title: [Pharyngeal size and collapsibility in patients with obstructive sleep apnea hypopnea syndrome].
abstract: OBJECTIVE
  To study the pharyngeal cross-sectional area and collapsibility among the patients with obstructive sleep apnea hypopnea syndrome (OSAHS), simple snorers, and normal persons.
  
  
  METHODS
  171 patients with OSAHS, 44 with mild, 51 with moderate, and 56 with severe OSAHS, 47 simple snorers, and 47 healthy subjects underwent upper airway cross-sectional area measurement using acoustic pharyngometer at the conditions of functional residual capacity (FRC) and residual volume (RV) in the upright sitting position.
  
  
  RESULTS
  When the lung volume decreased from the condition of FRC to the condition of RV the pharyngeal cross-sectional area decreased from 2.63 cm(2) +/- 0.42 cm(2) to 1.96 cm(2) +/- 0.35 cm(2) for the simple snorers, 2.70 cm(2) +/- 0.44 cm(2) to 1.78 cm(2) +/- 0.39 cm(2) for the mild OSAHS patients, from 2.62 cm(2) +/- 0.52 cm(2) to 1.79 cm(2) +/- 0.37 cm(2) for the moderate OSAHS patients, and from 2.57 cm(2) +/- 0.46 cm(2) to 1.75 cm(2) +/- 0.40 cm(2) for the severe OSAHS patients, all with higher decrease rates (33.93% +/- 11.81%, 31.13% +/- 10.76%, and 31.31% +/- 13.44%) than that of the normal persons (25.07% +/- 10.39%), smaller than that for the normal persons (21.11% +/- 8.19%, from 3.05 cm(2) +/- 0.6 cm(2) to 2.38 cm(2) +/- 0. 47 cm(2), all P < 0.05). The change ratios of the 3 OSAHS groups were significantly higher than that of the simple snorer group (all P < 0.01). This indicated that the pharynges of OSAHS patients were more collapsible.
  
  
  CONCLUSIONS
  Snorers with or without apnea have smaller pharyngeal cross-sectional area than nonsnorers. The collapsibility of the upper airway is greater in both OSHAS patients and simple snorers than in healthy subjects.
authors.affiliation: Institute of Respiratory Medicine, Beijing Chaoyang Hospital, Capital University of Medical Sciences, Beijing 100020, China.
authors.forename: Yan-xia
authors.initials: YX
authors.lastname: Yu
authors.forename: Xi-heng
authors.initials: XH
authors.lastname: Guo
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000473:pathology / Q000503:physiopathology*; D017286:Polysomnography; D023842:Rhinometry, Acoustic; D020181:Sleep Apnea, Obstructive / Q000473:pathology / Q000503:physiopathology*; D014109:Total Lung Capacity