Table 1 Patient characteristics
CharacteristicCOPD patients (n = 2)Healthy controls (n = 40)p Value
Age (y)73.0 (8.0)70.9 (9.3)0.32
Sex (male:female)77:519:21<0.01
Smoking status (current:former:never)10:72:01:17:22<0.01
No of cigarette packs*year65.3 (37.8)11.2 (15.9)<0.01
BMI (kg/m2)21.5 (3.0)24.1 (3.5)<0.01
FEV1 (l)1.5 (0.6)2.2 (0.7)<0.01
%FEV1 (% pred)56.9 (20.4)101.3 (15.9)<0.01
RV/TLC (%)43.6 (7.7)ND
Dlco/Va (ml/min/mmHg/l)2.7 (1.0)ND
Pao2 (kPa)8.3 (0.9)ND
Paco2 (kPa)4.6 (0.5)ND
  • Gender and smoking status were evaluated by the χ2 test. The number of cigarette packs*year was evaluated by the Mann–Whitney U test. All other indices were evaluated by the unpaired t test.

  • BMI, body mass index; COPD, chronic obstructive pulmonary disease; Dlco, diffusing capacity of the lung for carbon monoxide; FEV1, forced expiratory volume in 1 s; ND, not done; Paco2, partial pressure of arterial carbon dioxide; Pao2, partial pressure of oxygen in arterial blood; RV, residual volume; TLC, total lung capacity; Va, alveolar volume.