Fig. 4
Level of FeNO (mean ± SD) at seven visits according to exercise frequency. The visits are ordered by the prior 6-h MA PM2.5 exposure (bottom). β, estimated change in the FeNO level per IQR increase in PM2.5 exposure in the LME models. The LME models are adjusted for ambient temperature and relative humidity. ** Significant difference in FeNO between subjects who exercise more and less than once per week by unpaired t-test