Different Craniofacial Characteristics Predict Upper Airway Collapsibility in Japanese-Brazilian and White Men.
BACKGROUND
OSA pathogenesis is complex and may vary according to ethnicity. The anatomic component predisposing to OSA is the result of the interaction between bony structure and upper airway soft tissues and can be assessed using passive critical closing pressure (Pcrit). We hypothesized that Japanese-Brazilians and whites present different predictors of upper airway collapsibility, suggesting different causal pathways to developing OSA in these two groups.


METHODS
Male Japanese-Brazilians (n = 39) and whites (n = 39) matched for age and OSA severity were evaluated by full polysomnography, Pcrit, and upper airway and abdomen CT scans for determination of upper airway anatomy and abdominal fat, respectively.


RESULTS
Pcrit was similar between the Japanese-Brazilians and the whites (-1.0 ± 3.3 cm H2O vs -0.4 ± 3.1 cm H2O, P = .325). The Japanese-Brazilians presented smaller upper airway bony dimensions (cranial base, maxillary, and mandibular lengths), whereas the whites presented larger upper airway soft tissue (tongue length and volume) and a greater imbalance between tongue and mandible (tongue/mandibular volume ratio). The cranial base angle was associated with Pcrit only among the Japanese-Brazilians (r = -0.535, P < .01). The tongue/mandibular volume ratio was associated with Pcrit only among the whites (r = 0.460, P < .01). Obesity-related variables (visceral fat, BMI, and neck and waist circumferences) showed a similar correlation with Pcrit in the Japanese-Brazilians and the whites.


CONCLUSIONS
Japanese-Brazilians and whites present different predictors of upper airway collapsibility. Although craniofacial bony restriction influenced Pcrit only in the Japanese-Brazilians, an anatomic imbalance between tongue and mandible volume influenced Pcrit among the whites. These findings may have therapeutic implications regarding how to improve the anatomic predisposition to OSA across ethnicities.
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil.
Fabiola
F
Schorr
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil.
Fabiane
F
Kayamori
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil.
Raquel P
RP
Hirata
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil.
Naury J
NJ
Danzi-Soares
Radiology Institute (InRad), Hospital das Clínicas, University of São Paulo School of Medicine, São Paul, Brazil.
Eloisa M
EM
Gebrim
Biomedical Engineering Laboratory, University of São Paulo, São Paulo, Brazil.
Henrique T
HT
Moriya
Department of Pulmonary and Critical Care Medicine, University of California San Diego, La Jolla, CA.
Atul
A
Malhotra
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil.
Geraldo
G
Lorenzi-Filho
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), University of São Paulo School of Medicine, São Paul, Brazil. Electronic address: prgenta@gmail.com.
Pedro R
PR
Genta
D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D001938:Brazil; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D007564:Japan; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology; D008437:Maxilla / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009333:Neck / Q000033:anatomy & histology*; D009765:Obesity; D009929:Organ Size; D010614:Pharynx / Q000000981:diagnostic imaging*; D012886:Skull / Q000473:pathology*; D019291:Skull Base / Q000000981:diagnostic imaging / Q000473:pathology; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014059:Tongue / Q000000981:diagnostic imaging* / Q000473:pathology*; D055105:Waist Circumference; D044465:White People; D055815:Young Adult
OSA; Pcrit; computed tomography; ethnicity