Effects of Social Isolation on Human Sleep and Chronotype During the COVID-19 Pandemic

Abstract

The lockdown enforced by several countries due to the COVID-19 pandemic induced severe changes in light exposure and the social factors related to daily routine tasks. We hypothesized that human sleep and daily rhythms should change accordingly, tending to later sleep timing and later chronotype, longer sleep duration and a better alignment between social and internal cues. We compared sleep- and chronotype-related parameters in the same subjects (n=1293) under a control situation and the mandatory COVID-associated isolation. Our results show that both timing and duration of sleep are profoundly affected (mostly during weekdays), without changes in sleep quality. Several factors modulated this main effect, including age and work status. Subjects sleep longer and later under isolation, better aligned with their internal time; however, the significant delay in sleep timing suggests that these effects could turn into even later chronotypes and, eventually, desynchronization which would negatively affect human performance and health.

Funding: This research was supported by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Quilmes and Agencia Nacional de Promoción Científica y Tecnológica (PICT-20173487). M.J.L is funded by CONICET and Universidad Nacional de Quilmes. M.S. is sponsored by CONICET and the James S. McDonnell Foundation 21st Century Science Initiative in Understanding Human Cognition Scholar Award. D.A.G. is funded by CONICET, FONCyT and Universidad Nacional de Quilmes.

Conflict of Interest: There are not competing interests.

Ethical Approval: The original study was approved by the institutional Ethical Committee of the Universidad Nacional de Quilmes (Verdict #2/2017) and a modification was added and approved to make the second survey during the mandatory isolation (Verdict #1/2020). All subjects gave their informed consent to participate on each phase after the nature and implications of the study were explained. The study was conducted according to ethical recommendations for human chronobiological research.

Keywords: sleep, chronotype, social isolation, COVID-19 pandemic