In healthy subjects nasal nitric oxide does not correlate with olfactory sensitivity, trigeminal sensitivity, and nasal airflow

Abstract

The aim of the study was to determine the relationship between nasal nitric oxide (nNO) and olfactory sensitivity, trigeminal sensitivity and nasal airflow in healthy subjects. This is a correlational study. This study was carried out in a tertiary referral centre. Forty healthy participants were recruited. nNO was measured using a chemiluminescence analyser (Niox Vero® , CircassiaAB, Uppsala, Sweden), olfactory sensitivity was determined using phenyl ethyl alcohol odour thresholds using the 'Sniffin' Sticks', trigeminal sensitivity was assessed with carbon dioxide delivered by an automated device, and nasal airflow was measured using the peak nasal inspiratory flow (PNIF). The median nNO was 518ppb (IQR=333) in the right nostril, and it was 567ppb (IQR=314) in the left nostril. The median odour threshold was 7.1 (IQR=4.4), the median CO2 threshold was 919ms (IQR=1297) and the mean PNIF was 108L/min (SEM=4.9). nNO did not correlate significantly with odour threshold, CO2 threshold or PNIF (Spearman's|ρ| <0.15, p>.18). In healthy subjects, nNO does not appear to be associated with olfactory sensitivity, trigeminal sensitivity and PNIF.