shift activities to the afternoon and refusing morning activity. In the group with shift work, the proportion of people preferring the morning type of work capacity was higher. In the group with shift and night work, there were no representatives of a definitely morning chronotype among women, and definitely an evening chronotype among men. In the summer season, male and female respondents, regardless of the production regime, showed an increase in the signs of the morning chronotype. CONCLUSION: The production and intersexual features of the chronotypological properties of the inhabitants of the North have been established. With the superposition of extreme climatic and geographical factors and social and production conditions, a general pattern of increased rigidity of the chronotype was recorded. Male and female respondents under different production regimes, when assessing subjective biorhythmic performance in the summer, demonstrated a shift toward the morning chronotype.