Circadian Phase in Adults of Contrasting Ages
| Autor: | Jeffrey A. Elliott, Shawn D. Youngstedt, Katharine M. Rex, Arja Tuunainen, Matthew Marler, Daniel F. Kripke, Richard L. Hauger |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Adult
Aging medicine.medical_specialty Saliva Hydrocortisone Physiology Urinary system Urine Biology Body Temperature Melatonin 03 medical and health sciences 0302 clinical medicine Physiology (medical) Internal medicine medicine Humans Circadian rhythm Young adult Aged 030304 developmental biology 0303 health sciences Actigraphy Middle Aged Circadian Rhythm Endocrinology Darkness 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Chronobiology International. 22:695-709 |
| ISSN: | 1525-6073 0742-0528 |
| DOI: | 10.1080/07420520500180439 |
| Popis: | 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 lights-out 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|