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High endogenous melatonin levels in critically ill children: a pilot study
Lucia Marseglia1, Salvatore Aversa, Ignazio Barberi
1Neonatal Intensive Care Unit, Department of Pediatrics, University of Messina, Messina, Italy.
Insights
Critically ill children show disrupted melatonin circadian rhythms and higher melatonin levels, potentially to combat oxidative stress. Light exposure further suppressed melatonin in these vulnerable pediatric patients.
Area of Science:
- Pediatric critical care medicine
- Endocrinology
- Circadian biology
Background:
- Melatonin secretion is crucial for regulating circadian rhythms.
- Data on melatonin levels and circadian rhythm in critically ill pediatric patients are scarce.
- Oxidative stress is elevated in critically ill children.
Purpose of the Study:
- To assess serum melatonin levels in critically ill pediatric patients.
- To investigate the impact of light exposure on melatonin's circadian rhythm in this population.
- To compare melatonin secretion patterns with healthy children.
Main Methods:
- Serum melatonin levels were measured in 16 mechanically ventilated pediatric intensive care unit patients.
- Patients were randomized into dark-exposed or light-exposed groups.
- Blood samples were collected at multiple time points over 24 hours.
Main Results:
- Critically ill children exhibited a severely disrupted melatonin circadian rhythm.
- Light exposure significantly lowered serum melatonin levels, even with an altered circadian cycle.
- Healthy children demonstrated higher peak melatonin levels compared to critically ill patients.
Conclusions:
- Elevated melatonin levels in critically ill children might be an adaptive response to high oxidative stress.
- The clinical significance and potential benefits of these altered melatonin levels in pediatric critical illness require further investigation.
- Disruption of the melatonin circadian rhythm is a notable finding in pediatric critical care.
Objective:
To evaluate the serum melatonin levels in critically ill pediatric patients and to test the effect of light on the melatonin's circadian rhythm. Data on melatonin secretion in critically ill pediatric subjects are lacking.
Study Design:
We investigated the serum melatonin levels of 16 sedated and mechanically ventilated patients in a pediatric intensive care unit. Children (mean age, 5.1 ± 3.1 years) were randomly assigned to a dark-exposed or to a light-exposed group to evaluate the effects of light on serum melatonin concentrations. Blood samples for serum melatonin analysis were collected at 10 p.m., 1 a.m., 3 a.m., 5 a.m., 8 a.m., and 12 p.m.
Results:
The melatonin circadian rhythm was severely disrupted in critically ill children; light exposure lowered serum melatonin even in a context of highly altered circadian cycle; melatonin peaks were greater for healthy age-matched children.
Conclusion:
The high melatonin levels in the critically ill children may be a response to counteract the elevated oxidative stress associated with serious diseases. Whether these elevated melatonin levels confer any beneficial effects in pediatric critically ill patients remains unknown.
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