title: Sleep is more sensitive to high doses of caffeine in the middle years of life.
abstract: During the middle years of life, sleep becomes more fragile and its sensitivity to psychostimulants may increase. This study evaluated the effects of 200 mg and 400 mg of caffeine on sleep in young and middle-aged adults. The sleep of 22 young (23.5 ± 1.9 years) and 24 middle-aged (51.7 ± 11.5 years) adults was recorded using polysomnography in two conditions (placebo and caffeine) in a double-blind cross-over design. Compared to placebo, caffeine increased sleep latency, shortened total sleep duration and reduced sleep efficiency. At the higher dose, these effects were more pronounced in middle-aged than in young adults. Furthermore, the higher dose of caffeine increased absolute stage 1 sleep in young adults, whereas it decreased absolute stage 2 sleep in middle-aged adults. Caffeine also induced dose-dependent increases in relative stage 1 sleep and reductions in absolute and relative slow wave sleep and absolute rapid eye movement sleep in both age groups. There was no dose- or age-related modulation of the effects of caffeine on quantified electroencephalographic measures. These results indicate that, compared to young adults, middle-aged adults are generally more sensitive to the effects of a high dose of caffeine on sleep quantity and quality.
authors.affiliation: Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada.
authors.forename: Rébecca
authors.initials: R
authors.lastname: Robillard
authors.affiliation: Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada.
authors.forename: Maude
authors.initials: M
authors.lastname: Bouchard
authors.affiliation: Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada.
authors.forename: Annick
authors.initials: A
authors.lastname: Cartier
authors.affiliation: Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada.
authors.forename: Laurence
authors.initials: L
authors.lastname: Nicolau
authors.affiliation: Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada Institut Universitaire de Gériatrie de Montréal, Université de Montréal, Montréal, QC, Canada Département de Psychologie, Université de Montréal, Montréal, QC, Canada julie.carrier.1@umontreal.ca.
authors.forename: Julie
authors.initials: J
authors.lastname: Carrier
mesh_terms: D000328:Adult; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012895:Sleep, REM / Q000187:drug effects*; D014851:Wakefulness / Q000187:drug effects; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine
keywords: Caffeine; aging; dose; polysomnography; sleep