A preliminary study on the relationships between diurnal melatonin secretion profile and sleep variables in patients emergently admitted to the coronary care unit

Abstract

To clarify the significance of melatonin secretion under intensive care conditions, we investigated melatonin secretion profiles and sleep parameters of 23 patients just after admission to the coronary care unit (CCU) and 19 age-matched controls. Sleep parameters were evaluated by actigraphy, and melatonin secretion was assessed by measuring the urinary 6-sulphatoxy melatonin (6-SMT). 6-SMT secretion was lower and nocturnal sleep parameters were less satisfactory in the subjects than those in the controls, and there were positive correlations between these variables, particularly in the subject patients. The lowered melatonin secretion might be involved in the mechanism of insomnia in CCU patients.

• Cardiac diseases
• insomnia
• intensive care unit
• melatonin
• sleep disturbance

ACKNOWLEDGEMENTS

The authors are indebted to the medical editors from the Department of International Medical Communications of Tokyo Medical University for editing and reviewing the initial English manuscript.

DECLARATION OF INTEREST

This work was performed at Tokyo Medical University, Tokyo, Japan. All of the authors have no conflicts of interest to disclose. Financial support for this study was provided by Health Science Grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan (23591731).