For many older women, menopausal symptoms such as hot flashes, dry mucosa, and insomnia can be treated effectively with hormone therapy. But prescriptions have dropped over the past 15 years as research has shown a link between such therapy and an increased risk of certain diseases, including stroke.
Now a new Swedish study, published in the journal PLOS Medicine, shows that postmenopausal hormone therapy is not associated with increased risk of stroke as long as it is started early.
“New research shows us that hormone therapy actually has a positive effect on blood vessels if initiated early on in the menopause, but not if initiated late,” said Dr. Karin Leander, researcher at Karolinska Institute of Environmental Medicine.
“So there was reason to re-examine whether hormone therapy is linked to the risk of stroke, taking, of course, the time of administering into consideration.”
For the research, Leander and her colleagues analyzed data on postmenopausal hormone therapy from five Swedish cohort studies involving a total of 88,914 women, combined with data from national registries on diagnoses and causes of death during a follow-up period.
Their findings reveal that hormone therapy was not linked to increased risk of stroke (ischemic and haemorrhagic stroke combined) if the therapy was initiated within five years of menopausal onset.
Means of administration (oral, via the skin or vaginal), type of therapy (combination or oestrogen only), active substance and treatment duration did not appear to affect stroke risk. In sub-analyses, however, there was a notable increase in risk for haemorrhagic stroke (the less common form) if the therapy contained the active substance conjugated equine oestrogens.
Drugs containing oestradiol, on the other hand, did not appear to increase risk. A higher risk was also seen for both ischemic and haemorrhagic stroke if the therapy was started later than five years after the onset of menopause and contained conjugated equine oestrogens.
“The risk of stroke seems virtually eradicable if treatment commences early, but it’s naturally important to take account of the increase in risk that exists under certain circumstances,” said Leander. “These results provide doctors with a better scientific base on which to take decisions on treatment for menopausal symptoms.”
Menopause typically begins between the ages of 45 and 55, with 51 being the average age of onset in the United States. About three in ten women in the menopause transition are afflicted by severe symptoms such as hot flashes, insomnia, fatigue, and/or night sweats.
Source: Karolinska Institutet