Association between hormonal therapy and stroke in menopausal women

This trial aimed to identify whether there was an association between how hormonal therapy and the incidence of stroke in women. The authors concluded that oral estrogens as well as norpregnane derivatives had a higher risk of stroke, while transdermal estrogens and other progestogens did not.

Women going through menopause can be treated with hormonal therapy that will relieve symptoms and also decrease the risk of bone loss that can occur during menopause. This hormone therapy (HT) generally includes treatment with hormones estrogen and progesterone. Studies have shown, however, that there can be a higher risk of venous thromboembolism (VTE – blood clot in the veins) and stroke associated with HT treatment. While guidelines indicate using transdermal estrogens (patch on the skin) rather than oral estrogens to decrease the risk of VTE, there is little known about the safest treatment to reduce the risk of stroke.

The authors combined data from 15,302 women in total, between the ages of 51-62 Group 1 consisted of 3,144 women who had been hospitalized from a stroke, while group 2 included 12,158 healthy women.

The rate of HT use was similar, with approximately 7% of women in each group on some form of HT treatment.

The risk of stroke associated with oral estrogens was 58% higher compared to non-users. This risk increased as the dose of oral estrogen increased. There was no significant difference in the risk of stroke between transdermal estrogen users and non-users.

The type of progestogen also had an effect on the risk of stroke. There was no difference in risk with progesterone, pregnanes or nortestosterones, however norpregnane derivatives were associated with over double the risk of stroke compared to non-users.

Age and cardiovascular risk factors did not affect the association of transdermal or oral estrogens with risk of stroke.

The authors concluded that the route of estrogens as well as the type of progestogens given in hormone therapy had an effect on the risk of stroke in menopausal women. They suggested that transdermal estrogens were the safest route and to avoid norpregnane derivatives.

These conclusions were made from data extracted from a database, rather than a controlled clinical trial. 

Speak to your doctor about the possibility of changing to transdermal estrogens.