Determinants of severity of dyspnea in COPD

Severity of dyspnea in COPD patients with comparable FEV1 is highly variable. Aim: To compare clinical and functional parameters in COPD patients with varying dyspnea degree. Methods: 88 COPD outpatients (GOLD II) aged 42-80 years were studied. COPD symptoms, spirometry and body plethysmography parameters, bronchial hyperresponsiveness (BHR) to methacholine challenge and concentration of serum biomarkers were analyzed. Depending on a dyspnea level all patients were divided two groups: 1-group (MRC 0-2) - 48 patients, 2-group (MRC 3) - 40 patients. Determinants of differences of degree of dyspnea were identified by means discriminant analysis. Results: FEV1 values were similar in both groups (p = 0,58). Among clinical characteristics were defined a contribution to the difference of level dyspnea: COPD duration (F=22,8; p Patients of the 2-nd group (MRC 3) were older (p = 0,042) and their COPD duration was 2,2 times longer (p Conclusion: Significant dyspnea-related differences in COPD II patients is based mainly on COPD duration, exacerbations frequency, BHR, RV and age of patients.