Summary
Living under an official time zone misaligned with solar time (as in western Spain, GMT+1 vs. natural GMT0) reduces circadian robustness and increases internal desynchronization compared to populations whose official time matches their longitude (Portugal). These findings suggest that lighting and scheduling environments should account for solar time alignment, as social time misalignment alone—even in retired populations without work obligations—can disrupt circadian health.
Key Findings
- Both Spanish and Portuguese elderly populations slept 7–8 hours, but circadian robustness (interdaily stability and relative amplitude) was significantly greater in Portugal, especially during weekdays.
- Greater internal desynchronization (body temperature vs. motor activity, and body temperature vs. light exposure) was found in the Spanish cohort living under misaligned official time.
- Once corrected for GMT0, meal times occurred later in Spain than Portugal, with the difference increasing as the day progressed, suggesting a possible link between delayed meal/bed timing and internal circadian desynchronization.
- Results indicate that official time misalignment with geographical/solar time has measurable deleterious effects on the circadian system even in populations free from occupational schedules.
Categories
Sleep & Circadian Health: Compares circadian robustness and sleep patterns between populations living in misaligned vs. aligned official time zones, demonstrating the impact of social clock discrepancy on circadian rhythmicity.
The Science of Light: Examines desynchronization between body temperature, motor activity, and light exposure as a function of official time misalignment with solar time.
Author(s)
MÁ Bonmatí-Carrión, E Casado-Ramirez
Publication Year
2022
Number of Citations
4
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