title: Familial risk of sleep-disordered breathing.
abstract: OBJECTIVE
  To estimate the incidence of hospitalization for paediatric obstructive sleep apnoea syndrome (OSAS) or sleep-disordered breathing (SDB) caused by adenotonsillar or tonsillar hypertrophy without infection in children with a parent affected by OSAS.
  
  
  METHODS
  Using the MigMed database at Lund University, hospital data on all children aged 0-18 years in Sweden between 1997 and 2007 (total of 3 million individuals) were used to identify all first hospital admissions for OSAS or either adenotonsillar or tonsillar hypertrophy. Next, individuals were categorized as either having or not having a parent affected by OSAS. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were estimated for boys and girls with a parent affected by OSAS. Children with OSAS or adenotonsillar or tonsillar hypertrophy without a parent affected by OSAS acted as the reference group (SIR=1).
  
  
  RESULTS
  After accounting for socio-economic status, age, and geographic region, the SIRs of OSAS in boys and girls with a parent affected by OSAS were 3.09 (95% CI 1.83-4.90) and 4.46 (95% CI 2.68-6.98), respectively. The SIRs of adenotonsillar or tonsillar hypertrophy in boys and girls with a parent affected by OSAS were 1.82 (95% CI 1.54-2.14) and 1.56 (95% CI 1.30-1.87), respectively.
  
  
  CONCLUSIONS
  This study indicates familial clustering of sleep-disordered breathing, which is important information for clinicians.
authors.affiliation: Department of Otorhinolaryngology, Karolinska Institutet, Stockholm, Sweden. karin.lundkvist@karolinska.se
authors.forename: Karin
authors.initials: K
authors.lastname: Lundkvist
authors.forename: Kristina
authors.initials: K
authors.lastname: Sundquist
authors.forename: Xinjun
authors.initials: X
authors.lastname: Li
authors.forename: Danielle
authors.initials: D
authors.lastname: Friberg
mesh_terms: D000234:Adenoids / Q000473:pathology; D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual / Q000706:statistics & numerical data; D005192:Family Health; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006984:Hypertrophy; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D014066:Palatine Tonsil / Q000473:pathology; D012307:Risk Factors; D017678:Sex Distribution; D012891:Sleep Apnea Syndromes / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology; D013548:Sweden / Q000453:epidemiology