Study links hormone therapy drugs to increased risk of heart conditions, blood clots

Drugs used in hormone therapy for postmenopausal women have been related with an increase in heart disease and blood clot risks, according to a study.

Hormone replacement therapy helps relieve postmenopausal symptoms such as hot flushes and night sweats by replacing hormones that a woman’s body is not producing enough.

Researchers, including those from Uppsala University in Sweden, said that certain tablets containing both oestrogen and progestogen are associated with a higher risk of heart disease and rare, but serious blood clots, known as venous thromboembolism.

However, tibolone—another hormone therapy—was associated with an increased risk of cardiovascular conditions, including heart attack and stroke, but not blood clots. These drugs are available in India.

The findings, published in The British Medical Journal, highlighted “the diverse effects of different hormone combinations and administration methods on the risk of cardiovascular disease”.

The researchers said that while previous studies have suggested a link between hormone therapy and an increased risk of cardiovascular disease, information on specific risks linked to different types of therapy is unclear.

For their analysis, the authors looked at 138 previously published studies, involving nearly 9.2 lakh women in Sweden aged 50-58 years between 2007 and 2020, who had not used hormone therapy in the previous two years.

Tibolone and oestrogen-progestogen tablets were two of the eight types of hormone replacement therapies that the women were prescribed. National registry data were used to track cardiovascular events over two years, along with other aspects such as high blood pressure and diabetes.

Over the follow-up period of two years, nearly 24,100 cardiovascular events were recorded among the 9,19,614 women studied.

Taking tablets containing both oestrogen and progestogen or tibolone was associated with an increased risk of ischaemic heart disease, in which blood supply to heart is reduced because of a narrowing of vessels.

This translates to about 11 new cases of ischaemic heart disease per 1,000 women who start treatment with oral combined continuous therapy (taking oestrogen-progestogen tablets) or tibolone over one year, the researchers said.

An increased risk of blood clots was also found for oral combined continuous therapy.

“If 1,000 women started each of these treatments and were observed for a year, we would expect to see seven new cases of venous thromboembolism across all groups,” the authors wrote.