156 Evening Light-Induced Circadian Phase Shift in Preschool-Aged Children

• DOI: 10.1093/sleep/zsab072.155
• Publication Date: 2021-05-03T10:08:58Z
• Authors: Lauren Hartstein; Lameese Akacem; Cecilia Diniz Behn; Shelby Stowe; Kenneth Wright; Monique LeBourgeois
• Keywords: Bedtime

Abstract Introduction In adults, exposure to light at night delays the timing of circadian clock in a dose-dependent manner with intensity. Although children’s melatonin levels are highly suppressed by evening bright light, sensitivity young is unknown. This research aimed establish an illuminance response curve for phase delay preschool children as result varying intensities hour before bedtime. Methods Healthy (n=36, 3.0 – 4.9 years, 39% males), participated 10-day protocol. For 7 days, followed strict parent-selected sleep schedule. On Days 8-10, in-home dim-light assessment was performed. Day 8, dim onset (DLMO) measured through saliva samples collected 20-30-min intervals throughout until 1-h past habitual 9, were exposed white stimulus (semi-randomly assigned from 5lx 5000lx) their bedtime, and before, during, after exposure. 10, provided 2.5-h bedtime final DLMO assessment. Phase angle entrainment (habitual DLMObaseline) (DLMOfinal computed. Results Final (Day 10) shifted between -8 123 minutes (M = 56.1 +/- 33.6 min; negative value advance, positive delay) compared baseline 8). Raw shift did not demonstrate relationship Rather, we observed robust across all intensities. Conclusion These data suggest preschoolers’ clocks immensely sensitive large range intensities, which may be mechanistically influenced less mature ophthalmologic features (e.g. clearer lenses, larger pupils). With ever-growing use light-emitting devices artificial lighting, well prevalence behavioral problems, these findings inform recommendations parents on effects early childhood. Support (if any) supported funds Eunice Kennedy Shriver National Institute Child Health & Human Development (R01-HD087707).