Abstract
Melatonin blanches the skin of frogs, whitens the fur of hamsters, and sometimes makes the gonads atrophy. It is remarkable that such a hormone would be put forward as a defense against ageing. We have been examining excretion of the urinary metabolite of melatonin, 6-sulphatoxymelatonin (6-SMT), in 150 postmenopausal women, in 72 volunteers over the age of 60 years who complained of insomnia or depression, and in 20 healthy younger adult controls, aged 18-40 years. The acrophase or fitted peak of 6-SMT excretion was computed as a marker of the timing of the circadian system. Total daily excretion of 6-SMT was not significantly related to total sleep time, wake-within-sleep or sleep complaints. Nevertheless, whereas the 20 controls displayed a normal range of 6-SMT acrophases from 01.32 to 05.44 h, 42% of the postmenopausal women and 48% of the symptomatic elders had acrophases outside this normal range. Those volunteers with more deviant acrophases displayed more disturbed sleep and more sleep complaints. These data suggest that melatonin is a useful marker of circadian rhythm phase disorders, but suggest a need for more caution in melatonin administration.
Original language | English (US) |
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Pages (from-to) | 81-87 |
Number of pages | 7 |
Journal | Annals of Medicine |
Volume | 30 |
Issue number | 1 |
DOIs | |
State | Published - 1998 |
Externally published | Yes |
Keywords
- Ageing
- Circadian rhythm
- Insomnia
- Melatonin
- Sleep
- Sulphatoxymelatonin
ASJC Scopus subject areas
- General Medicine