Hormone replacement therapy not recommended for stroke prevention
Hormone replacement therapy (HRT) cannot be recommended for the primary or secondary prevention of stroke, a meta-analysis suggests.
Researchers reviewed 28 randomised controlled trials and concluded that
HRT is associated with an increased risk of stroke, in particular ischaemic
stroke.
They report that out of the 39,769 patients included in the review 2.7
per cent taking HRT experienced a stroke compared with 2.0 per cent in
the control group. They estimate that one person in every 147 people
treated with HRT would experience a stroke (number needed to harm).
Overall, HRT use was associated with a 29 per cent increased risk of
stroke. The
researchers also report that among patients who had a stroke, those taking
HRT had a
56 per cent higher frequency of death or
incapacity.
The authors acknowledge that there is clinical variation in the studies
included. For example, they say that the dose of oestrogen used in some
studies may be higher than the usual starting dose in Britain and that
several of the trials may have been too short to show a beneficial effect
on stroke risk.
Nevertheless, they say that extrapolation of these data would suggest
that women at a high risk of stroke, such as those who have had a previous
stroke, have coronary heart disease or with multiple vascular risk factors,
should stop taking HRT unless there is a strong contrary medical reason
(published online in BMJ Online First, 7 January 2005).
However, the study has been criticised by the charity Women’s Health
Concern, which says that the analysis is dominated by findings from the
Women’s Health Initiative studies, which, it says, are the only
studies that individually show a small but significant increase in stroke
with HRT use.
The charity points out that two important risk factors for stroke when
on HRT are the age of the user and the dose of oestrogen used and says
that this review does not address these issues and so provides no new
information.
“
Women needing to start HRT should not be frightened off by this new publication,
nor should those already taking it for any valid reason be discouraged,” it
advises. |