Stacey Missmer

Women with endometriosis, especially those 40 years old or younger, may have a higher risk of heart disease, according to new BWH research published in Circulation: Cardiovascular Quality and Outcomes, an American Heart Association journal.

The study examines the link between coronary heart disease—which occurs when plaque builds up inside the coronary arteries and causes damage in the heart’s major blood vessels—and endometriosis, a disorder in which tissue that normally lines the uterus grows outside of the uterus. Researchers reviewed the records of 116,430 women enrolled in the Nurses’ Health Study II. Endometriosis was diagnosed using surgical examinations in 11,903 women.

During 20 years of follow-up with participants, researchers found that compared to women without endometriosis, women with the condition were:

• 1.35 times more likely to need surgery or stenting to open blocked arteries,
• 1.52 times more likely to have a heart attack and
• 1.91 times more likely to develop angina, or chest pain

Moreover, women age 40 or younger with endometriosis were three times more likely to develop heart attack, chest pain or need treatment for blocked arteries, compared to women without endometriosis in the same age group.

“Women with endometriosis should be aware that they may be at higher risk for heart disease compared to women without endometriosis, and this increased risk may be highest when they are young,” said Fan Mu, ScD, the study’s lead author, who was a research assistant at BWH when the study was conducted.

Researchers noted that surgical treatment of endometriosis—removal of the uterus or ovaries—may partly account for the increased risk of heart disease. Surgically induced menopause prior to natural menopause may increase the risk of heart disease, and this elevated risk may be more evident at younger ages.

An estimated 6 to 10 percent of women of reproductive age have endometriosis, but exact numbers are unknown since it cannot be diagnosed without surgery. Many girls and women do not realize that distressing menstrual cramps and pelvic pain can be due to endometriosis.

“It is important for women with endometriosis to adopt heart-healthy lifestyle habits, be screened by their doctors for heart disease and be familiar with symptoms because heart disease remains the primary cause of death in women,” said senior study author Stacey Missmer, ScD, director of Epidemiologic Research in Reproductive Medicine at BWH and scientific director of the Boston Center for Endometriosis.

BWH’s Janet Rich-Edwards, ScD, MPH, director of Developmental Epidemiology at the Connors Center for Women’s Health and Gender Biology, epidemiologist Eric Rimm, ScD, and biostatistician Donna Spiegelman, ScD, were also co-authors of this study.