Parameters COPD Non-COPD
 Age 66 ± 2.77 65 ± 3.39
GENDER male/female 65%/35% 52.5%/47.5%
Smoking/Non-Smoking 67.5%/32.5% 75%/25%
Alcohol/Non-alcoholic 74%/26% 83%/17%
Table 1: Numerical data are expressed as mean value with standard deviation; frequencies as number and percentage of study subjects with certain variable.