Acoustic pharyngometry measurement of minimal cross-sectional airway area is a significant independent predictor of moderate-to-severe obstructive sleep apnea.
OBJECTIVE
The current gold-standard method of diagnosing obstructive sleep apnea (OSA) is polysomnography, which can be inefficient. We therefore sought to determine a method to triage patients at risk of OSA, without using subjective data, which are prone to mis-reporting. We hypothesized that acoustic pharyngometry in combination with age, gender, and neck circumference would predict the presence of moderate-to-severe OSA.


METHODS
Untreated subjects with suspected OSA were recruited from a local sleep clinic and underwent polysomnography. We also included a control group to verify differences. While seated in an upright position and breathing through the mouth, an acoustic pharyngometer was used to measure the minimal cross-sectional area (MCA) of the upper airway at end-exhalation.


RESULTS
Sixty subjects were recruited (35 males, mean age 42 years, range 21-81 years; apnea-hypopnea index (AHI) 33 ± 30 events/h (mean ± standard deviation), Epworth Sleepiness Scale score 11 ± 6, body mass index 34 ± 8 kg/m(2)). In univariate logistic regression, MCA was a significant predictor of mild-no OSA (AHI < 15). A multivariate logistic regression model including MCA, age, gender, and neck circumference significantly predicted AHI < 15, explaining approximately one-third of the total variance (χ(2)(4) = 37, p < 0.01), with only MCA being a significant independent predictor (adjusted odds ratio 54, standard error 130; p < 0.01).


CONCLUSIONS
These data suggest that independent of age, gender, and neck size, objective anatomical assessment can significantly differentiate those with mild versus moderate-to-severe OSA in a clinical setting, and may have utility as a component in stratifying risk of OSA.
Division of Pulmonary and Critical Care, University of California San Diego, San Diego CA ; Division of Sleep Medicine, Brigham and Women's Hospital & Harvard Medical School, Boston, MA.
Pamela N
PN
Deyoung
Jessie P
JP
Bakker
Scott A
SA
Sands
Salma
S
Batool-Anwar
James G
JG
Connolly
James P
JP
Butler
Atul
A
Malhotra
D000162:Acoustics; D000328:Adult; D001837:Body Weights and Measures / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010614:Pharynx / Q000033:anatomy & histology* / Q000503:physiopathology*; D017286:Polysomnography / Q000379:methods / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D015599:Trauma Severity Indices
Acoustic pharyngometry; airway; lung; obstructive sleep apnea; sleep