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Updated: Jun 29, 2025
Human Circadian Phenotyping and Diurnal Performance Testing in the Real World
Published on: April 7, 2020
Estimating dim light melatonin onset time in children using delta changes in melatonin
Taisuke Eto1,2,3, Shingo Kitamura1, Akiko Shikano4
1Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8553 Japan.
Insights
This study developed a method to estimate dim light melatonin onset (DLMO) in children using salivary melatonin levels. The mathematical slope method provides a reliable way to determine DLMO, crucial for understanding circadian rhythms.
Area of Science:
- Chronobiology
- Pediatric Sleep Medicine
- Biomarker Analysis
Background:
- Dim light melatonin onset (DLMO) is a key indicator of circadian timing.
- Accurate DLMO estimation is vital for pediatric sleep research and clinical assessment.
- Current methods may require extensive sampling or complex protocols.
Purpose of the Study:
- To develop and validate a mathematical method for estimating DLMO in children.
- To assess the accuracy of DLMO estimation using salivary melatonin concentrations at specific time points.
- To establish a practical approach for DLMO assessment in pediatric populations.
Main Methods:
- Saliva samples were collected from 30 children (mean age 10.2 years) under dim light.
- Melatonin concentrations were measured at multiple time points before and after sleep.
- Mathematical slopes and multiple regression analysis with leave-one-out cross-validation were used for DLMO estimation.
Main Results:
- DLMO estimation using mathematical slopes and regression analysis showed significant accuracy.
- The highest accuracy (ICC=0.726) was achieved using a specific slope calculation at the t20 time point.
- The developed method demonstrated a reliable correlation between estimated and measured DLMOs.
Conclusions:
- A novel mathematical method effectively estimates DLMO in children from limited salivary melatonin samples.
- This approach offers a practical and accurate tool for assessing circadian timing in pediatric research.
- The findings support the use of salivary melatonin slopes for non-invasive DLMO determination.
Abstract:
We aimed to establish a method for estimating dim light melatonin onset (DLMO) using mathematical slopes calculated from melatonin concentrations at three sampling points before and after sleep in children. The saliva of 30 children (mean age ± SD: 10.2 ± 1.3 years old) was collected under dim-light conditions up to six times every hour starting at 17:30 (t17), namely, 18:30 (t18), 19:30 (t19), 20:30 (t20), 21:30 (t21), 22:30 (t22), and 23:30 (t23), in the evening, and at 6:00 (t30) the following morning. We calculated (mathematical slope between melatonin concentrations at t18 and t20, t21 or t22), (the slope between t20, t21 or t22, and t30), and , which is generated by subtracting from . DLMO was estimated by multiple regression analysis with the leave-one-out cross-validation (LOOCV) method using and , and . The intraclass correlation coefficient (ICC) between the estimated and measured DLMOs was used as the index of estimation accuracy. DLMOs estimated using multiple regression equations with and yielded significant ICCs for the measured DLMOs, with the largest ICC at t20 (ICC = 0.634). Additionally, the ICC between the estimated and measured DLMOs using the equation with was significant, with a larger ICC at t20 (ICC = 0.726) than that of the equation with and . Our results showed that DLMO could be estimated with a certain level of accuracy from salivary melatonin levels at three time points before and after sleep in children.
Supplementary Information:
The online version contains supplementary material available at 10.1007/s41105-023-00493-x.
