title: Family studies in patients with the sleep apnea-hypopnea syndrome.
abstract: OBJECTIVE
  To determine whether familial factors affect development of the sleep apnea-hypopnea syndrome and upper airway caliber.
  
  
  METHODS
  A case-control study.
  
  
  METHODS
  Tertiary, referral clinical sleep laboratory.
  
  
  METHODS
  51 first-degree relatives of patients with the sleep apnea-hypopnea syndrome and 51 controls matched for age, sex, height, and weight who were drawn at random from a family practice register. To avoid studying the familial nature of obesity, only relatives of index patients with body mass indices less than 30.0 kg/m2 were recruited.
  
  
  METHODS
  Assessment of sleep-related symptoms; breathing, sleep, and oxygenation patterns on overnight polysomnograms; upper airway dimensions by acoustic reflection; and facial structure by lateral cephalometry.
  
  
  RESULTS
  More relatives of patients with the sleep apnea-hypopnea syndrome reported snoring (24 relatives compared with 7 controls; P < 0.001) and daytime sleepiness (28 relatives compared with 16 controls; P = 0.01). Relatives had more apneas and hypopneas per hour (median of 13/h [95% CI, 3 to 82/h] for relatives compared with median of 4/h [CI, 0 to 53/h] for controls; P < 0.001), more arousals from sleep (30/h [CI, 11 to 87/h] for relatives compared with 17/h [CI, 4 to 59/h] for controls; P < 0.001), poorer sleep quality, and more oxygen desaturations. Relatives also had narrower upper airways with retroposed maxillae and mandibles and longer soft palates with wider uvulae.
  
  
  CONCLUSIONS
  The sleep apnea-hypopnea syndrome has a strong familial component. The familial tendency may be caused by differences in facial structure.
authors: University of Edinburgh, United Kingdom.
authors: R
authors: R
authors: Mathur
authors: N J
authors: NJ
authors: Douglas
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000150:complications; D016022:Case-Control Studies; D002508:Cephalometry; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology; D008437:Maxilla / Q000033:anatomy & histology; D008875:Middle Aged; D012022:Reflex, Acoustic; D012890:Sleep / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D012913:Snoring / Q000150:complications; D011795:Surveys and Questionnaires