title: Obstructive sleep apnea: a canonical correlation of cephalometric and selected demographic variables in obese and nonobese patients.
abstract: One hundred male obstructive sleep apnea (OSA) patients were classified into 2 groups on the basis of body mass index (BMI): 43 nonobese (BMI < 30 kg/m2) and 57 obese (BMI > or = 30 kg/m2) patients. A comprehensive cephalometric analysis with a multivariate statistical method was performed in order to define the different principal components (PCs) of cervico-craniofacial skeletal and upper airway soft tissue morphology in each group and how they contributed to selected elements of the patient demographic data, ie, apnea-hypopnea index (AHI), nocturnal oxyhemoglobin saturation, and BMI. Thirty cephalometric variables of cervico-craniofacial skeletal morphology were reduced to 8 PCs describing 84.4% and 85.4% of the total variance in obese and nonobese OSA patients, respectively. Sixteen cephalometric variables of hyoid bone position and head posture were reduced to 4 PCs describing 84.4% and 85.9% of the total variance in obese and nonobese OSA patients, respectively. Twenty cephalometric variables of upper airway soft tissue morphology were reduced to 7 PCs describing 89.5% and 84.6% of the total variance in obese and nonobese OSA patients, respectively. For further analysis of PCs, a stepwise multiple regression analysis was chosen. Two dependent variables of interest are the minimal distance of the posterior pharyngeal airway space (PASmin) and AHI. PASmin accounted for 95.3% (obese OSA group) and 74.3% (nonobese OSA group) with 7 PCs and AHI for 46% with 3 PCs in both groups. Three canonical variables and their correspondents with different loadings were established differently for both OSA groups. A canonical correlation successfully clarified the complexity of simultaneous relationship of the relevant variables. These analyses are proved useful to demonstrate the relationship of cervico-craniofacial skeletal and upper airway soft tissue morphology and selected demographic data. This lays down a basis for understanding the complicated pathogenic components of obese and nonobese OSA patients.
authors.affiliation: Department of Orthodontics, Institute of Clinical Dentistry, University of Oslo, Norway. vivatt@yahoo.com
authors.forename: V
authors.initials: V
authors.lastname: Tangugsorn
authors.forename: O
authors.initials: O
authors.lastname: Krogstad
authors.forename: L
authors.initials: L
authors.lastname: Espeland
authors.forename: T
authors.initials: T
authors.lastname: Lyberg
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002508:Cephalometry; D002574:Cervical Vertebrae / Q000473:pathology; D005147:Facial Bones / Q000473:pathology; D006257:Head / Q000503:physiopathology; D006801:Humans; D006928:Hyoid Bone / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications; D010108:Oxyhemoglobins / Q000032:analysis; D010614:Pharynx / Q000473:pathology; D011187:Posture; D012044:Regression Analysis; D020181:Sleep Apnea, Obstructive / Q000209:etiology* / Q000473:pathology*; D014059:Tongue / Q000473:pathology; D014609:Uvula / Q000473:pathology
chemical_list: D010108:Oxyhemoglobins