Smoking, leukocyte count, and ventilatory lung function in working men.

Results of a cross-sectional study of ventilatory lung function (VLF) in a group of 307 working men showed that the leukocyte count in peripheral blood is more closely associated with the relative position (percentile) of a person in the frequency distribution of VLF than is smoking intensity. Leukocyte count is significantly (and inversely) correlated with VLF in nonsmokers as well as in smokers. A multiple regression analysis indicated that, after accounting for the effect of height and age, white blood cell (WBC) count explains more of the VLF variance than many other health determinants. Moreover, WBC count is the only variable, apart from height and age, that contributes significantly to the regression. Current smokers with elevated leukocyte count in peripheral blood may constitute a defined high-risk group because they demonstrate more negative regression age coefficients when compared with smokers without elevated WBC or with nonsmokers. Mechanisms that may explain these findings are discussed.