Bronchodilators fail in symptomatic smokers with preserved lung function, a new study reveals! Researchers aimed to investigate the effect of bronchodilators in tobacco-exposed symptomatic patients with preserved lung function.

Subjects with preserved lung function on spirometry (ratio of forced expiratory volume in 1 second [FEV1] to forced vital capacity [FVC] of ≥ 0.70 and FVC ≥ 70% of the anticipated value following bronchodilator usage), respiratory symptoms as determined by a COPD Assessment Test score of minimum 10 (scores range from 0-40, with greater scores indicating poor symptoms), and a smoking history of minimum 10 pack-years were randomly allocated to receive either Indacaterol (27.5 μg) plus Glycopyrrolate (15.6 μg) or placebo two times a day for 12 weeks.

The major endpoint was a minimum 4-point improvement in the St. George's Respiratory Questionnaire (SGRQ) score (scores range from 0-100, with greater values signifying worse health condition) following 12 weeks with no treatment failure (stated as an elevation in lower respiratory symptoms managed with a long-acting antibiotic agent, glucocorticoid, or inhaled bronchodilator).

Randomization of 535 volunteers was done. Notably, 144 of 244 (59.0%) in the placebo arm and 128 of 227 people (56.4%) in the intervention arm exhibited a minimum 4-point drop in SGRQ score (difference, -2.6 percentage points; adjusted odds ratio, 0.91) in the modified intention-to-treat population (471 subjects). Mean alteration in inspiratory capacity was 0.02 litres in the placebo group and 0.12 litres in the intervention group. Mean alteration in the percent of anticipated FEV1 was -0.09 percentage points in the placebo group and 2.48 percentage points in the intervention group.

In the intervention group, there were 4 major adverse events, whereas there were 11 in the placebo group; none of these were thought to be possibly connected to either the intervention or the placebo. Treatment with inhaled dual bronchodilators in symptomatic individuals exposed to tobacco did not report improvement in their respiratory symptoms.