Patients with mild to moderate COPD plus elevated eosinophils risk a more rapid decline in lung function after exacerbations than those with lower eosinophil counts, researchers say.

But, in a prospective observational study published in Thorax, they have also found the decline can be mitigated if inhaled corticosteroids (ICS) are used as part of maintenance therapy.

The research, funded by pharmaceutical company AstraZeneca and including employees as authors, drew on records from more than 12,000 people in two UK primary care databases followed for a median of six years.

All had mild or moderate COPD, were aged over 35 years and had a history of smoking. Some 52% were men and 74% were on maintenance therapy that included ICS.