Characteristics of study individuals (n=92) for lung mRNA analysis by real-time PCR

CharacteristicsNever smokers (n=18)Smokers without COPD (n=26)COPD GOLD II (n=34)COPD GOLD III–IV (n=14)
Sex male/female6/12#19/7#31/3#8/6#
Age years65 (56–70)63 (55–70)66 (58–69)§56 (54–60),+,§
Smoking status
 Current smokerna16220
Smoking pack-yearsna28 (15–45)45 (40–60),§30 (25–30),+,§
DLCO mmol·min−1·kPa−121.5823.3017.222.9,+,§
% predicted DLCO90.0080.0067.0035.00,+,§
DLCO/VA mmol·min−1·kPa−1·VA−14.643.893.510.87,+,§
% predicted DLCO/VA102.8591.0087.0058.50,+,§
% predicted FEV1102.0095.0068.00,§25.50,+,§
FEV1/FVC %78.0075.0056.00,§32.00,+,§

Data are presented as n, n/n or median (IQR). COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; na: not applicable; DLCO: diffusing capacity of the lung for carbon monoxide; VA: alveolar volume; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; IQR: interquartile range. #: p<0.001 (by Fisher's exact test); : p<0.05 versus never smokers (by Mann–Whitney U-test); +: p<0.05 versus COPD GOLD II (by Mann–Whitney U-test); §: p<0.05 versus smokers without COPD (by Mann–Whitney U-test).