The Womens Health Initiative (WHI) study conducted five years ago led many menopausal women to abandon hormone therapy because of the suggestion that the drug increased the risk of blood clots, heart attacks and breast cancer. The trials of the WHI were stopped early because of increased health risks and the failure to prevent heart disease. The pills contain either estrogen alone or a combination of estrogen-progestin.
Secondary analyses of findings from the study suggest that women who begin hormone therapy within 10 years of menopause may have less risk of coronary heart disease (CHD) due to hormone therapy than women farther from menopause.
Although the findings did not meet statistical significance, they suggest that the health consequences of hormone therapy may vary by time from menopause. In particluar, women in their 50s have a lower risk of experiencing these side effects than older women.
The analyses also suggest that the increased risk in heart disease due to hormone therapy in older women is primarily in those who also have hot flashes and night sweats. Study participants who had these symptoms were more likely to have risk factors for CHD such as high blood pressure or high blood cholesterol, but it was not clear whether this explained their higher risk on hormone therapy.
The analysis, however, did confirm that hormone therapy increases the risk of stroke and this risk does not appear to be influenced by age or time since menopause. Furthermore, even in women within 10 years of menopause, there appears to be an increased risk of breast cancer in women taking estrogen with a progestin.