Characteristics associated with respondersto an external nasal dilator strip: A preliminary study

We have previously shown that wearing an external nasal dilator strip (ENDS) device (Breathe Right8, 3M Co.) significantly lowers inspiratory nasal resistance to airflow (Rn) in some subjects (responders) but not in others (non-responders). In the present preliminary study we examine characteristics associated with being a responder to ENDS. Methods: A data base was compiled containing information pertaining to 76 subjects who had previously undergone studies with ENDS in our laboratory. Data recorded included: anthropométrie measurements - age, height, weight, BMI, gender, racial origin (n=62-76); Rn (measured via posterior rhinomanometry) with and without ENDS (n=76); Rn following topical nasal decongestant (n=49); questionnaire responses including current and past history related to smoking, snoring, sleep apnoea, nasal or other upper airway disease and asthma (n=25-38); measurements of external nasal dimensions using calipers (n=44); and measurements of nasal valve crosssectional area using acoustic rhinometry (n=28). A response to ENDS was defined as a significant within subject decrease in Rn with ENDS (p<0.05, unpaired t test). Logistic regression analysis was used to search for associations between the occurrence of a response to ENDS and individual characteristics recorded in the data base. Results: Twenty three subjects met the criteria for a response to ENDS while the remaining 53 subjects were classified as non-responders. Significant negative associations were detected between the occurrence of a response to ENDS and: 1) measures of nasal width (p<0.009); 2) external nasal cross- sectional area (p=0.021); 3) left nasal valve cross-sectional area (p=0.025); and 4) the relative magnitude of the decrease in Rn with nasal decongestant (p<0.04). Positive associations were detected for age (p=0.016) and a history of 'snoring often' (p=0.025). Conclusion: We conclude that older snorers, with externally and internally smaller noses and a poor relative response to nasal decongestant, are more likely to be ENDS responders. Furthermore, we speculate that non-vascular related nasal lumen narrowing appears more likely to be responsive to ENDS than narrowing related to nasal mucosal congestion.