Cardiopulmonary Exercise Testing in the Early Diagnosis of COPD

Objective: Tobacco smoke is the most important factor in the etiology of chronic obstructive pulmonary disease (COPD). Even in developed countries, COPD is among the leading causes of death. Early diagno­sis of COPD is crucial to decrease rates of morbidity and mortality. Can COPD be recognized by exercise testing before air flow limitation is diagnosed by pulmonary function tests (PFTs)? This study sought to evaluate the role of cardiopulmonary exercise testing in ex-smokers as an early parameter for diagnosing COPD.

Methodology: Fourteen healthy nonsmokers with normal PFTs (group 1) and 30 ex-smoker GOLD stage 0 COPD patients (group 2) were included in our study. The patients’ FEV1 values and FEV1/FVC ratios were normal. The subjects in group 2 had smoked cigarettes for more than 10 pack-years. All subjects underwent PFTs and symptom-lim­ited cardiopulmonary exercise testing (CPET) using a treadmill.

Results: Analyses were performed to determine whether there was a significant difference between groups 1 and 2 with regard to maxi­mum oxygen uptake, breathing reserve, oxygen saturation, maximum minute ventilation, maximum voluntary volume, metabolic equivalent, inspiratory capacity, end expiratory lung volume and heart rate. There was a statistically significant difference in maximum oxygen uptake between groups (p<0.05).

Conclusion: Our results demonstrated a mild decrease in maximum oxygen uptake in GOLD stage 0 COPD patients. In high-risk popula­tions, CPET may prove to be an important test in the early identifica­tion of COPD.