Craniofacial profile in Asian and white subjects with obstructive sleep apnoea

• Published in: Thorax Vol. 60; no. 6; pp. 504 - 510
• Main Authors: Lam, B, Ip, M S M, Tench, E, Ryan, C F
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Thoracic Society 01-06-2005; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: AHI; Airway management; Analysis of Variance; apnoea-hypopnoea index; Asian Continental Ancestry Group - ethnology; Biological and medical sciences; BMI; Body mass index; British Columbia - ethnology; Cephalometry - standards; craniofacial structure; Craniology; Ethnicity; European Continental Ancestry Group - ethnology; Face - pathology; Female; Hong Kong - ethnology; Humans; Male; Mallampati score; Measurement techniques; Medical sciences; Middle Aged; neck circumference; obstructive sleep apnoea; obstructive sleep apnoea-hypoponea syndrome; Oropharynx; OSA; OSAHS; Patients; Pneumology; prediction equations; Prospective Studies; Respiratory system : syndromes and miscellaneous diseases; Sensitivity and Specificity; Skull - pathology; Sleep apnea; Sleep Apnea, Obstructive - ethnology; Sleep Apnea, Obstructive - pathology; sleep apnoea; Sleep Disordered Breathing; Statistical analysis; Thyroid gland; thyromental angle; thyromental distance; TMA; TMD; upper airway; Variables; Hong Kong; British Columbia; Human; Nervous system diseases; Sleep apnea syndrome; Respiratory disease; Cardiovascular disease; Craniofacial; Profile
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thx.2004.031591

Background: Clinical detection of structural narrowing of the upper airway may facilitate early recognition of obstructive sleep apnoea (OSA). To determine whether the craniofacial profile predicts the presence of OSA, the upper airway and craniofacial structure of 239 consecutive patients (164 Asian and 75 white subjects) referred to two sleep centres (Hong Kong and Vancouver) were prospectively examined for suspected sleep disordered breathing. Methods: All subjects underwent a history and physical examination with measurements of anthropometric parameters and craniofacial structure including neck circumference, thyromental distance, thyromental angle, and Mallampati oropharyngeal score. OSA was defined as an apnoea-hypopnoea index (AHI) of ⩾5/hour on full overnight polysomnography. Results: Discriminant function analysis indicated that the Mallampati score (F = 0.70), thyromental angle (F = 0.60), neck circumference (F = 0.54), body mass index (F = 0.53), and age (F = 0.53) were the best predictors of OSA. After controlling for ethnicity, body mass index and neck circumference, patients with OSA were older, had larger thyromental angles, and higher Mallampati scores than non-apnoeic subjects. These variables remained significantly different between OSA patients and controls across a range of cut-off values of AHI from 5 to 30/hour. Conclusions: A crowded posterior oropharynx and a steep thyromental plane predict OSA across two different ethnic groups and varying degrees of obesity.