Are reduced internal nasal dimensions a risk factor for obstructive sleep apnea syndrome?

INTRODUCTION: Obstructive sleep apnea syndrome is a high-prevalence disorder found in the population. Studies have shown a possible association between nasal obstruction and obstructive sleep apnea syndrome, but the existence of a association between the degree of nasal obstruction and obstructive sleep apnea syndrome severity has not yet been proven. OBJECTIVE: To evaluate the internal nasal dimensions of adults with primary snoring and obstructive sleep apnea syndrome by acoustic rhinometry and to correlate the findings with obstructive sleep apnea severity. METHODS: Twenty-one male Caucasian subjects with complaints of snoring and/or respiratory pauses during sleep, aged between 18 and 60 years of age, were evaluated. After clinical evaluation, otorhinolaryngological examination and flexible nasopharyngolaryngoscopy, all patients underwent type III polysomnography. The participants were divided into two groups according to symptom severity: group 1, primary snoring and/or mild obstructive sleep apnea syndrome(n = 9) and group 2, moderate/severe obstructive sleep apnea syndrome (n = 12). Internal nasal dimensions were measured by acoustic rhinometry, analyzing minimum cross sectional area (CSA) and three nasal segment volumes. RESULTS: The respiratory event index corresponded to 8.1 ± 4.0 in group 1 and 47.5 ± 19.1 in group 2. In group 1, the cross-sectional areas values, in cm2, corresponded to: CSA 1 = 1.1 ± 0.4; CSA 2 = 2.1 ± 0.9; CSA 3 = 3.5 ± 1.8 and, in group 2: CSA 1 = 1.2 ± 0.3, CSA 2 = 2.0 ± 0.5; CSA 3 = 2.8 ± 0.7. In group 1, volumes (V), in cm3, corresponded to: V1 = 3.5 ± 1.0; V2 = 9.3 ± 5.0; V3 = 40.2 ± 21.5 and in group 2 a: V1 = 3.6 ± 0.5; V2 = 7.6 ± 1.5; V3 = 31.5 ± 6.7. Cross-sectional area and volume ​​did not differ between groups. CONCLUSION: There were no significant differences in the cross-sectional areas and nasal volumes between individuals with primary snoring-mild obstructive sleep apnea syndrome and moderate-severe obstructive sleep apnea syndrome. Differently to the raised hypothesis, our results suggest that there is no association between internal nasal dimensions and severity of obstructive sleep apnea syndrome.