Correlation of fractional exhalation of nitric oxide values with asthma control test score and spirometric parameters in steroid naïve asthmatic children at 6-8 weeks follow up.

Abstract

In pediatric asthma, it is critical to have a reliable airway inflammation marker that may be used to assess its severity and prognosis. Fractional exhalation of nitric oxide (FeNO) is a non-invasive objective method can be utilized as a supplemental tool if proven to correlate with clinical parameters. To study the correlation between FeNO, and asthma control test (ACT) scores and spirometry data in steroid naive asthmatic children 6-18 years at visit one and after 6-8 weeks follow-up. This was observational follow-up study conducted among steroid naïve asthmatics attending the Outpatient Department. At baseline visit, they were classified as well controlled, not well controlled, and poorly controlled as per ACT, FeNO and Spirometry done as per standard technique. After 6-8 weeks of follow-up, all the above parameters were repeated. Pearson correlation coefficient/Kendall's tau 2 of 10 analysis was used for the association of two related variables. <i>P</i> <0.05 was considered statistically significant. Among 56 enrolled, mean FeNO at visit 1 was 41.8 ± 33.26, which decreased to 20.26 ± 14.57 at visit 2. Changes in mean FeNO values between both visits and ΔACT scores (<i>P</i> = -0.001) and change in forced expiratory volume in 1 sec (ΔFEV1) were statistically significant (<i>P</i> = 0.001). A decrease in FeNO values from baseline was accompanied by significant increase in ACT scores and an improvement in FEV1. The FeNO values correlated inversely with the ACT scores as well as FEV1 proving its scope for incorporating it in the clinical setting for monitoring asthma treatment.