Postmenopausal changes in serum cytokine levels and hormone replacement therapy

Objective: Our purpose was to investigate the effect of hormone replacement therapy on the postmenopausal changes in serum cytokine levels. Study Design: Fifteen cytokines were measured by an enzyme-linked immunosorbent assay in 97 untreated and hormone replacement–treated women. Thirteen women were examined before and during hormone replacement therapy. Results: Serum concentrations of macrophage colony-stimulating factor were significantly (P< .05) lower during the early postmenopausal period (≤10 years) than the values in premenopause and the elevated levels in the late postmenopausal period (≤30 years). A significant increase in tumor necrosis factor α and a decline in transforming growth factor β1 were found in late postmenopausal women. Serum levels of macrophage colony-stimulating factor in women receiving hormone replacement therapy were significantly higher than those in untreated postmenopausal women. Furthermore, hormone replacement therapy induced a significant (P< .01) increase in serum levels of macrophage colony-stimulating factor, whereas serum levels of other cytokines were not affected. Conclusion: It is well documented that macrophage colony-stimulating factor lowers serum cholesterol concentrations and prevents atherosclerosis. Inducing the production of macrophage colony-stimulating factor is a possible additional mechanism of hormone replacement therapy in mediating the antiatherogenic effect. (Am J Obstet Gynecol 2001;184:309-14.)