title: Is obstructive sleep apnea syndrome in children season dependent?
abstract: BACKGROUND
  The most common cause of obstructive sleep apnea (OSA) in children is an enlargement of tonsils and/or adenoids. Previous studies have shown that the size of adenoids and tonsils is influenced by upper respiratory tract infections and exposure to allergens. The rate of exposure to bacteria, viruses, and allergens fluctuates from season to season. Therefore, we hypothesized that the rate of polysomnograms positive for OSA may vary according to season.
  
  
  OBJECTIVE
  The objective of this study is to determine whether the prevalence of OSA in children, as determined by polysomnography, is affected by the season during which the study was performed.
  
  
  METHODS
  We retrospectively reviewed polysomnography tests of 296 children, ages 0-12 years, referred for suspected OSA. We compared the Obstructive Apnea Hypopnea Index (OAHI) between the seasons and the rates of abnormal tests in each season according to the degree of severity.
  
  
  RESULTS
  The mean OAHI did not significantly differ among the seasons (winter, 3.0 ± 5.0; spring, 3.0 ± 4.9; summer, 4.0 ± 6.3; fall, 3.4 ± 5.7, p = 0.183). When dividing the OAHI by levels of severity, no seasonality was found in moderate (winter, 13.8 %; spring, 6.7 %; summer, 11.7 %; fall, 14.1 %, p = NS) and severe OSA (winter, 8.8 %; spring, 11.2 %; summer, 10 %; fall, 7.8 %, p = NS). There was a small increase in the frequency of mild OSA diagnoses in the summer compared to the other seasons.
  
  
  CONCLUSIONS
  In this study, season does not appear to affect the rate of diagnosis of significant OSA in children. Re-evaluation during a different season is unlikely to provide different results and may postpone surgery unnecessarily.
authors.affiliation: Pediatric Pulmonary Unit, Shaare Zedek Medical Center, School of Medicine, affiliated with The Hebrew University school of medicine, Jerusalem, Israel.
authors.forename: Zev
authors.initials: Z
authors.lastname: Frimer
authors.affiliation: Pediatric Pulmonary Unit, Shaare Zedek Medical Center, School of Medicine, affiliated with The Hebrew University school of medicine, Jerusalem, Israel.
authors.forename: Shmuel
authors.initials: S
authors.lastname: Goldberg
authors.affiliation: Pediatric Pulmonary Unit, Shaare Zedek Medical Center, School of Medicine, affiliated with The Hebrew University school of medicine, Jerusalem, Israel.
authors.forename: Leon
authors.initials: L
authors.lastname: Joseph
authors.affiliation: Neonatal Department, Shaare Zedek Medical Center, affiliated with The Hebrew University school of medicine, POB 3235, Jerusalem, 91031, Israel.
authors.forename: Francis B
authors.initials: FB
authors.lastname: Mimouni
authors.affiliation: Pediatric Pulmonary Unit, Shaare Zedek Medical Center, School of Medicine, affiliated with The Hebrew University school of medicine, Jerusalem, Israel. picard@szmc.org.il.
authors.forename: Elie
authors.initials: E
authors.lastname: Picard
mesh_terms: D000234:Adenoids / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007223:Infant; D007231:Infant, Newborn; D007557:Israel; D008297:Male; D014066:Palatine Tonsil / Q000473:pathology*; D017286:Polysomnography; D012141:Respiratory Tract Infections / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012621:Seasons; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology
keywords: Children; Obstructive sleep apnea; Polysomnography; Season