Effect of smoking on the serum concentration of erythropoietin and granulocyte-colony stimulating factor.

Smoking is the most common cause of secondary polycythemia and may induce leukocytosis. We studied the relationship between hematopoietic growth factors and erythrocytosis and leukocytosis. Two sets of healthy male volunteers, consisting of 177 and 202 (age: 19-59 years) were each divided into four groups according to whether or not they smoked at least one package daily and their leukocyte count. Serum erythropoietin (Epo) concentration and granulocyte-colony stimulating factor (G-CSF) concentration were measured in the 177 and 202 volunteers, respectively. The mean serum Epo concentration was lower in smokers than in nonsmokers (p = 0.01 in the subjects without leukocytosis and p = 0.107 in those with leukocytosis, respectively). After 3 smokers stopped smoking, the Epo concentration increased 2 weeks later, and remained constant for 20 weeks. Smokers tended to have a higher mean serum G-CSF concentration than nonsmokers in the subjects without leukocytosis. Neither Epo nor G-CSF is the main etiology of smokers' polycythemia, and Epo production may be down-regulated by an elevated red-cell volume.