Effect of hormone replacement therapy on hemostatic variables in post-menopausal women

OBJECTIVE: Hormone replacement therapy (HRT) has been increasingly promoted over the last 40 years to improve quality of life, and to reduce the risks of osteoporotic fractures and coronary heart disease (CHD). Recent randomized controlled clinical trials reported that HRT usage is associated with an increased risk of myocardial infarction (MI), stroke, and venous thrombosis. We conducted this study to evaluate the mean levels of some hemostatic parameters among groups that differ in estrogen levels and age.

METHODS: We studied 150 healthy women in an observational comparative study, divided into 3 groups. Forty women were post-menopausal using HRT for a period of 6 months to 17 years. Fifty-five women were post-menopausal and were not using HRT. Fifty-five women were younger pre-menopausal women with an age range of 20-54 years. The HRT group women were recruited from gynecologist private clinics while the other 2 groups were recruited in a random way from the society in Damascus, Syria between August 2002 and January 2003. We determined estradiol, fibrinogen, antithrombin III (AT III) and protein C in all women.

RESULTS: When compared with post-menopausal non-users group, current HRT users had higher mean levels of estradiol, but lower mean levels of AT III and protein C, and similar mean levels of fibrinogen. When compared with pre-menopausal group, current users had similar mean levels of estradiol, AT III and protein C, but higher mean levels of fibrinogen. However, post-menopausal non-users women had higher mean levels of fibrinogen and lower mean levels of AT III and protein C when compared with pre-menopausal women.

CONCLUSION: Hormone replacement therapy treatment did not change fibrinogen mean levels, but it caused a decrease in AT III and protein C mean levels.