title: Smoking and sleep disorders in Chinese adolescents.
abstract: OBJECTIVE
  To investigate the association between adolescent smoking and sleep disorders.
  
  
  METHODS
  In the Hong Kong student obesity surveillance project, 29,397 Chinese students, aged 12-18 years, completed a health survey. Insomnia was defined as having any of the following three symptoms: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA). The presence of snoring and difficulty breathing during sleep (DBS) was also reported. Logistic regression yielded adjusted odds ratios (ORs) for each sleep disorder by smoking status.
  
  
  RESULTS
  Compared with never smokers, the ORs (95% CI) of insomnia were 1.39 (1.25-1.54) for experimenters (smoked once or a few times) and 0.91 (0.83-1.00) for current smokers. The corresponding ORs were 1.42 (1.16-1.74) and 3.58 (3.15-4.06) for snoring (P for trend<0.001) and 1.40 (1.10-1.79) and 3.39 (2.97-4.03) for DBS (P for trend<0.001). Current smokers compared with never smokers were less likely to report DIS (OR=0.43, 95% CI=0.38-0.50, P<0.001) and EMA (OR=0.83, 95% CI=0.73-0.94, P=0.003), but more likely to report DMS (OR=1.45, 95% CI=1.28-1.63, P<0.001).
  
  
  CONCLUSIONS
  In terms of dosage, adolescent smoking was associated with snoring and DBS, with increasing ORs from never smokers to experimental and current smokers. Current smoking was associated positively with DMS, but negatively with DIS and EMA.
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong.
authors.forename: Kwok-Kei
authors.initials: KK
authors.lastname: Mak
authors.forename: Sai-Yin
authors.initials: SY
authors.lastname: Ho
authors.forename: G Neil
authors.initials: GN
authors.lastname: Thomas
authors.forename: Wing-Sze
authors.initials: WS
authors.lastname: Lo
authors.forename: Daniel Ka-Leung
authors.initials: DK
authors.lastname: Cheuk
authors.forename: Yuen-Kwan
authors.initials: YK
authors.lastname: Lai
authors.forename: Tai-Hing
authors.initials: TH
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006306:Health Surveys; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D012891:Sleep Apnea Syndromes / Q000453:epidemiology / Q000209:etiology; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology / Q000209:etiology; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000209:etiology*; D012907:Smoking / Q000009:adverse effects*; D012913:Snoring / Q000453:epidemiology / Q000209:etiology