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Titolo:
Circadian phase resetting in older people by ocular bright light exposure
Autore:
Klerman, EB; Duffy, JF; Dijk, DJ; Czeisler, CA;
Indirizzi:
Harvard Univ, Sch Med, Dept Med,Div Endocrinol Hypertens, Circadian Neuroendocrine & Sleep Disorders Sect, Boston, MA 02115 USA Harvard Univ Boston MA USA 02115 eep Disorders Sect, Boston, MA 02115 USA Brigham & Womens Hosp, Boston, MA 02115 USA Brigham & Womens Hosp Boston MA USA 02115 mens Hosp, Boston, MA 02115 USA
Titolo Testata:
JOURNAL OF INVESTIGATIVE MEDICINE
fascicolo: 1, volume: 49, anno: 2001,
pagine: 30 - 40
SICI:
1081-5589(200101)49:1<30:CPRIOP>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAT SUPRACHIASMATIC NUCLEUS; AGE-RELATED-CHANGES; TEMPERATURE RHYTHMS; GLUCOSE-UTILIZATION; SLEEP; PACEMAKER; AMPLITUDE; YOUNG; ENTRAINMENT; MELATONIN;
Keywords:
circadian rhythms; body temperature; phototherapy; phase shifts; phase response curve; aging;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
56
Recensione:
Indirizzi per estratti:
Indirizzo: Klerman, EB Harvard Univ, Sch Med, Dept Med,Div Endocrinol Hypertens, Circadian Neuroendocrine & Sleep Disorders Sect, 221 Longwood Ave, Boston, MA 02115 USA Harvard Univ 221 Longwood Ave Boston MA USA 02115 MA 02115 USA
Citazione:
E.B. Klerman et al., "Circadian phase resetting in older people by ocular bright light exposure", J INVES MED, 49(1), 2001, pp. 30-40

Abstract

Background: Aging is associated with frequent complaints about earlier bedtimes and waketimes, These changes in sleep timing are associated with an earlier timing of multiple endogenous rhythms, including core body temperature (CBT) and plasma melatonin, driven by the circadian pacemaker. One possible cause of the age-related shift of endogenous circadian rhythms and the timing of sleep relative to clack time is a change in the phase-shifting capacity of the circadian pacemaker in response to the environmental light-dark cycle, the principal synchronizer of the human circadian system. Methods: We studied the response of the circadian system of 24 older men and women and 23 young men to scheduled exposure to ocular bright light stimuli. Light stimuli were 5 hours in duration, administered for 3 consecutivedays at an illuminance of similar to 10,000 lux. Light stimuli were scheduled 1.5 or 3.5 hours after the CBT nadir to induce shifts of endogenous circadian pacemaker to an earlier hour (phase advances) or were scheduled 1.5 hours before the CBT nadir to induce shifts to a later hour (phase delays). The rhythms of CBT and plasma melatonin assessed under constant conditionsserved as markers of circadian phase. Results: Bright light stimuli elicited robust responses of the circadian timing system in older people; both phase advances and phase delays were induced. The magnitude of the phase delays did not differ significantly between older and younger individuals, but the phase advances were significantly attenuated in older people. Conclusions: The attenuated response to light stimuli that induce phase advances does not explain the advanced phase of the circadian pacemaker in older people. The maintained responsiveness of tbe circadian pacemaker to light implies that scheduled bright light exposure can be used to treat circadian phase disturbances in older people.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 08/04/20 alle ore 22:51:06