title: Altered Sleep Stage Transitions of REM Sleep: A Novel and Stable Biomarker of Narcolepsy.
abstract: OBJECTIVE
  To determine the diagnostic values, longitudinal stability, and HLA association of the sleep stage transitions in narcolepsy.
  
  
  METHODS
  To compare the baseline differences in the sleep stage transition to REM sleep among 35 patients with type 1 narcolepsy, 39 patients with type 2 narcolepsy, 26 unaffected relatives, and 159 non-narcoleptic sleep patient controls, followed by a reassessment at a mean duration of 37.4 months.
  
  
  RESULTS
  The highest prevalence of altered transition from stage non-N2/N3 to stage R in multiple sleep latency test (MSLT) and nocturnal polysomnography (NPSG) was found in patients with type 1 narcolepsy (92.0% and 57.1%), followed by patients with type 2 narcolepsy (69.4% and 12.8%), unaffected relatives (46.2% and 0%), and controls (39.3% and 1.3%). Individual sleep variables had varied sensitivity and specificity in diagnosing narcolepsy. By incorporating a combination of sleep variables, the decision tree analysis improved the sensitivity to 94.3% and 82.1% and enhanced specificity to 82.4% and 83% for the diagnosis of type 1 and type 2 narcolepsy, respectively. There was a significant association of DBQ1*0602 with the altered sleep stage transition (OR = 16.0, 95% CI: 1.7-149.8, p = 0.015). The persistence of the altered sleep stage transition in both MSLT and NPSG was high for both type 1 (90.5% and 64.7%) and type 2 narcolepsy (92.3% and 100%), respectively.
  
  
  CONCLUSIONS
  Altered sleep stage transition is a significant and stable marker of narcolepsy, which suggests a vulnerable wake-sleep dysregulation trait in narcolepsy. Altered sleep stage transition has a significant diagnostic value in the differential diagnosis of hypersomnias, especially when combined with other diagnostic sleep variables in decision tree analysis.
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Jihui
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Venny
authors.initials: V
authors.lastname: Lam
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Crover Kwok Wah
authors.initials: CK
authors.lastname: Ho
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.|Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Shirley Xin
authors.initials: SX
authors.lastname: Li
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Siu Ping
authors.initials: SP
authors.lastname: Lam
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Mandy Wai Man
authors.initials: MW
authors.lastname: Yu
authors.affiliation: Sleep Medicine Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Yun-Kwok
authors.initials: YK
authors.lastname: Wing
mesh_terms: D000328:Adult; D015415:Biomarkers; D005260:Female; D006801:Humans; D008297:Male; D009290:Narcolepsy / Q000175:diagnosis* / Q000503:physiopathology*; D017286:Polysomnography; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: biomarker; hypersomnia; multiple sleep latency test; narcolepsy; sleep onset REM sleep period; sleep stage transitions