Chronic cough in asthma linked to more severe disease
Among patients with asthma, those with chronic cough vs. without chronic cough had worse respiratory symptoms, more health care use, lower lung function and higher levels of inflammatory biomarkers, according to a Danish study published in the Journal of Allergy and Clinical Immunology: In Practice.
Specifically, patients with asthma and chronic cough, as compared with those with asthma but without chronic cough, experienced more wheezing (70% vs. 54%; P < .05), dyspnea (74% vs. 49%; P < .005), night-time dyspnea (27% vs. 11%; P < .001), sputum production (59% vs. 14%; P < .005) and chest pain or tightness (14% vs. 4%; P < .005).
Additionally, patients with asthma and chronic cough vs. without chronic cough were more likely to have had acute bronchitis and/or pneumonia at least six times in the last 10 years (21% vs. 10%; P < .005) and were more likely to have visited a general practitioner at least three times in the past 12 months (60% vs. 45%; P < .05).
In patients with asthma and chronic cough vs. without chronic cough, FEV1 predicted values less than 60% were also more common (14% vs. 7%), as were higher levels of blood neutrophils, blood leukocytes and plasma fibrinogen. However, levels of plasma high-sensitive C-reactive protein, blood eosinophils and plasma immunoglobulin E did not differ significantly between patients with asthma and chronic cough compared with those with asthma but without chronic cough.
“The results show that chronic cough in individuals with asthma is associated with a more severe disease phenotype,” the researchers wrote.
For the study, the researchers evaluated 14,740 adults from the Copenhagen General Population Study. Of these people, 6% had asthma, as defined by a positive response to a question asking whether the person had asthma, and 8% had chronic cough, as defined by a positive response to whether the person had had a cough lasting longer than 8 weeks. Patients with asthma were also asked about how long they had had asthma and medication use. – by Melissa Foster
Disclosures: One author reports receiving personal fees from AstraZeneca and Boehringer Ingelheim. A second author reports he has received grants from AstraZeneca and GlaxoSmithKline, and he has received personal fees from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline and Novartis. All other authors report no relevant financial disclosures.