Comment from Professor Helena Teede

Following confirmatory studies, women have again been advised not to start hormone therapy in their older age, many years beyond menopause. Another large study to report on hormone therapy use in older women, the WISDOM study published 12 July, 2007, has confirmed that combined oestrogen and progestin results in a small increase in the risk of heart attacks and blood clots.¹

This is now the 10th large study to confirm that if hormone therapy is started in older women aiming for prevention of disease, the risks outweigh the benefits.

This information is not relevant for the majority of women considering hormone therapy or taking hormone therapy at the time of menopause for symptom relief.
 
As based on extensive evidence, women at menopause can take low-dose hormone therapy short-term without a significant increase in risk and with substantial benefit in symptom relief and quality of life.

Note: Hormone therapy (HT) is also known as hormone replacement therapy (HRT) 

Background

Results from the Women’s International Study of long Duration Oestrogen after Menopause (WISDOM) were published on 12 July, 2007 in the British Medical Journal. The study was a multi-centre randomised controlled trial of hormone replacement therapy (HT) in postmenopausal women conducted in Australia, New Zealand and the UK.  

In 2002, the Women’s Health Initiative (WHI) trial found that postmenopausal women taking HT had more heart attacks and strokes than non-HT users. The trial was halted early and millions of women around the world stopped taking HT. But scientists now believe that these risks may only apply to older women who do not normally use HT.

In 1999, the WISDOM trial began to assess the long-term risks and benefits of HT after the menopause. This trial was also stopped after the first WHI results appeared, but the WISDOM findings, published on 12 July, 2007, make an important contribution to the body of knowledge about HT when it is initiated in older, postmenopausal women.

The WISDOM team identified 5,692 healthy women registered at general practices in the UK, Australia and New Zealand with an average age of 63 years and 15 years after menopause.

The women who had not had a hysterectomy were split at random into two groups. One group was given a daily dose of combined hormone therapy (oestrogen and progestogen) and the other group was given a placebo pill. Women who had had a hysterectomy were split between combined hormone treatment, oestrogen only and a placebo.

All women were monitored for an average of 12 months and main outcomes such as cardiovascular disease, osteoporotic fractures, breast cancer and deaths, were recorded.

The study confirms an early increase in thromboembolic and cardiovascular risk in older women starting hormone replacement therapy many years after menopause. The results are also consistent with the early findings of WHI and other trials, and support the conclusion that combined oestrogen and progestogen therapy should not be initiated to prevent cardiovascular disease in older, postmenopausal women.

However, the authors, including Professor Alastair MacLennan, Department of Obstetrics and Gynaecology, University of Adelaide, Women’s and Children’s Hospital, Adelaide, stress that these results cannot necessarily be applied to younger menopausal women starting hormone replacement therapy to relieve symptoms such as hot flushes and night sweats. For these women, recent studies suggest there may be cardiovascular benefits of taking HT around the time of menopause. The authors say that more research is needed to assess conclusively the long-term benefits and risks among these women. 

More information about the Women's Health Initiative and Million Women Study

Find out about the Women's Health Initiative (WHI) and Million Women Study (MWS) along with expert comment from the Jean Hailes Foundation for Women's Health at
Women's Health Initiative 
The Million Women Study

Reference

1. Vickers MR, MacLennan AH, Lawton B, Ford D, Martin J, Meredith SK, et al. Main morbidities recorded in the women’s international study of long duration oestrogen after menopause (WISDOM): a randomised controlled trial of hormone replacement therapy in postmenopausal women. BMJ 2007 doi: 10.1136/bmj.39266.425069.AD.

Content update November 27, 2008