NOS3 and chronic obstructive pulmonary disease: COPD-chronic obstructive pulmonary disease, FEV1-forced expiratory volume in 1 second, p-p value, OR-odds ratio, CI-confidence interval, N-number of subjects, eNOS-endothelial nitric oxide synthase, ACE-angiotensine converting enzyme.<br>acrude, badjusted for smoking status and sex.