Women who use hormone replacement therapy, or HRT, to relieve symptoms of menopause are at increased risk of stroke, according to a review of 28 HRT trials.
Researchers at Nottingham University in England, who looked at the findings of trials involving nearly 40,000 women, said HRT was associated with an overall 29 percent raised possibility of stroke.
The results support previous studies that have suggested a link.
“Hormone replacement therapy was associated with an increased risk of stroke,” said Philip Bath, a professor at the university.
“This systematic review supports the results of individual trials and previous reviews finding that hormone replacement therapy does not reduce the risk of stroke in postmenopausal women,” he added.
HRT was associated with a raised risk of ischaemic stroke, which is caused by an insufficient blood supply to the brain.
The report, published online by the British Medical Journal, found that women who were taking the drug and suffered a stroke seemed to have a worse outcome.
Severity of stroke also increased
“The severity of stroke was increased with hormone replacement therapy,” Bath added.
The researchers do not know why the drugs used in the trials, in which women were treated with estrogen-only therapy or combined estrogen and progestogen therapy, raised the risk of stroke.
Last year the National Institutes of Health in the United States stopped a trial of women taking estrogen replacement therapy after they discovered the pills increased the stroke possibility.
Swedish researchers also halted a study examining the impact of HRT in women with a history of breast cancer because of an unacceptably high risk of recurrence of the disease.
Millions of women have used HRT to relieve hot flushes, mood swings and sexual problems linked to the menopause and to stave off osteoporosis, or brittle bone disease.
The Swedish decision followed moves by American and British scientists who also stopped trials after learning HRT may increase the risk of breast cancer, stroke and blood clots.
