HRT increases stroke risk by a third, says study

HORMONE replacement therapy increases the risk of stroke by almost a third, a review of clinical trials revealed yesterday.

Concerns about the safety of long-term HRT use have grown in recent years after a series of studies linked it with a higher risk of breast cancer, heart attack and stroke.

While there were more than 450,000 prescriptions here for HRT in 2003, there were just 88,000 between January and May last year, according to figures from the General Medical Services Payments Board.

Researchers who reviewed the results of 28 trials involving almost 40,000 patients have concluded that HRT increased the risk of stroke by 29%.

The team, from the University of Nottingham, said patients with a high risk of stroke should stop HRT unless there is a strong medical reason not to.

The trials reviewed included a US study, involving almost 17,000 women over 50, which in 2002 linked HRT with higher risks of breast cancer, heart attack and stroke.

Britain’s Royal College of Obstetricians and Gynaecologists has also advised HRT should only be used in the short term to relieve menopausal symptoms. HRT has in some cases been prescribed to women to reduce the risk of osteoporosis - a measure which is now discouraged.

The latest review, published on bmj.com, found HRT was associated with a sharp increase in the risk of ischaemic stroke, caused by an insufficient blood supply to the brain. The severity of the stroke also increased with HRT use.

The researchers said: “A poor outcome after stroke, judged as combined death and dependency, was increased by half with hormone replacement therapy.

“We also found a non-significant increase in fatal stroke.”

The researchers said it was unclear why HRT should increase the risk of stroke and its severity when some studies suggested it might have a protective effect.

The review will raise further concerns among women seeking treatment for symptoms of the menopause, which can include hot flushes, insomnia, headaches and irritability.

The number of prescriptions for HRT has fallen as more trials have emerged highlighting possible dangers. But many experts say that in the short term the benefits can outweigh the risks because of improvements to quality of life.