Exercise capacity and ventilatory response during exercise in COPD patients with and without β blockade

Background: Although β blockade (BB) in patients with chronic obstructive pulmonary disease (COPD) does not show signs of worsening pulmonary function or respiratory symptoms, the effects on cardiopulmonary exercise testing (CPET) remain unclear. The aim of this study was to determine whether BB affects exercise capacity, gas exchange, and hemodynamic responses in patients with COPD. Methods: Twenty-four COPD subjects on BB were matched to 24 COPD subjects without BB according to age, gender, body mass index, and severity of COPD. All subjects underwent resting pulmonary function and symptom-limited CPET. Results: Comparing COPD patients with and without BB revealed that percent peak oxygen consumption and VE/VCO₂ nadir were not significantly different (45 ± 16 vs. 51 ± 23 %, p = 0.30, and 35.1 ± 8.5 vs. 36.2 ± 11.6 %, p = 0.69). Systolic blood pressure and heart rate at peak exercise were significantly decreased in COPD patients with BB (168 ± 16 vs. 185 ± 20 mmHg, and 109 ± 16 vs. 122 ± 14 bpm, respectively, p < 0.05). Conclusion: Exercise capacity and gas exchange remain unaffected in patients with COPD in the presence of BB, although heart rate and blood pressure are lower. These findings imply that BB does not adversely affect functional capacity in patients with COPD.