In a Danish study, women treated with long-term hormone replacement therapy soon after menopause had significantly reduced risk for mortality, heart failure and myocardial infarction, and no increase in risk for cancer, venous thromboembolism or stroke.
HRT therapy has been subject to much discussion due to both positive effects (reduced risk of cardiovascular disease) and negative effects (increased risk of breast cancer). Conflicting results have led clinicians to believe that time from the start of menopause until initiation of HRT can account for differences in cardiovascular outcome.
Danish researchers carried out a randomized trial to establish whether HRT can reduce cardiovascular risk if started early after menopause. The trial included 1,006 women (504 receiving HRT and 502 in a non-HRT group). All were white, healthy, recently menopausal and ages 45 to 58. Women who had undergone a hysterectomy were included only if they were age 45 to 52. Exclusion criteria included a history of bone disease, previous or current cancer, current or previous use of HRT within the past three months and alcohol or drug addiction.
All data on diagnoses or death were taken from the Danish Civil Registration System and National Hospital Discharge Register. The primary endpoint was death or hospitalization for a myocardial infarction or heart failure.
After 10 years of randomized treatment, the women were encouraged to discontinue the use of HRT due to results from the Womens Health Initiative and the Million Women Study. During this period, 26 women in the non-HRT group died and 33 died or experienced a cardiovascular endpoint, compared with 15 deaths and 16 deaths or cardiovascular endpoints in the HRT group.
The women were followed for another six years. During this time, the primary endpoint was seen in 53 women in the non-HRT group (40 deaths, eight cases of heart failure and five cases of MI) and 33 women in the HRT group (27 deaths, three cases of heart failure and three cases of MI). Causes of death were 23 cardiovascular deaths and 17 non-cardiovascular deaths in the non-HRT group and six cardiovascular deaths and 21 non-cardiovascular deaths in the HRT group.
The study also found that women who had undergone a hysterectomy and younger women taking HRT had a significantly reduced risk of death or breast cancer.
The study appeared Oct. 10 on the website of the British Medical Journal and is available at www.bmj.com/content/345/bmj.e6409.