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 (<less than or equal to>10 years) than the values in premenopause and the elevated levels in the late postmenopausal period (less than or equal to 30 years). A significant increase in tumor necrosis factor a and a decline in transforming growth factor pi 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.