Hormone therapy risky after menopause

Hormone replacement therapy (HRT) in women many years after menopause increases the risk of heart attacks and blood clots. Previous studies have showed elevated risks of breast cancer, heart attack, blood clots and stroke in postmenopausal HRT users compared with non-users. Researchers from the University of Adelaide in Australia studied 5,692 women aged between 50 and 69 years of age participating in the women's international study of long duration oestrogen after menopause (WISDOM). The women were randomly selected to receive oestrogen-only HRT, oestrogen plus progesterone HRT or placebo. The average period from menopause to HRT initiation was 15 years. Although ten years of treatment was planned, the study was stopped early after a median follow-up period of 11.9 months. Compared with placebo, use of combination HRT was associated with significantly increased risks of major cardiovascular events (7 versus 0 events) and blood clots (22 versus 3 events). No significant differences in outcomes were noted between combination and oestrogen-only HRT. By contrast, HRT use did not affect the risks of cancer, stroke, fractures or death. The findings indicate that hormone replacement therapy increases the risk of heart attack and blood clots when started many years after menopause. The results are consistent with the findings of the women's health initiative study and secondary prevention studies. However, further research is needed to assess the long-term risks and benefits of starting HRT near the menopause, when the effect may be different.