title: Relationship between smoking and sleep apnea in clinic population.
abstract: OBJECTIVE
  To examine the relationship between smoking and sleep apnea.
  
  
  METHODS
  Cross-sectional case study
  
  
  METHODS
  University hospital sleep clinic
  
  
  METHODS
  We studied 3,509 patients.
  
  
  METHODS
  None
  
  
  RESULTS
  Smoking history (past, present, never-smoker, pack-years of smoking) and nocturnal polysomnography was obtained in all patients. Data analysis was performed as follows: Patients were divided into groups based on apnea seventy (to compare smoking), and on smoking seventy (to compare apnea hypopnea index - AHI). The relationship between smoking and apnea was examined using univariate, multivariate, and logistic regression analysis. We found that patients with AHI greater than 50 were heavier smokers than nonapneic controls (14+/-17 vs. 10+/-17 pack-years, respectively). Conversely, heavy smokers had higher AHI than non-smokers (26.3+/-28.3 vs. 19.7+/-23.9, respectively). There was no significant relationship between AHI and smoking in multiple regression analysis. Although logistic regression revealed that heavy smokers (>30 pack-yrs) had almost twice the risk of having AHI greater than 50 compared to nonsmokers, the odds ratio fell below one after adjusting for age, BMI, and gender.
  
  
  CONCLUSIONS
  In our patient population, smoking is not an independent risk factor for sleep apnea after adjusting for other confounding variables.
authors.affiliation: Department of Medicine, St. Michael's Hospital, University of Toronto, ON, Canada. victor.hoffstein@utoronto.ca
authors.forename: Victor
authors.initials: V
authors.lastname: Hoflstein
mesh_terms: D000886:Anthropometry; D015992:Body Mass Index; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D012907:Smoking / Q000453:epidemiology*