Correlating Nasal Patency with Obstructive Sleep Apnea in Obese Versus Non-Obese Patients: An Acoustic Rhinometry Study

The aim of this study was to correlate nasal patency with Obstructive Sleep Apnea (OSA) in obese versus non-obese patients using Acoustic Rhinometry (AR). Eccovision (R) Acoustic Rhinometer equipment was used to compare nasal cross-sectional areas (CSA1,2 & 3 corresponding to nasal valve region, anterior portion of middle & inferior turbinate and posterior portion of middle & inferior turbinate respectively) and volume in age and gender matched sample divided into three groups: Group 1: Non-obese patients without OSA (25 patients, 13 males and 12 females); Group 2: Non-obese patients with OSA (25 patients, 14 males and 11 females); Group 3: Obese patients with OSA (25 patients, 13 males and 12 females). The mean nasal cross-sectional areas and volume were lower in Group 2 compared to Group 1 but statistically non-significant (P value > 0.05 for all). The mean nasal cross-sectional areas and volume were significantly lower in Group 3 as compared to Groups 1 and 2 (P value < 0.05 for all). BMI showed a statistically significant positive (direct) correlation with AHI in Groups 2 and 3 (P value < 0.05 for both). The nasal cross-sectional areas and volume showed a statistically significant negative (inverse) correlation with AHI in Groups 2 and 3 (P value < 0.05 for both). OSA diagnosed cases with high BMI may not present with an obvious nasal obstruction; the nasal patency may still be compromised due to reduced nasal lumen secondary to obesity. AR, being cost-effective and non-invasive modality; is advocated to evaluate pre-treatment nasal patency, as well as follow up evaluation to ascertain improvement after the intervention.