title: Association between positional changes in laboratory values and severity in subjects with obstructive sleep apnea syndrome.
abstract: BACKGROUND
  The aim of the study was to investigate the association between the difference (defined as the remainder, Rm) in laboratory values determined in the upright and supine positions and the severity of obstructive sleep apnea syndrome (OSAS).
  
  
  METHODS
  Thirty-three Japanese male subjects with OSAS [apnea/hypopnea index (AHI: the number of apneas and hypopneas per hour) > or =5] underwent cephalometric analysis and measurements of nasal resistance in the upright and supine positions. Several parameters in a dental model and physical features were also analyzed.
  
  
  RESULTS
  Significant associations of the logarithmic AHI, with neck depth, Rm for the facial axis, and the minimum airway behind the tongue in the supine position were found in multiple linear regression analysis.
  
  
  CONCLUSIONS
  Our results suggest that neck depth, Rm for the facial axis and the minimum airway behind the tongue in the supine position may be determinants of the severity of OSAS.
authors.affiliation: General Dentistry, Department of Comprehensive Oral Health Care, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Japan. yellowcube.gend@tmd.ac.jp
authors.forename: Risa
authors.initials: R
authors.lastname: Tamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Ono
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Keiji
authors.initials: K
authors.lastname: Moriyama
authors.forename: Kouji
authors.initials: K
authors.lastname: Araki
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002508:Cephalometry; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015508:Nasal Obstruction; D009333:Neck / Q000473:pathology; D056888:Patient Positioning; D010614:Pharynx / Q000473:pathology; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000473:pathology; D018709:Statistics, Nonparametric; D016683:Supine Position