Circadian phase in adults of contrasting ages

D. F. Kripke, S. D. Youngstedt, J. A. Elliott, A. Tuunainen, K. M. Rex, R. L. Hauger, M. R. Marler

Research output: Contribution to journalArticle

59 Scopus citations

Abstract

There is evidence that aging may impair phase-shifting responses to light synchronizers, which could lead to disturbed or malsynchronized circadian rhythms. To explore this hypothesis, 62 elder participants (age, 58 to 84 years) and 25 young adults (age, 19 to 40 years) were studied, first with baseline 1-wk wrist actigraphy at home and then by 72 h in-laboratory study using an ultra-short sleep-wake cycle. Subjects were awake for 60 minutes in 50 lux followed by 30 minutes of darkness for sleep. Saliva samples were collected for melatonin, and urine samples were collected for aMT6s (a urinary metabolite of melatonin) and free cortisol every 90 minutes. Oral temperatures were also measured every 90 minutes. The timing of the circadian rhythms was not significantly more variable among the elders. The times of lightsout and wake-up at home and urinary free cortisol occurred earlier among elders, but the acrophases (cosinor analysis-derived peak time) of the circadian rhythm of salivary melatonin, urinary aMT6s, and oral temperature were not significantly phase-advanced among elders. The estimated duration of melatonin secretion was 9.9 h among elders and 8.4 h among young adults (p < 0.025), though the estimated half-life of blood melatonin was shorter among elders (p < 0.025), and young adults had higher saliva melatonin and urinary aMT6s levels. In summary, there was no evidence for circadian desynchronization associated with aging, but there was evidence of some rearrangement of the internal phase-angles among the studied circadian rhythms.

Original languageEnglish (US)
Pages (from-to)695-709
Number of pages15
JournalChronobiology International
Volume22
Issue number4
DOIs
StatePublished - Oct 4 2005
Externally publishedYes

Keywords

  • Aging
  • Circadian Rhythm
  • Cortisol
  • Melatonin
  • Sleep
  • aMT6s

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Circadian phase in adults of contrasting ages'. Together they form a unique fingerprint.

  • Cite this

    Kripke, D. F., Youngstedt, S. D., Elliott, J. A., Tuunainen, A., Rex, K. M., Hauger, R. L., & Marler, M. R. (2005). Circadian phase in adults of contrasting ages. Chronobiology International, 22(4), 695-709. https://doi.org/10.1080/07420520500180439