A comparison of Asian and white patients with obstructive sleep apnea syndrome

Objective: To evaluate the possible differences between Asian and white patients with obstructive sleep apnea syndrome, Methods: A retrospective review of Asian and white patients during a 12-month period was conducted. Patients with respiratory disturbance index (RDI) greater than or equal to 15 based on polysomnography were included in the study. Variables examined include age, sex, body mass index (BMI), RDI, lowest oxygen saturation (LSAT), and cephalometric analysis data. Results: Fifty-eight Asian patients (53 men) and 293 white patients (260 men) were studied, The Asians were younger (44.1 +/- 9.8 vs. 47.5 +/- 11.6 y, P = .02), and the mean BMI (kg/m(2)) was 26.6 +/- 3.7 in the Asians and 30.7 +/- 5.9 in the whites (P < .001). The mean RDI was similar (56.6 +/- 34.9 vs. 55.6 +/- 26.9, P = NS), but the mean LSAT was lower in the whites (77.7 +/- 9.9% vs. 70.0 +/- 15.6%, P < .001). Based on the cephalometric data, the Asians have maxillomandibular protrusion, narrower cranial base angle, larger posterior airway space, and more superiorly positioned hyoid bone compared with the whites. Conclusions: Although male gender was found to be an important risk factor for obstructive sleep apnea syndrome in both Asian and white patients, obesity may be a less significant risk factor in the Asians because the majority of our Asian patients were non-obese. There was also variability in the craniomandibular factors that contributed to obstructive sleep apnea syndrome in the two groups.