title: Pathogenetic role of increased nasal resistance in obese patients with obstructive sleep apnea syndrome.
abstract: BACKGROUND
  The role of increased nasal resistance in obstructive sleep apnea syndrome (OSAS) remains controversial. The aim of this study was to examine the pathogenetic role of nasal obstruction in obese patients with OSAS.
  
  
  METHODS
  Patients with OSAS (n = 125) at a university hospital were divided into three groups according to body mass index (BMI): nonobese (BMI < 25 kg/m(2)), mildly obese (25 kg/m(2) < or = BMI < 30 kg/m(2)), and obese (BMI > or = 30 kg/m(2)). The subjects underwent nasopharyngoscopy, measurement of nasal resistance, and polysomnography.
  
  
  RESULTS
  We studied 42 nonobese, 47 mildly obese, and 36 obese patients with OSAS. Among the obese, but not the nonobese and mildly obese patients, we found significant correlations between the oxygen desaturation index (ODI) and bilateral nasal resistance (BNR; r = 0.412; p = 0.013), between the ODI and unilateral higher nasal resistance (UHNR; r = 0.413; p = 0.012), and between the apnea index and UHNR (r = 0.334; p = 0.046). Multiple regression analysis incorporating all patients showed that BMI (p < 0.001) and BNR (p = 0.033) were independently related to the ODI.
  
  
  CONCLUSIONS
  In obese patients with OSAS, increased nasal resistance could play an important pathogenetic role in hypoxemic apnea.
authors.affiliation: Department of Otorhinolaryngology, Graduate School of Medicine, Nagoya University, Nagoya, Aichi, Japan.
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Tagaya
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nakata
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yasuma
authors.forename: Akiko
authors.initials: A
authors.lastname: Noda
authors.forename: Mami
authors.initials: M
authors.lastname: Morinaga
authors.forename: Hidehito
authors.initials: H
authors.lastname: Yagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Sugiura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Teranishi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000403:Airway Resistance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015508:Nasal Obstruction / Q000150:complications*; D009765:Obesity / Q000150:complications*; D017286:Polysomnography; D025363:Rhinomanometry; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011795:Surveys and Questionnaires