When it Comes to MHT and Heart Disease Risk, Your Arteries’ Age, Not the Candles on Your Cake Matter

Determining your cardiovascular health is key, study shows.By Selene Yeager
If and/or when to start menopausal hormone therapy (MHT) is a subject of ongoing research and debate. That’s especially true in the realm of heart disease where cardiologists have traditionally been more averse to hormone therapy because of worries of increased risk for cardiovascular disease following the Women’s Health Initiative research of the early 2000s.

More recent research has begun changing that perception. Now it’s become clear that when it comes to heart disease risk, timing matters. For instance, a 2015 meta-analysis reported that starting hormone therapy within the first 10 years of menopause reduced the risk of heart disease death by 48 percent. Another meta-analysis found that current users of hormone therapy had a 28 percent lower risk of heart disease.

In 2016, the International Menopause Society stated that hormone therapy can reduce the risk of diabetes and has positive effects on vascular function, cholesterol levels, and blood sugar metabolism, all of which are risk factors for heart disease.

Most recently, 2020 Menopausal Hormone Therapy Guidelines concluded that for women starting therapy within 10 years of reaching menopause the trend is toward a reduction in heart disease risk, but for women starting therapy more than 20 years after menopause, risk increases.

Why Timing Matters
I, like you probably are, was a little perplexed as to why timing seemed so critical here. So I asked Dr. Avrum Bluming, who is a hematologist as well as an oncologist, during my interview with him and Carol Tavris, Ph.D., during the Hit Play Not Pause episode Estrogen Matters, and it became much clearer.

“As we age, we all develop some level of atherosclerosis. Our blood vessels narrow and estrogen is like the glue that can cause platelets—small corks that circulate in the blood—to clump,” Bluming says. “When these clumped platelets enter an already narrowed blood vessel, it can cause a block and induce a heart attack or a stroke.”

This is also why estrogen can be protective when used earlier, he says. “Estrogen started relatively early, within that 10-year framework, prevents the blood vessels from narrowing and preserves the blood vessels’ ability to expand when necessary.”

Similarly, research shows that there’s no increased risk of stroke in women younger than 60 or who are fewer than 10 years from the start of menopause. MHT increases the risk of stroke in women older than 60, because of the risk for clotting.

Vascular Age Is Not Necessarily Your Birthday Age
There’s only one rub for active, healthy women: our chronological age does not necessarily match up with our vascular age. That is, we may benefit from MHT without the increased risk later in our menopause journey because our arteries are still clear and compliant.

A recent study published in the journal Menopause shows that a woman’s “vascular age” is a better indicator of cardiovascular disease risk than her chronological age or years since menopause.

To reach this conclusion, researchers from the University of Oklahoma College of Medicine studied data from the above-mentioned Women’s Health Initiative, which included 27,347 postmenopausal women ages 50 to 79 who were enrolled from 1993 to 1998 across the United States; some received hormone therapy and some received a placebo. An enormous amount of data about the women’s overall health had been gathered when they enrolled in the WHI and over the 18 years, the study continued. In this particular study, the Oklahoman researchers dug into the data on the women who ended up with cardiovascular disease.

To examine that data, they used two different cardiovascular risk scoring systems. One from the American Heart Association and American College of Cardiology, and the other was the Framingham Risk Score, both of which assess factors like age, race, total cholesterol, HDL cholesterol, blood pressure, use of blood pressure medication, diabetes and smoking status.

In the end, they found that both cardiovascular risk scoring systems were a better predictor of cardiovascular disease than chronological age and years since menopause.

“What this study tells us is that we have to look at the true risk of cardiovascular disease independent of age,” study author Robert Wild, M.D., Ph.D., MPH, a physician-scientist at the University of Oklahoma College of Medicine said in a press release.

“Age certainly plays a role, but it is modified by other risk factors. We have to make individualized decisions instead of using a broad brushstroke,” Wild said in the release. “It’s important for our management of patients because it allows us to begin to quantify risk and refine it above and beyond a simple age estimate.”

Your doctor can help you determine your own vascular age. There are also some online tools, such as My Health Checkup that can give you an idea of where you stand based off of a 5-minute survey including your lifestyle, blood pressure, blood lipid levels, and other heart health factors. (Of course, this does not replace your personal physician).

One final note: MHT is known to increase the risk of venous blood clots called thrombophlebitis. If you’re at an increased risk for blood clotting and interested in hormone therapy, talk to your doctor about transdermal hormone applications. Transdermal MHT does not increase the risk of blood clots. That’s because the liver increases the production of blood clotting factors when it processes estrogen. Transdermal hormone applications bypass the liver and go directly into the bloodstream.