title: Sleep continuity is positively correlated with sleep duration in laboratory nighttime sleep recordings.
abstract: Sleep duration varies widely across individuals and appears to be trait-like. Differences in the stability of underlying sleep processes may underlie this phenomenon. To investigate underlying mechanisms, we examined the relationship between sleep duration and sleep continuity in baseline polysomnography (PSG) recordings from three independently collected datasets: 1) 134 healthy controls (ages 37 ± 13 years) from the São Paulo Epidemiologic Sleep Study, who spent one night in a sleep laboratory, 2) 21 obstructive sleep apnea (OSA) patients who were treated with continuous positive airway pressure for at least 2 months (45 ± 12 years, respiratory disturbance index <15), who spent one night in a sleep laboratory with previous experience of multiple PSG studies, and 3) 62 healthy controls (28 ± 6 years) who, as part of larger experiments, spent 2 consecutive nights in a sleep laboratory. For each dataset, we used total sleep time (TST) to separate subjects into those with shorter sleep (S-TST) and those with longer sleep (L-TST). In all three datasets, survival curves of continuous sleep segments showed greater sleep continuity in L-TST than in S-TST. Correlation analyses with TST as a continuous variable corroborated the results; and the results also held true after controlling for age. There were no significant differences in baseline waking performance and sleepiness between S-TST and L-TST. In conclusion, in both healthy controls and treated OSA patients, sleep continuity was positively correlated with sleep duration. These findings suggest that S-TST may differ from L-TST in processes underlying sleep continuity, shedding new light on mechanisms underlying individual differences in sleep duration.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, New York, New York, United States of America.|Pain & Fatigue Study Center, Beth Israel Medical Center and Albert Einstein College of Medicine, New York, New York, United States of America.|Graduate School of Education, The University of Tokyo, Tokyo, Japan.
authors.forename: Akifumi
authors.identifier: http://orcid.org/0000-0002-9324-536X
authors.initials: A
authors.lastname: Kishi
authors.affiliation: Sleep and Performance Research Center, Washington State University, Spokane, Washington, United States of America.
authors.forename: Hans P A
authors.initials: HP
authors.lastname: Van Dongen
authors.affiliation: Pain & Fatigue Study Center, Beth Israel Medical Center and Albert Einstein College of Medicine, New York, New York, United States of America.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Natelson
authors.affiliation: Sleep and Performance Research Center, Washington State University, Spokane, Washington, United States of America.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Bender
authors.affiliation: Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Luciana O
authors.initials: LO
authors.lastname: Palombini
authors.affiliation: Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Lia
authors.initials: L
authors.lastname: Bittencourt
authors.affiliation: Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, New York, New York, United States of America.
authors.forename: Indu
authors.initials: I
authors.lastname: Ayappa
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, New York, New York, United States of America.
authors.forename: David M
authors.initials: DM
authors.lastname: Rapoport
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure; D066264:Datasets as Topic; D005221:Fatigue; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000628:therapy; D016019:Survival Analysis; D013997:Time Factors; D014851:Wakefulness; D055815:Young Adult