Do not be too quick to discount chronic bronchitis symptoms and their association with the development of COPD, a UK expert has told delegates at the virtual American Thoracic Society 2020 conference.
Dr James Allinson, consultant respiratory physician at the Royal Brompton Hospital in London and honorary senior clinical lecturer at Imperial College London said despite the removal of GOLD grade 0 in the updated 2020 guidelines, chronic symptoms in some patients do reflect an increased chance of developing COPD.
He told the conference that GOLD 0 was meant to identify patients who did not have COPD but chronic symptoms such as chronic cough and sputum production that put them at risk.
Yet it was dropped because definitively linking chronic symptoms had proven difficult and studies such as the Copenhagen City Heart study not only found no link but that most cases developed in those who did not fall into the GOLD 0 category.
But that is not the end of the story, he argued, because the actual picture is more nuanced than a simple binary phenotype.
Age is the key factor, he said in his presentation, as well as persistence of symptoms.
Research has shown a clear link between chronic bronchitis and increased later risk of airflow limitation in the under 50s but not in those over 50, he said.
And data from the UK 1946 cohort shows a similar pattern in people in their 30s and 40s, where the prevalence of chronic sputum production increased among persistent smokers, with chronic symptoms identifying a heightened risk of airflow limitation by age 60.