Methods: We performed a retrospective review of medical records of asthma patients in our allergy clinic at a large, public hospital. Asthma patients who performed FENO measurements in the first month after our clinic acquired a FENO analyzer (NIOX VERO) were included. We looked for associations between FENO and Asthma Control Test (ACT) scores, percent-predicted FEV1 (%FEV1), and asthma medications.
Results: FENO was measured in 56 patients. The patients ranged from 6 to 57 years old. There were 26 AA children (46.5%), 18 AA adults (32%), 7 HA children (12.5%), and 5 HA adults (9%). FENO ranged from 4 to 190 ppb. The %FEV1 ranged from 46 to 135. FENO was negatively associated with both the pre and post-albuterol %FEV1 (r2=0.269, p=0.0001, and r2=0.1813, p=0.001, respectively). The negative association between FENO and pre-albuterol %FEV1 was stronger in adults (r2=0.403, p=0.001) than in children (r2=0.150, p=0.026). In adult patients with %FEV1<80, FENO was higher (67.3±14.5ppb) compared to adults with %FEV1≥80 (22.9±5.5ppb, p=0.005). FENO was not associated with ACT score or asthma medications.
Conclusions: In our inner-city minority asthma patients, elevated FENO is associated with lower lung function; a measure of asthma severity. Our findings extend previously reported results of the general population to an inner-city minority asthma population.