“…Although we had a relatively small sample size, the association between FeNO and self-reported respiratory symptoms indicates that we may have accurately captured airway inflammation as it relates to the presence of symptoms [ 39 , 58 ]. While we did not see an association between FeNO and age or FeNO and height, as we would have expected based on previous literature, [ 38 , 39 , 58 , 59 , 60 ], this may be due to the relatively small range of age and height in our study. For example, our study population only covered adults age 25–56 (mean 37.1 years, SD: 9.1 years).…”