Figure 3. Bar graph representing mean (standard error of the mean) interleukin 13 (IL-13) serum levels between tertiles of wall area percentage (WA%) stratified by smoking status.
IL-13 serum levels increase significantly with increasing WA% tertile only in current smokers (p = 0.003). Former smokers do not exhibit a significant change in IL-13 levels with degree of airway thickening (FS = former smokers, CS = current smokers).