Bérénice Delwiche

Research

Disrupted sleep due to shift work poses significant health and societal challenges. In Belgium, approximately one third of workers function in shift systems, leading to widespread sleep disturbances and fatigue reported by 90% of them. Shift workers are at increased risk of cardiovascular issues, gastrointestinal disorders, mood disturbances, accidents, and economic burdens compared to day workers. Some individuals adapt well to shift work, while others may develop Shift Work Sleep Disorder (SWSD). Understanding individual tolerance to shift work involves various factors such as gender, age, personality, and, crucially, the intricate mechanisms of the circadian timing system (CTS).

The CTS governs our sleep-wake patterns through its phase, amplitude, and period dynamics. While extensive research has focused on phase preferences, amplitude differences have received less attention. Yet, it appears that better adaptation to shift work is associated with a lower subjective circadian amplitude, indicating a nuanced response to the signals from the endogenous CTS. However, past studies have encountered challenges in accurately measuring circadian flexibility, leading to conflicting results.

This deeper understanding of the CTS and its association with individual tolerance to extreme sleep-depriving conditions, such as shift work, holds profound implications.

Supervisor

Prof. Dr. Olivier Mairesse