The application value and variation of fractionted exhaled nitric oxide in long-standing asthma, late onset asthma and COPD in the aged
QUAN Duoduo1, LIU Xiao2, DAI Yuanrong3
1.Department of Pathology,the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027,China; 2.Department of Emergency Medicine and Critical Care Medicine, Wenzhou Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medical University, Wenzhou 325000, China; 3.Department of Respiratory Medicine,the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou325027, China
QUAN Duoduo,LIU Xiao,DAI Yuanrong. The application value and variation of fractionted exhaled nitric oxide in long-standing asthma, late onset asthma and COPD in the aged[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2020, 50(12): 961-965.
Abstract：Objective: To explore the significance of fractionted exhaled nitric oxide (FeNO) measurement in long-standing asthma (LSA), late onset asthma (LOA) and chronic obstructive pulmonary disease (COPD) and to compare their differences. Methods: Altogether 68 older adults with asthma, 53 with COPD, 34 healthy nonsmoking older adults were enrolled in the study from Jan 2016 to Jun 2018 who came to the Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University. In older adults with asthma, LSA or LOA was based on age of diagnosis (before or after age 60 year), 42 LSA and 26 LOA were recruited. The level of FeNO and pulmonary function (FEV1% pred, FEV1/FVC) was measured in older adults with asthma, older adults with COPD and healthy subjects. We analyzed the correlation between the level of FeNO and pulmonary function (FEV1/pred%, FEV1/FVC) in all groups. Results: FeNO of elderly asthmatic group [(29.3±18.7)ppb] was higher than elderly COPD group [(13.5±7.0)ppb] (P<0.05), also higher than healthy group [(13.1±8.6)ppb] (P<0.05). The difference in levels of FeNO between LSA [(33.7±20.4)ppb] and LOA [(22.3±12.9)ppb] was statistically significant (P<0.05). There was no correlation between FeNO level and pulmonary function (FEV1/pred%, FEV1/FVC) in all groups (P>0.05), and there’s no correlation between FeNO level and pulmonary function in LSA and LOA (P>0.05). FeNO>35 ppb was the best cutoff point to distinguish LSA from LOA, as the sensitivity was 41% and specificity was 88%. Conclusion: The level of FeNO in LSA is higher than in LOA and that of COPD. FeNO level can help clinicians distinguish elderly asthma from elderly COPD, and LSA from LOA. The best cutoff point is FeNO>35 ppb to differentiate LSA from LOA.
