Exercise capacity and gas exchange in smokers with discordant GOLD vs FEV1/FVC lower limit of normal (LLN) airway obstruction diagnosis

Background: GOLD criteria (FEV1/FVC Results: Smokers N according GOLD but with AO for LLN showed, respect to normal GOLD/LLN concordant, lower V’O2peak 1.1+0.3 vs 1.4+0.5 L/min p Smokers AO for GOLD but N for LLN, respect to AO concordant GOLD/LLN, were younger with lower MRC dyspnea 0.3+0.6 vs 1.4+1.2, higher FEV1 88.3+1.9 vs 76+17 %pred p Conclusions: Smokers normal according GOLD but with AO according LLN showed early mechanical impairment and reduction in exercise capacity and gas exchange. On the other hand smokers with AO according GOLD but normal according to LLN had lower dyspnea, little mechanical impairment and better exercise capacity. These data confirm that LLN criteria are better correlated to clinical conditions and help to identify COPD patients with early impairment .