Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Am J Physiol Endocrinol Metab. 2002 Feb;282(2):E297-303.

Peak of circadian melatonin rhythm occurs later within the sleep of older subjects.

Author information

  • 1Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. jduffy@hms.harvard.edu

Abstract

We investigated the relationship between sleep timing and the timing of the circadian rhythm of plasma melatonin secretion in a group of healthy young and older subjects without sleep complaints. The timing of sleep and the phase of the circadian melatonin rhythm were earlier in the older subjects. The relationship between the plasma melatonin rhythm and the timing of sleep was such that the older subjects were sleeping and waking earlier relative to their nightly melatonin secretory episode. Consequently, the older subjects were waking at a time when they had higher relative melatonin levels, in contrast with younger subjects, whose melatonin levels were relatively lower by wake time. Our findings indicate that aging is associated not only with an advance of sleep timing and the timing of circadian rhythms but also with a change in the internal phase relationship between the sleep-wake cycle and the output of the circadian pacemaker. In healthy older subjects, the relative timing of the melatonin rhythm with respect to sleep may not play a causal role in sleep disruption.

PMID:
11788360
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk