Differences in Cardiopulmonary Exercise Test Results by American Thoracic Society/European Respiratory Society-Global Initiative for Chronic Obstructive Lung Disease Stage Categories and Gender

Background The American Thoracic Society (ATS)/European Respiratory Society (ERS)-Global Initiative for Chronic Obstructive Lung Disease (GOLD) has developed a new staging system based on the degree of airflow obstruction. Its validity to predict exercise capacity as an outcome has not been extensively studied. We hypothesized that exercise performance measured by cardiopulmonary exercise test (CPET) results should decline significantly with each disease stage, independent of gender. Methods We examined 453 consecutive incremental CPET and pulmonary function tests performed in patients who had been referred to a single respiratory physiology laboratory in a tertiary care hospital. They were divided into a control group (normal lung function) and ATS/ERS-GOLD stages 1 to 4. We measured anthropometrics, peak work (in watts), peak oxygen uptake (in liters per kilogram per minute and percent predicted), breathing reserve (in percent predicted), and arterial blood gas response. We compared these results between different stages and genders. Results The mean (± SD) age for the entire group was 64 ± 11 years, the mean FEV 1 was 66 ± 28%, and the mean body mass index (BMI) was 27.2 ± 5.82 kg/m 2 . Patients in stage 4 were significantly younger (p Conclusions The ATS/ERS-GOLD staging system can be used to indicate differences in exercise capacity in patients with COPD stages 2 to 4 and to normalize apparent gender disparities. The value of differentiating stage 1 patients requires further studies with different outcomes.