1. Impaired diffusing capacity and COPD incidence in adults with symptoms and normal spirometry.
- Author
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Tan DJ, Finlay P, Siu H, Fan IM, Hamilton GS, and King PT
- Abstract
Background: Impaired diffusing capacity of the lung (DLCO) in the absence of post-bronchodilator (BD) airflow obstruction has been proposed as a marker of 'Pre-COPD'. However, the relationship between impaired DLCO and subsequent lung function decline and COPD incidence has not been examined in-depth., Methods: We conducted an observational study of adults aged between 40 and 70 years who were evaluated at a multi-centre lung function laboratory in Australia between 2014 and 2024. Adults referred with respiratory symptoms or a clinical suspicion of obstructive airways disease with follow-up spirometry obtained ≥12 months after the initial assessment were included. The relationship between impaired DLCO and subsequent lung function decline and COPD incidence was assessed among those with normal spirometry at baseline., Results: A total of 266 patients with a mean age of 53.2 (SD 12.8) years were evaluated after a median follow-up of 2.3 [IQR 1.5 to 3.3] years. We found no evidence of an association between impaired DLCO (below the lower limit of normal) and annualised rate of decline in post-BD FEV
1 (MD -0.1 % predicted per-year, 95%CI -1.3 to 1.2), FVC (-0.4 % predicted, 95%CI -1.6 to 0.8) or FEV1 /FVC (-0.1 % per-year, 95%CI -0.1 to 0.1). The sensitivity of impaired DLCO for COPD incidence was 40 %, and specificity 82 %. Findings were similar in sub-samples limited to current and former smokers, and when impaired DLCO was defined as < 80 % predicted., Conclusion: Impaired DLCO was not an effective discriminator of lung function decline or COPD incidence in this real-world cohort., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)- Published
- 2024
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