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Nine out of 10 people with GOLD stage 1 chronic obstructive pulmonary disease (COPD) do not have lung disease and are not at substantially increased risk of developing lung disease during the next decade. The SAPALDIA investigators recently described the outcomes after 11 years of follow-up of 519 adults with GOLD stage 1 COPD, comparing them with 6061 with normal spirometry.1 More than one-third of these adults, both at the baseline and follow-up examinations, would have had normal spirometric results if the investigators had used the appropriate lower limit of the normal range for the ratio of the forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) instead of a fixed 0.70,2 and had taken the time to measure post-bronchodilator spirometry.3 About half of those with GOLD stage 1 COPD at the baseline examination (N = 224) reported either a chronic cough, chronic phlegm, chronic bronchitis or dyspnoea. However, in adults with a normal FEV1 (especially in never-smokers), these non-specific symptoms are usually not due to COPD. A chronic cough is often due to gastro-oesophageal reflux (often due to obesity) or asthma (not yet diagnosed by a doctor). Chronic phlegm is often due to rhinosinusitis with postnasal drainage. Dyspnoea with a normal FEV1 is usually due to cardiac deconditioning, obesity or over-reporting, and sometimes is caused by undiagnosed cardiovascular disease such as congestive heart failure.
I suspect that their slightly increased utilisation of respiratory care during the 12 months before the year 11 follow-up was due to asthma (diagnosed subsequent to their baseline visit), viral upper respiratory infections, hay fever or cardiovascular disease, and never due to a true COPD exacerbation. Their lung function simply could not have fallen enough during the 11 years (with a mean decline of 440 ml from a mean FEV1 of 99% predicted) to have caused a COPD exacerbation. As with the 11-year follow-up of the Lung Health Study cohort of adult smokers with an FEV1/FVC <0.70, fewer than 10% of those with a baseline FEV1 above 80% predicted had developed a post-bronchodilator FEV1 below 60% predicted.4
Smokers with normal or near-normal FEV1 should be urged and helped to quit smoking, not given a diagnostic label of “COPD” which risks inappropriate treatments.5 Other causes for their chronic cough, phlegm and dyspnoea should be sought.
Competing interests: None.
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