PURPOSE: The significance of bronchodilator responsiveness in patients with Chronic Obstructive Pulmonary Disease (COPD) is unclear. We hypothesized that it is associated with an underlying atopic state.
METHODS: This was a retrospective chart review of 100 consecutive COPD patients who had a bronchodilator challenge during spirometry. Demographics, smoking status, past medical history including history of allergies, skin atopy or asthma, pre and post bronchodilator spirometry, medications, and exacerbations rate were recorded. Patients were divided in two groups responders vs. non responders. Responders were subjects who demonstrated a positive bronchoreactivity defined as an either increase in Forced Expiratory Volume in 1 second (FEV1) or Forced Vital Capacity (FVC) by 200 ml and 12%. Atopic state was defined as any history of allergic rhinitis, asthma or skin atopy. Comparison was made using Chi-square and Mann-Whitney U tests. Results are expressed as percentage and mean ± standard deviation.
RESULTS: Demographics, smoking status, and medications (including inhaled corticosteroids) were similar between groups. Responders (n=56) demonstrated a more severe obstructive dysfunction compared to non responders (%FEV1 40.6±14.3 vs. 55.8±19.6, p<0.01). Atopic state tended to be more prevalent in the responders group (73% vs. 65%) but there was no significant difference between groups in reported history of allergic rhinitis (OR 1.02, 95% CI 0.45-2.34; p=0.9), asthma (OR 1.48, 95% CI 0.62-3.50; p=0.4) or skin atopy (OR 1.06, 95% CI 0.40-2.06; p=0.9). Exacerbations rate was also comparable between groups with no significant difference detected in responders vs. non responders (OR 1.25, 95% CI 0.45-2.84; p=0.6).
CONCLUSION: Although atopic state was prevalent in this cohort of patients, bronchoreactivity was not associated with an increased risk for asthma, allergic rhinitis or skin atopy in patients with COPD.
CLINICAL IMPLICATIONS: Bronchodilator responsiveness during spirometry in COPD cannot be explained by an underlying allergy state.
DISCLOSURE: Omar Nehme, No Financial Disclosure Information; No Product/Research Disclosure Information