Skip to main content
Total Daily Production and Periodicity of Melatonin Metabolite in Critically Ill Children
Pediatric Critical Care Medicine
  • Jennifer R Foster, Western University
  • Janice A. Tijssen, Western University
  • Michael R. Miller, Western University
  • Jamie A. Seabrook, Brescia University
  • Douglas Fraser, Western University
Document Type
Publication Date
URL with Digital Object Identifier

OBJECTIVES: To determine whether total daily 6-sulfatoxymelatonin excretion and diurnal variation of melatonin secretion was maintained during the early phase of PICU admission through examination of the melatonin urinary metabolite, 6-sulfatoxymelatonin.

DESIGN: Exploratory prospective, observational study.

SETTING: Twelve-bed medical-surgical PICU of a Children's Hospital.

PATIENTS: Fifty children 3 months to 18 years old enrolled within 24 hours of PICU admission with access for urinary sampling.


MEASUREMENTS AND MAIN RESULTS: Urine samples were collected at 4-hour intervals for 24 hours and stored at -80C. 6-sulfatoxymelatonin was determined in duplicate by direct enzyme-linked immunosorbent assay. Patients were heterogeneous for diagnosis, had a mean age of 8.1 years (SD = 6.1 yr), and median (interquartile range) Pediatric Risk of Mortality III of 10 (4-13). Mean (SD) total daily 6-sulfatoxymelatonin production was 30.0 µg (25.6 µg) for the first 24 hours, which did not differ significantly from the means on days 2 (p = 0.56) or 3 (p = 0.29), and was similar to literature controls. Mean 6-sulfatoxymelatonin production for the population fit a periodic function well, with a reliable amplitude of 326 ng/hr and peak excretion from 04:00 to 08:00 (F = 4.4, p = 0.01), even when 6-sulfatoxymelatonin was corrected for body weight (F = 3.4, p = 0.03) and when sedation was included in the model (F = 3.95, p = 0.004). There was no significant correlation between lighting and 6-sulfatoxymelatonin excretion at any time period (R values: 0.11-0.25, p = 0.10-0.94). Mean 6-sulfatoxymelatonin excretion did not fit the model for a periodic function well for the subpopulations studied (sepsis [n = 18, F = 1.1, p = 0.32], respiratory failure requiring deep sedation [n = 10, F = 0.4, p = 0.66], and neurologic injury [n = 7, F = 0.6, p = 0.55]).

CONCLUSIONS: Total daily and diurnal variation of 6-sulfatoxymelatonin excretion is heterogeneously maintained early in pediatric critical illness. However, this may not hold true for specific diagnostic categories.

Citation Information
Jennifer R Foster, Janice A. Tijssen, Michael R. Miller, Jamie A. Seabrook, et al.. "Total Daily Production and Periodicity of Melatonin Metabolite in Critically Ill Children" Pediatric Critical Care Medicine Vol. 21 Iss. 12 (2020) p. e1061 - e1068
Available at: