Table 1—

Clinical characteristics of chronic obstructive pulmonary disease patients with and without chronic bronchitis(CB)

With CBWithout CBp-value
Subjects n5360
Age yrs61±862±70.28
Current smoker yes/no40/1331/290.009*
Pack-yrs42 (34–56)40 (28–53)0.12
Post-bronchodilator FEV1# L2.01±0.42.04±0.50.49
Post-bronchodilator FEV1 % pred63±863±100.54
Post-bronchodilator FEV1/IVC %49±847±90.34
Reversibility FEV1 % pred6.8±56.9±50.92
PC20 methacholine mg·mL−10.59 (0.15–2.72)0.61 (0.17–2.07)0.89
RV/TLC %48.6±1047.8±70.61
TL,CO/VA % pred73.8±2577.2±260.49
  • Data are presented as mean±sd or median (interquartile range (IQR)), unless otherwise stated. BMI: body mass index; FEV1: forced expiratory volume in one second; % pred: % predicted; IVC: inspiratory vital capacity; PC20: provocative concentration causing a 20% fall in FEV1; RV: residual volume; TLC: total lung capacity; TL,CO: transfer factor of the lung for carbon monoxide; VA: alveolar volume. #: adjusted for length; : geometric mean (IQR). *: p<0.05.