Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms
Early identification of subjects running an increased risk of contracting COPD enables focus on individual preventive measures. The slope of the alveolar plateau of the single-breath nitrogen washout test (N2-slope) is a sensitive measure of small-airway dysfunction. However, its role remains unexpl...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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European Respiratory Society
2021-09-01
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| Series: | ERJ Open Research |
| Online Access: | http://openres.ersjournals.com/content/7/3/00383-2021.full |
| _version_ | 1818716563839123456 |
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| author | Jan Olofson Björn Bake Bengt Bergman Lowie E.G.W. Vanfleteren Kurt Svärdsudd |
| author_facet | Jan Olofson Björn Bake Bengt Bergman Lowie E.G.W. Vanfleteren Kurt Svärdsudd |
| author_sort | Jan Olofson |
| collection | DOAJ |
| description | Early identification of subjects running an increased risk of contracting COPD enables focus on individual preventive measures. The slope of the alveolar plateau of the single-breath nitrogen washout test (N2-slope) is a sensitive measure of small-airway dysfunction. However, its role remains unexplored in predicting hospital admission or death related to COPD, i.e. incident COPD events, in relation to the presence of various respiratory symptoms. A random population sample of 625 men, aged 50 (n=218) or 60 years (n=407), was followed for 38 years for incident COPD events. At baseline, a questionnaire on respiratory symptoms and smoking habits was collected, spirometry and the single-breath nitrogen test were performed, and the N2-slope was determined. Proportional hazard regression (Cox regression) analysis was used for the prediction model. The N2-slope improved the prediction of COPD events significantly beyond that of respiratory symptoms weighted all together and other covariates (hazard ratio 1.63, 95% CI 1.20–2.22; p<0.005), a prediction applicable to subjects without (p=0.001) and with (p<0.05) airway obstruction. Dyspnoea and wheezing were the most predictive symptoms. The combination of the N2-slope and number of respiratory symptoms notably resulted in an effective prediction of incident COPD events even in nonobstructive subjects, as evidenced by a predicted incidence of ∼70% and ∼90% for a very steep N2-slope combined with many respiratory symptoms in subject without and with airway obstruction, respectively. The alveolar N2-slope should be considered in the critical need for further research on early diagnosis of COPD. |
| first_indexed | 2024-12-17T19:21:15Z |
| format | Article |
| id | doaj.art-da8040d132114821ac88ac6967eb63a5 |
| institution | Directory Open Access Journal |
| issn | 2312-0541 |
| language | English |
| last_indexed | 2024-12-17T19:21:15Z |
| publishDate | 2021-09-01 |
| publisher | European Respiratory Society |
| record_format | Article |
| series | ERJ Open Research |
| spelling | doaj.art-da8040d132114821ac88ac6967eb63a52022-12-21T21:35:33ZengEuropean Respiratory SocietyERJ Open Research2312-05412021-09-017310.1183/23120541.00383-202100383-2021Prediction of COPD by the single-breath nitrogen test and various respiratory symptomsJan Olofson0Björn Bake1Bengt Bergman2Lowie E.G.W. Vanfleteren3Kurt Svärdsudd4 Unit of Respiratory Medicine and Allergology, Dept of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Unit of Respiratory Medicine and Allergology, Dept of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Unit of Respiratory Medicine and Allergology, Dept of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden COPD Center, Institute of Medicine, Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden Dept of Public Health and Caring Sciences, Family Medicine and Preventive Medicine Section, Uppsala University, Uppsala, Sweden Early identification of subjects running an increased risk of contracting COPD enables focus on individual preventive measures. The slope of the alveolar plateau of the single-breath nitrogen washout test (N2-slope) is a sensitive measure of small-airway dysfunction. However, its role remains unexplored in predicting hospital admission or death related to COPD, i.e. incident COPD events, in relation to the presence of various respiratory symptoms. A random population sample of 625 men, aged 50 (n=218) or 60 years (n=407), was followed for 38 years for incident COPD events. At baseline, a questionnaire on respiratory symptoms and smoking habits was collected, spirometry and the single-breath nitrogen test were performed, and the N2-slope was determined. Proportional hazard regression (Cox regression) analysis was used for the prediction model. The N2-slope improved the prediction of COPD events significantly beyond that of respiratory symptoms weighted all together and other covariates (hazard ratio 1.63, 95% CI 1.20–2.22; p<0.005), a prediction applicable to subjects without (p=0.001) and with (p<0.05) airway obstruction. Dyspnoea and wheezing were the most predictive symptoms. The combination of the N2-slope and number of respiratory symptoms notably resulted in an effective prediction of incident COPD events even in nonobstructive subjects, as evidenced by a predicted incidence of ∼70% and ∼90% for a very steep N2-slope combined with many respiratory symptoms in subject without and with airway obstruction, respectively. The alveolar N2-slope should be considered in the critical need for further research on early diagnosis of COPD.http://openres.ersjournals.com/content/7/3/00383-2021.full |
| spellingShingle | Jan Olofson Björn Bake Bengt Bergman Lowie E.G.W. Vanfleteren Kurt Svärdsudd Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms ERJ Open Research |
| title | Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms |
| title_full | Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms |
| title_fullStr | Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms |
| title_full_unstemmed | Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms |
| title_short | Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms |
| title_sort | prediction of copd by the single breath nitrogen test and various respiratory symptoms |
| url | http://openres.ersjournals.com/content/7/3/00383-2021.full |
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