Modern Menopause Hormone Therapy Not Linked to Higher Heart Risk in 12-Year Study of 52,000 Women

For more than two decades, many women going through menopause have been told to fear hormone therapy because of its supposed risks to the heart. A large new study offers some reassurance for women who start today's treatments around the time of menopause.

Researchers in Israel followed more than 52,000 women for an average of 12 years and found that those who began modern menopause hormone therapy had rates of heart attack, stroke and related heart disease nearly identical to women who did not, the American Heart Association reported ^[1]. The findings were presented at the association's Scientific Sessions in Chicago, held Nov. 6-9 ^[1].

What the Study Found

The study drew on health records from Clalit Health Services in Israel and included 52,330 women ages 45 to 59 who had no history of heart disease, blood clots or cancer, according to the association ^[1]. About half started hormone therapy; the other half had a recent gynecology visit but did not start treatment ^[1]. The two groups were matched on age, body mass index, heart-risk factors, smoking and socioeconomic status ^[1].

Over follow-up that averaged 12 years and stretched as long as 23 years for some women, 4.4% of women on hormone therapy had a heart attack, stroke or related heart disease, compared with 4.6% of those who were not on it ^[1]. Death before age 80 occurred in 1.3% of the treated group and 1.2% of the untreated group, and the rate of blood clots was the same in both, about 0.33% ^[1].

Healio, a medical news service, reported that the adjusted hazard ratio for atherosclerotic cardiovascular disease was 0.98, meaning essentially no difference in risk ^[2]. The risk of blood clots and of death before 80 was also statistically unchanged ^[2].

The women in the study used pills, patches or gels ^[1]. The results did not differ by type or route, and oral formulations were just as safe as transdermal and gel versions, the lead researcher told Healio ^[2]. HealthDay reported that most women in the treated group used patches or pills ^[3].

Why It Matters

Hormone therapy has a complicated history. The heart association noted that earlier clinical trials produced mixed results and that they used higher-dose formulations that are no longer commonly prescribed ^[1]. The lead author, Ronen Arbel of Clalit Health Services and Sapir College in Israel, referred to the long shadow cast by the Women's Health Initiative, the major federal study that shaped how doctors viewed these treatments for years, Healio reported ^[2].

That shadow kept many women from treatments that can ease hot flashes, sleeplessness and other symptoms. Last November, the Food and Drug Administration removed the "black box" warnings from hormone replacement therapy products, according to the heart association ^[1]. The new study adds long-term data to that shift.

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"For many women, menopause symptoms can significantly affect their quality of life," said Dr. Stacey E. Rosen, a past volunteer president of the heart association who was not involved in the research ^[1]. She said the findings can help women and their doctors have better-informed conversations ^[1].

The Fine Print

The researchers were careful about what the study does and does not show. It was observational, so it cannot prove cause and effect, and unmeasured differences in exercise, diet, other health conditions or symptom severity could have played a role, the heart association noted ^[1]. Women were classified by the first type of hormone therapy they received, and later changes were not counted ^[1].

The findings were presented as a meeting abstract, which has not been peer-reviewed, and they should be considered preliminary until published in a full journal article ^[1][3].

Arbel also stressed that the results apply to the kind of women studied: those starting therapy in their mid-40s to late 50s without heart disease, prior blood clots or cancer ^[2]. They should not be extended to women who start long after menopause ^[2]. And the therapy is not a heart medicine. "HT should be prescribed to treat menopausal symptoms — not as cardiovascular prevention," Arbel told Healio ^[2].

He said the findings are consistent with the American College of Obstetricians and Gynecologists' guidance to begin hormone therapy within 10 years of menopause and before age 60 ^[1][2].

What Women Should Know

For women weighing their options, the message is a practical one. Menopause is a natural season of life, but its symptoms can be hard on marriages, work and sleep, and women deserve accurate information rather than outdated fear. The best step is a frank conversation with a trusted doctor about personal risks, family history and the benefits of treatment.

This study does not settle every question about hormone therapy. But for healthy women near menopause, it suggests that the heart risks many have worried about may be smaller than they were led to believe.