title: A nationwide, cross-sectional survey on unusual sleep postures and sleep-disordered breathing-related symptoms in people with Down syndrome.
abstract: People with Down syndrome (DS) often have sleep-disordered breathing (SDB). Unusual sleep postures, such as leaning forward and sitting, are observed in people with DS. This study aimed to clarify the prevalence of unusual sleep postures and their relationships with SDB-related symptoms (SDB-RSs), such as snoring, witnessed apnoea, nocturnal awakening and excessive daytime sleepiness.
  
  
  
  A questionnaire, including demographic characteristics and the presence of unusual sleep postures, as well as SDB-RSs, was completed by 1149 parents of people with DS from Japan.
  
  
  
  Unusual sleep postures were recorded in 483 (42.0%) people with DS. These participants were significantly younger and had a history of low muscle tone more frequently than people without unusual sleep postures. In all ages, the leaning forward posture was more frequent than sitting. People with DS with unusual sleep postures suffered from SDB-RSs. Those who slept in the sitting posture had more frequent SDB-RSs than did those who slept with the leaning forward posture. Snoring, witnessed apnoea and nocturnal awakening were observed in 73.6, 27.2 and 58.2% of participants, respectively. Snoring increased with aging. Witnessed apnoea was more common in males and in those with hypothyroidism than in females and in those without hypothyroidism.
  
  
  
  Our study shows that there is a close relationship between unusual sleep postures and SDB-RSs. We recommend that all people with DS with unusual sleep postures should be checked for the presence of SDB.
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kuroda
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sawatari
authors.affiliation: Sleep Apnea Center, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ando
authors.affiliation: Faculty of Health Sciences, Ube Frontier University, Ube, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohkusa
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Rahmawati
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Ono
authors.affiliation: Kirameki Projects Career Support Center, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nishizaka
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Hashiguchi
authors.affiliation: Department of Medicine, Kyushu University School of Medicine, Fukuoka, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Matsuoka
authors.affiliation: Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Chishaki
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003430:Cross-Sectional Studies; D006970:Disorders of Excessive Somnolence / Q000503:physiopathology*; D004314:Down Syndrome / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology*; D012913:Snoring / Q000503:physiopathology*; D055815:Young Adult
keywords: Down syndrome; sleep apnoea; sleep posture; sleep-disordered breathing