%0 Journal Article %T Determination of a Cut-off Point for Exhaled Nitric Oxide in the Diagnosis of Asthma in an Iranian Population %J TANAFFOS (Respiration) %I National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran %Z 1735-0344 %A Borhani Fard, Mohammad %A Samet, Mohammad %A Salmani Nodoushan, Mojahede %A Mehrparvar, Amir Houshang %A Bahrami-Ahmadi, Amir %D 2021 %\ 04/01/2021 %V 20 %N 2 %P 150-155 %! Determination of a Cut-off Point for Exhaled Nitric Oxide in the Diagnosis of Asthma in an Iranian Population %K Cut-off Point %K Exhaled Nitric Oxide %K Asthma %R %X Background: Asthma is a major source of global social and economic burden; thus, its early detection is important. Measurement of fractional exhaled nitric oxide (FENO) has been used recently considered a good indicator of asthma and also a sensitive and non-invasive method for monitoring airway inflammation. This study was conducted to determine the cut-off point of FENO for the diagnosis of asthma in the studied population. Materials and Methods: The subjects of this cross-sectional diagnostic study were assessed by the FENO test, spirometry, and methacholine challenge test. The best cut-off point of the FENO for the diagnosis of asthma was determined. The data were analyzed by SPSS 20 using student t-test, and Chi-square test and the ROC curves were also drawn. Results: The mean FENO in asthmatic and non-asthmatic subjects was 43.5±33.41 and 17.5±21.48 ppb, respectively (P <0.001). The best cut-off point of the FENO based on the overall sensitivity and specificity was 39.5 ppb. Conclusion: According to the results of this study, symptomatic patients with FENO higher than 39.5 ppb could be considered as asthmatic. %U https://www.tanaffosjournal.ir/article_248075_a61cc36ec9095a6255634cdcfba2dc10.pdf