Melatonin: marvel or marker?

Ann Med. 1998 Feb;30(1):81-7. doi: 10.3109/07853899808999388.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / physiology
  • Case-Control Studies
  • Circadian Rhythm / physiology*
  • Depression / physiopathology
  • Depression / urine
  • Female
  • Humans
  • Male
  • Melatonin* / analogs & derivatives
  • Melatonin* / metabolism
  • Melatonin* / physiology
  • Melatonin* / therapeutic use
  • Melatonin* / urine
  • Middle Aged
  • Postmenopause / urine
  • Sleep Initiation and Maintenance Disorders / physiopathology
  • Sleep Initiation and Maintenance Disorders / urine


  • 6-sulfatoxymelatonin
  • Melatonin