HRT - Golden Pill or Silver Bullet?31 Mar 2008

An article from our bi-monthly newsletter

Looking at the management of the menopause in general and hormone replacement therapy (HRT) over the last twenty years has been an illuminating experience and many lessons can be learned from it.

It is not so long ago since we used to read in the popular press of the "golden pill" and large observational studies demonstrated massive reductions in cardiovascular disease [1] and improvement in osteoporosis.

Or did they?

There is one big problem with observational trials and that is that there is no randomisation. This was classically the case with the trial quoted above and it did not take too long for people to ask the question, "Were the women taking HRT less liable to cardiovascular disease anyway?" Many people at the time said that the reduction in cardiovascular disease was so large that this explanation was not possible. But it was.

Disturbing noises started to come out from some very large, properly randomised prospective studies that HRT does not reduce cardiovascular disease [2]. Indeed initially there may even be a slight increase but, after five years, the position is largely a neutral one.

So why are women less likely to develop cardiovascular disease than men? Next question please! Similarly, the use of HRT to prevent osteoporosis has also been questioned.

Therefore, what is the current position regarding HRT? As regards risk, deep vein thrombosis, coronary heart disease, breast cancer and stroke are all slightly increased. Colorectal cancer and hip fractures are decreased. The overall mortality is not affected. So the advice with regard to cardiovascular disease prevention is [3]:

• HRT should not be initiated for the Secondary Prevention of Coronary Heart Disease.
• The decision to continue or stop HRT in women with Cardio-Vascular Disease who have been taking long-term HRT should be based on established non-coronary benefits and risks + patient preference.
• If a woman develops an acute cardio-vascular event or is immobilised whilst taking HRT, it should be discontinued or venous thrombo-embolism prophylaxis considered because of the increased embolic risk associated with immobilisation.
• Restarting of HRT should be based on established non-cardiac benefits and risk + patient preference.

The decision to recommend or not recommend HRT is now very much an individual one. There are no grounds for not recommending HRT. The overall position of HRT is therefore [4]:

• HRT provides relief from vaso-motor symptoms occurring at the time of the menopause.
• The risk/benefit balance of HRT in the treatment of these symptoms is favourable to most women.
• Women with a premature menopause may use HRT until age 50.
• The minimum effective dose and the shortest duration of HRT treatment should be used.
• HRT should not be recommended for the prevention of chronic disease.
• Women should be advised of the increased risk of stroke, deep vein thrombosis and gall bladder disease.
• Each decision to use HRT should be made on an individual basis with fully informed women.
• Treatment must be reviewed annually.

References:

1. Stampfer MK, Colditz GA et al (1991) Postmenopausal estrogen therapy and coronary heart disease: ten year follow up from the Nurses Health Study NEJM 325 756-762
2. Hulley S, Grady D et al (1998) Randomised trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group JAMA 280 605-613
3. Guidelines on secondary prevention of cardiovascular disease from American Heart Association from www.americanheart.org
4. Primary Care Training Centre (2008) Women's Health Management in Primary Care Distance Learning Pack Section 5 9