Patients with COPD carry much higher levels of glucose in their airways, increasing the growth of bacteria and consequently the risk of infections, according to researchers from Imperial College London.

Their study, “Role of airway glucose in bacterial infections in patients with chronic obstructive pulmonary disease,” was published in the Journal of Allergy and Clinical Immunology.

In a normal status, the levels of glucose in the airway surface liquid (ASL) — a thin liquid layer that lies between the airway epithelium and the gas in the lumen, and that is vital for maintaining bacteria-free lungs and facilitate mucus clearance — are about 12 times lower than glucose concentrations in the blood.