By Dr. Riya S. Chacko
Our understanding of women’s cardiovascular health has continued to evolve since the 1980s, thanks in part to large research studies such as the Women’s Health Initiative, UK Biobank and Framingham Heart Study. In addition to changing stereotypes about women and heart disease, such research has also changed how we assess women and their risk, leading to improved outcomes. Furthermore, we are becoming more aware of the cardiovascular effects of sex hormones and the relationship between cardiovascular risk factors and the onset of menopause.
What we know is that early menopause reduces a woman’s lifetime exposure to estrogen. Menopause is defined as the complete cessation of a woman’s menstrual period for one year. Early menopause is often defined as menopause before the age of 40. According to the American Heart Association (AHA), 10 percent of women in the U.S. experience menopause before the age of 45. Surgical menopause, as opposed to natural menopause, is defined as a bilateral oophorectomy (removal of the ovaries), which would be expected to affect a women’s sex hormone levels.
The Framingham Heart Study, started in 1948 in Framingham, Massachusetts, has followed 2,873 women. Kok, et al, published a study in 2006 based on the Framingham data that found the presence of cardiovascular risk factors (total cholesterol, weight gain, rise in systolic blood pressure, higher 10-year Framingham risk score) could predict the age of onset of menopause.
At the annual AHA Scientific Sessions in November 2019, researchers from Massachusetts General Hospital reported a study evaluating roughly 5,500 women who experienced natural menopause before the age of 40 and those with surgical menopause before the age of 40 based on the UK Biobank. They found that premature menopause increased the risk to develop cardiovascular risk factors such as diabetes, as well as cardiac conditions such as heart failure, coronary artery disease, atrial fibrillation, aortic calcification and stenosis, to name a few. They found this association regardless of whether women took postmenopausal hormone therapy and that the risk lasted for decades after menopause.
These findings have been supported in other studies such as the ARIC (Atherosclerosis Risk in Communities), which found those who achieved menopause before the age of 45 had a 20 percent higher risk of heart failure. Parikh, et al, reported in the Journal of American College of Cardiology in 2017 based on their analysis of the Framingham data that a woman’s duration of reproductive time (age of onset of first menstruation to menopause) predicted her risk of developing heart failure. Several studies so far suggest that early menopause has been linked to a higher risk of stroke, coronary artery disease, and heart failure.
The mechanisms for the association between the onset of menopause and cardiovascular risk are not well understood. What we do know is that estrogen positively affects the relaxation and expansion of blood vessels, affects cholesterol metabolism and insulin resistance to name a few. Progesterone as well has been shown to decrease blood pressure.
As a result of such research, the American College of Cardiology and American Heart Association now recommend in their 2019 updated guidelines for primary prevention of heart disease that women discuss their cardiovascular risk with their doctors if they have had premature menopause.
Although we still have much to learn about the unique risks to women and heart disease, one fact is clear — there is widespread recognition of the importance of this topic and increased global dedication to improving cardiovascular outcomes for all women. The conversation will continue.
By Dr. Riya S. Chacko, Cardiologist, is President of the Syracuse Board of Directors, American Heart Association.
