Until the development of artificial light sources, life evolved under a cyclic environment where the sun was the main source of light. Thus, living organisms developed endogenous timing mechanisms to orchestrate temporal coordination of their physiology with their environment, a task performed by the circadian system (CS). Nocturnal blue light exposure, the most efficient to suppress melatonin secretion is currently increasing because the proliferation of energy-efficient lighting (LEDs) as well as a wide spread of electronics devices with screens, contributing to the disorganization of our circadian system (chronodisruption). Thus, the main objective of this study was to analyze the influence of nocturnal blue light exposure from electronic devices on circadian system health evaluated by circadian ambulatory monitoring (CAM).

To this, 12 healthy young subjects were recruited and their light exposure, skin wrist temperature, activity and body position rhythms were recorded, while maintaining their habitual nocturnal use of electronic devices (during 7 days) and after 3 days of avoiding this use during that period. CAM was performed with 3 data loggers: Ibuttom (ThermoChron®, IDC S.A., Spain), Hobo (HOBO® Pendant Temperature/Light) and Hobo (Hobo® Pendant G Acceleration Data Logger).
This novel pilot study demonstrated that avoiding light-emitting diodes backlit screen exposure phase advances the sleep wake pattern, and increases the Circadian Function Index (CFI) for skin temperature, activity, body position and composite TAP variable patterns, indicating an augmentation in circadian robustness.

In conclusion, the results show a clear improvement in the biological variables analyzed during the intervention phase restricting electronic devices use during the night period, evidencing their cronodisruptive effects.