早发型和晚发型老年哮喘及老年慢性阻塞性肺疾病的FeNO变化及意义

The application value and variation of fractionted exhaled nitric oxide in long-standing asthma,late onset asthma and COPD in the aged

目的:比较早发型老年哮喘(LSA)、晚发型老年哮喘(LOA)及老年慢性阻塞性肺疾病(COPD)患者呼出气一氧化氮(Fe NO)的差异和意义。方法:选取2016年1月至2018年6月于温州医科大学附属第二医院育英儿童医院门诊就诊的老年哮喘患者68例、老年COPD患者53例,以及无呼吸系统疾病健康体检的非吸烟老年人(对照组)34例为研究对象。老年哮喘组分为LSA组(发病年龄<60周岁)42例和LOA组(发病年龄≥60周岁)26例。检测老年哮喘组(LSA组及LOA组)、COPD组及对照组的FeNO值和肺功能(FEV1/pred%、FEV1/FVC),比较各组FeNO值的差异,分析FeNO与FEV1/pred%、FEV1/FVC的关系。结果:老年哮喘组FeNO值[(29.3±18.7)ppb]较COPD组[(13.5±7.0)ppb]、对照组[(13.1±8.6)ppb]明显升高(均P<0.05);COPD组与对照组Fe NO值差异无统计学意义(P>0.05)。LSA组FeNO值[(33.7±20.4)ppb]较LOA组[(22.3±12.9)ppb]明显升高(P<0.05),均高于对照组(P<0.05)。老年哮喘组(LSA组、LOA组)、COPD组的Fe NO水平与肺功能(FEV1/pred%、FEV1/FVC)均无显著相关性(P>0.05)。ROC曲线结果显示以Fe NO 35 ppb为截断值鉴别LSA和LOA的敏感度为41%,特异度为88%。结论:LSA患者的Fe NO水平高于LOA患者,均高于老年COPD,且Fe NO水平均与肺功能(FEV1/pred%、FEV1/FVC)无明显相关性,Fe NO水平不受肺功能影响,以35 ppb为截断值在一定程度上可辅助鉴别LSA和LOA,且可鉴别诊断老年哮喘和老年COPD。

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.