@article {Brander398, author = {PE Brander and IL Mortimore and NJ Douglas}, title = {Effect of obesity and erect/supine posture on lateral cephalometry: relationship to sleep-disordered breathing}, volume = {13}, number = {2}, pages = {398--402}, year = {1999}, doi = {10.1183/09031936.99.13239899}, publisher = {European Respiratory Society}, abstract = {Craniofacial and upper airway anatomy, obesity and posture may all play a role in compromising upper airway patency in patients with the sleep apnoea/hypopnoea syndrome. The aim of this study was to investigate the relationship between obesity, facial structure and severity of sleep-disordered breathing using lateral cephalometric measurements and to assess the effect of body posture on cephalometric measurements of upper airway calibre variables in obese and non-obese subjects. Lateral cephalometry was carried out in erect and supine postures in 73 awake male subjects randomly selected from patients referred for polysomnography who had a wide range of apnoea/hypopnoea frequencies (1-131 events x h sleep(-1)). Subjects were divided into non-obese (body mass index (BMI) \< 30 kg x m(-2); n=42) and obese (BMI \> or = 30 kg x m(-2); n=31) groups. Significant but weak correlations were found between apnoea/hypopnoea index (AHI) and measurements reflecting upper airway dimensions: uvular protrusion-posterior pharyngeal wall (r=-0.26, p\<0.05) and hyoid-posterior pharyngeal wall (r=0.26, p\<0.05). Multiple regression using both upper airway dimensions improved the correlation to AHI (r=0.34, p=0.01). Obese subjects had greater hyoid-posterior pharyngeal wall distances than non-obese subjects, both erect (42+/-5 versus 39+/-4 mm, respectively (mean+/-SD) p\<0.01) and supine (43+/-5 versus 40+/-4 mm, p\<0.05). Skeletal craniofacial structure was similar in obese and non-obese subjects. In conclusion, measurements reflecting upper airway size were correlated with the severity of sleep-disordered breathing. Differences in upper airway size measurements between obese and non-obese subjects were independent of bony craniofacial structure.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/13/2/398}, eprint = {https://erj.ersjournals.com/content/13/2/398.full.pdf}, journal = {European Respiratory Journal} }