Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: Role of light-dark exposure

Key points Shift work is highly prevalent and is associated with significant adverse health impacts. There is substantial inter‐individual variability in the way the circadian clock responds to changing shift cycles. The mechanisms underlying this variability are not well understood. We tested the hypothesis that light–dark exposure is a significant contributor to this variability; when combined with diurnal preference, the relative timing of light exposure accounted for 71% of individual variability in circadian phase response to night shift work. These results will drive development of personalised approaches to manage circadian disruption among shift workers and other vulnerable populations to potentially reduce the increased risk of disease in these populations.