Chronic mucus hypersecretion is associated with worse current clinical control in smokers and more exacerbations in never smokers, according to new research published in Respiratory Medicine.

The study analyzed cross-sectional data from 120 smokers and never smokers with asthma. Participants with and without a history of chronic mucus hypersecretion were compared for clinical outcomes, sputum differential cell counts and CT measures of airway dimensions.

According to the results, chronic mucus hypersecretion occurred in a higher proportion of smokers with asthma (56%) than never smokers with asthma (20%), and the proportion of patients with these symptoms increased with asthma severity.

In addition, smokers with asthma and chronic mucus hypersecretion had worse current clinical control than smokers without those symptoms. Smokers with severe asthma and chronic mucus hypersecretion were also found to have a reduced CT measure of airway lumen area compared to never smokers (11.4 mm2 versus 18.4 mm2).

“Smokers with asthma are known to have worse ACQ scores than never smokers with asthma and possibly a history of chronic mucus hypersecretion adversely effects the perception of symptoms in this sub-group of patients, particularly in those with severe disease,” according to the authors.