It can feel like we will never know the answer to this question.
I’d be remiss to let February, American Heart Month, slip by without discussing heart disease in women. You may see this symbolized by a red dress or the color red in some form, as a “symbol of solidarity”.
The fact is most of us will die of heart disease and this leads to death in 1 of 3 women in America each year.
Interestingly, there’s a palpable fear of breast cancer and cancer in general throughout the population. I could certainly include myself in that at times. My thoughts on the reasons for that will have to be the subject of a future post.
But just for some perspective, heart disease kills more women than all types of cancer combined.
In the obstetric part of my world, heart disease has come to light more recently because of growing evidence that pregnancy complications can increase risk of heart disease. This was initially an increased risk in the postpartum period and up to 7 years after pregnancy. Now evidence is showing that the risk persists later in life, increasing cardiovascular disease and stroke in women aged 65 and older.
So, What is heart disease?
Heart disease is the layman’s term for cardiovascular disease, which includes things like ischemic heart disease (blocked blood flow in the heart, or heart attack) as well as stroke.
What happens to our risk with menopause?
Age is a factor in increasing risk of heart disease. It seems that the menopausal transition is separately a factor for women - double whammy.
Menopause (and loss of estrogen) leads to an increase in LDL cholesterol and triglycerides, insulin resistance, overall weight and how body weight is distributed.
Body weight distribution changes lead to more fat deposited around the organs and abdomen (visceral fat) as opposed to our fat under the skin (subcutaneous fat).
These are known risk factors for heart disease.
Does estrogen help us or hurt us?
There has been so much controversy over this for decades.
I’ve referenced the Women’s Health Initiative study in some of my Instagram and other posts, which is the study from 2002 that sent hormone replacement therapy down the toilet for many women. Most of that was due to an increased risk of breast cancer found in one hormone group (but not the other, which had a decreased risk actually) though there was no increase in death from breast cancer. That study also found an increase in heart attack in a hormone group.
Subsequent studies looked deeper past the flaws of that study, often referred to as “WHI”, since WHI patients were up to age 79 and the smallest portion in the study were women ages 50-54. This is the age group most likely to seek hormone replacement therapy in the first place because this is when most are symptomatic (hot flashes, night sweats, brain fog, etc).
With more investigation, it seems there is a timing window of when hormone replacement therapy should be given and offers benefit.
A study called KEEPS looked at women ages 48-52. They measured artery calcification as well as arterial wall thickness, physical findings of heart disease. In the hormone group there was no acceleration of these processes.
A small study in Denmark published in 2012 randomized women to receive hormone replacement therapy or not and followed them for ten years. The average age at randomization was 50 and they had been in menopause for seven months, again testing the hypothesis that early hormone replacement therapy confers benefit. The hormone group had a significantly decreased risk of death, heart attack, and heart failure without any increased risk of cancer, including breast.
Whoa.
How can that be?
I’ve been down a rabbit hole (should I call it a mouse hole?) reading about the effects of estrogen on the hearts of mice. It really brings me back to studying cellular biology in college. We have different estrogen receptors (so do mice) scattered throughout our body. Overall this is why menopause symptoms affect more than just our temperature. We have estrogen receptors in our joints, our brains, and you guessed it, our hearts.
When estrogen binds to its receptor on the mitochondrial membrane (a very important work horse inside each of our cells), the mitochondria initiate a series of cellular changes that ultimately can be protective of the heart.
Estrogen also has action against the hardening effect of heart disease, or fibrosis. One study even found that fibrosis could be reversed in male mice who were given estrogen.
Also in male mice, giving estrogen restored the function of Vascular Endothelial Growth Factor (VEGF) that leads to new blood vessel growth and ultimately positive heart health.
Estrogen also affects the blood vessels by helping the lining, or the endothelium. When the lining is not healthy, it leads to inflammation, blood vessel constriction, and increased clotting. Estrogen can be a helpful factor in this process.
What’s my take?
My take is that hormone replacement therapy (estrogen included) is net positive for women early in their menopausal season who are otherwise candidates (a patient already with heart disease would not be a candidate).
Resources:
Some of the information contained in this article is the result of my training, medical knowledge, and personal experience without a specific source to be cited.
This is not medical advice.
https://www.goredforwomen.org/en/about-heart-disease-in-women/facts
https://bmjopen.bmj.com/content/bmjopen/6/1/e009880.full.pdf
https://pubmed.ncbi.nlm.nih.gov/23048011/
https://link.springer.com/article/10.1186/s13293-017-0152-8
