Sensitivity of the circadian system to evening bright light in preschool-age children

• DOI: 10.14814/phy2.13617
• Publication Date: 2018-03-05T03:02:35Z
• Authors: Lameese D. Akacem; Kenneth P. Wright; Monique K. LeBour...
• Keywords: Bedtime; Light sensitivity

Although the light-induced melatonin suppression response is well characterized in adults, studies examining dynamics of this effect children are scarce. The purpose study was to quantify magnitude evening preschool-age children. Healthy (n = 10; 7 females; 4.3 ± 1.1 years) participated a 7-day protocol. On days 1–5, followed strict sleep schedule. day 6, entered dim light environment (<15 lux) for 1-h before providing salivary samples every 20- 30-min from afternoon until 50-min after scheduled bedtime. 7, subjects remained conditions bedtime, at which time they were exposed bright stimulus (~1000 and then re-entered conditions. Saliva obtained before, during, exposure anchored taken previous evening. We found robust (87.6 10.0%) stimulus. Melatonin levels attenuated termination (P < 0.008). Furthermore, did not return 50% those observed condition 7/10 Our findings demonstrate These have implications understanding role development settling difficulties may serve as experimental evidence support recommendations regarding hygiene practices early childhood.