Multivariate analysis of each of the measured cytokines in the study group, using smokers without emphysema as a putative control group.

*Statistically significant; b =  regression coefficient.
Analysis adjusted for sex (EGF, MIP-1beta), age (VEGF) and smoking status (TGF-alfa) because these factors were statistically significant in the univariate analysis.
Cytokines levels were log transformed for the analysis.