Light and Dark Management to Mitigate Sleepiness and Fatigue Associated with Night Shift Work: Insights into Circadian Disruption and Sleep Quality

Introduction: Numerous studies indicate that night shift work negatively impacts health and performance. Work during times designated for rest, and sleeping during periods intended for wakefulness, conflicts with human diurnal physiology, which is regulated in part by the circadian clock. This misalignment results in sleep deprivation, increased sleepiness, decreased performance, and impaired health and quality of life for shift workers. Although studies conducted in controlled environments suggest that managing exposure to light and darkness can alleviate these problems, it is necessary to evaluate the effectiveness of such interventions under real-world working conditions.

Methods: We recruited two samples (N = 24 and N = 38) of rotating night-shift workers from two different transportation companies located in the northern Chile. Demographic information such as age, years working night shifts, medication use, commuting times, sleep quality, and quantity were assessed using the Karolinska Sleep Questionnaire and Sleep Diaries. Regression analyses were conducted to evaluate associations between demographic variables and sleep outcomes, specifically examining how these factors influence sleep quality and quantity during night shifts.

Results: Preliminary findings indicate reduced sleep quality among workers from both samples, suggesting widespread circadian disruption. In addition, workers reported substantial commuting times from their homes to their workplace, highlighting an additional factor that may contribute to sleep deficits. Regression analysis revealed a significant positive correlation between years performing night shifts and total sleep hours achieved during night shifts, suggesting adaptive or compensatory mechanisms whose effectiveness increases with experience.

Conclusion: Our study confirms significant sleep disturbances and circadian disruptions among night-shift workers. The observed relationship between years spent working night shifts and sleep duration highlights potential adaptive mechanisms worth further exploration. These insights are crucial for developing targeted interventions to improve night shift workers' health and well-being. Support: The authors would like to thank the CINV and the VRII from Universidad de Valparaíso for their technical support in the execution of this project. We also would like to thank to the Agencia Nacional de Investigación y Desarrollo, Proyecto Idea ID22I10053 (to JE) and Concurso Subvención a la Instalaciónen la Academia 85220042 (to LBG) as our funding sources.

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Artikel online veröffentlicht:
08. Oktober 2025