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Subjective alertness rhythms in elderly peopleThe aim of this study was to evaluate age-related changes in the circadian rhythm of subjective alertness and to explore the circadian mechanisms underlying such changes. Using a visual analogue scale (VAS) instrument, 25 older men and women (71 y and older; 15 female, 10 male) rated their subjective alertness about 7 times per day during 5 baseline days of temporal isolation during which habitual bedtimes and waketimes were enforced. Comparisons were made with 13 middle-aged men (37-52 y) experiencing the same protocol. Advancing age (particularly in the men) resulted in less rhythmic alertness patterns, as indicated by lower amplitudes and less reliability of fitted 24-h sinusoids. This appeared in spite of the absence of any reliable age-related diminution in circadian temperature rhythm amplitude, thus suggesting the effect was not due to SCN weakness per se, but to weakened transduction of SCN output. In a further experiment, involving 36 h of constant wakeful bedrest, differences in the amplitude of the alertness rhythm were observed between 9 older men (79 y+), 7 older women (79 y+), and 17 young controls (9 males, 8 females, 19-28 y) suggesting that with advancing age (particularly in men) there is less rhythmic input into subjective alertness from the endogenous circadian pacemaker. These results may explain some of the nocturnal insomnia and daytime hypersomnia that afflict many elderly people.
Document ID
20040173154
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Monk, T. H.
(University of Pittsburgh Medical Center PA 15213, United States)
Buysse, D. J.
Reynolds, C. F. 3rd
Kupfer, D. J.
Houck, P. R.
Date Acquired
August 22, 2013
Publication Date
September 1, 1996
Publication Information
Publication: Journal of biological rhythms
Volume: 11
Issue: 3
ISSN: 0748-7304
Subject Category
Behavioral Sciences
Funding Number(s)
CONTRACT_GRANT: MH01235
CONTRACT_GRANT: AG06836
CONTRACT_GRANT: MH00295
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Regulatory Physiology
Non-NASA Center
Randomized Controlled Trial
Clinical Trial

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