Why, you might ask, should there be a symposium on heart disease in women? When we talk about pregnancy-related issues, uterine fibroids, and other ‘female issues’, it’s obvious why discussions need to focus on females, but why would that be true for heart disease? Well, having just returned home from just such a conference, I think I can explain. Today I was at the Washington DC Regional Symposium on Heart Disease in Women: 2013 Update on Prevention and Treatment, which was superbly organized by Dr. Daisy Lazarous, the Director of the Women’s Heart Program at MedStar Heart Institute.
Women’s physiology is inherently different in some ways, in part because of the balance of hormones that is determined by our genetic makeup (XX instead of males’ XY chromosomes). During that uniquely female adventure known as pregnancy, our bodies need to be able to adapt over a short period of time to a much larger blood volume and the changes that come with that, and then be able to change right back to our previous baseline. This requires a certain adaptability that would not be necessary in males.
The keynote speaker was Virginia Miller, PhD, from the Mayo Clinic Specialized Center Of Research on Sex Differences, who educated us on the difference between ‘sex’ and ‘gender’. Although I thought I had been using those terms appropriately, I now think I was mistaken. “Sex is biology,” she said. Sex refers to a person being male or female with defining characteristics including having testicles or lactating breasts. Gender, on the other hand, is a social concept that can vary by location and time, regarding what would be considered masculine or feminine. In the 1950’s, these might have included men smoking or driving, and women taking care of the household. When we talk about medical differences between men and women, then, the appropriate term is ‘sex’, whereas I had been using gender.
Now that we have clarified that, let’s get to the ‘heart’ of the matter. You may have heard about concerns that heart disease in women may be missed by physicians. What patients and doctors alike need to recognize is that coronary heart disease has been the #1 killer of females since 1908 – in fact it causes more death than the next 7 causes combined. The high rates of death occur in populations with the lowest awareness of heart disease – so being aware of the problem is the first step in improving outcomes. The good news is that deaths due to heart disease have decreased overall from 1990 through 2007; however, the rate has increased for 35-54 year old females, likely due to the obesity epidemic. For both sexes, chest pain is the most common symptom, and must be taken seriously. Women are more likely than men to present with fatigue, nausea, jaw or neck pain or shortness of breath; in the appropriate setting, we should pay close attention to these symptoms, as well.
Based on genetic makeup, women are predisposed to different kinds of vascular disease than men. These include high blood pressure in pregnancy, hot flashes of menopause and migraines. When they have chest pain, they are more likely to have spasms in the heart’s arteries than men are; men almost always have plaque, which requires different treatment. With heart failure women are more likely than men to have what looks like preserved function on an echocardiogram even when the heart isn’t functioning well, so may be misdiagnosed more often. Other disease states like high pressures in the arteries leading to the lungs (pulmonary hypertension) and POTS, a teen ailment with low pressure and dizziness are also more common in females.
The major risk factors for heart disease in males and females are high blood pressure (hypertension or HTN), diabetes, high cholesterol, smoking, family history and autoimmune diseases like lupus or rheumatoid arthritis. Heart disease and HTN occur 10 years earlier in men, but increase exponentially after menopause in women. After age 65 a higher percentage of women than men have high blood pressure. In black women in the US, that rate is an incredible 44%. Those who have a family history of HTN, are overweight, have sleep apnea or have had extreme HTN with swelling (eclampsia) in pregnancy are at particularly high risk of having HTN in their lifetime.
Diabetes is another major risk factor for heart disease, which unfortunately is increasing with the obesity epidemic. There is a great deal of evidence that we can reverse or at least slow the elevated blood sugars associated with pre-diabetes with good nutrition and moderate exercise preferably 30 minutes on most days. The exercise improves risk on a continuum – any amount is better than none, and the more you do, the greater the risk reduction.
Regarding cholesterol, women have some advantage in that HDL, the protective portion, is higher on average in females from puberty onward. However, the non-HDL, more plaque-inducing particles increase after menopause, and add to the increased risk of heart disease in women.
Over the past five or six decades, many studies have been done regarding the natural course of heart disease and many of the medications used to treat it. Those studies included mostly males. It turns out that animals used in medical tests are also males or undefined. Even when human females were involved, it wasn’t specified what their hormonal state was at the time – i.e. menstruating, peri- or post-menopausal. As we learned from Geetha’s article, timing is everything with respect to hormone replacement. She told us that if estrogen is started for hot flashes when the coronary arteries are clean it should not cause heart disease, but may increase plaque if it has already started to form. We need to know if other treatments would also depend on hormonal status. It’s not that treatment is necessarily different for men and women, but it’s important that studies are done to show whether the same treatments work in the same way. Recently, it was confirmed that statins which are used to treat high cholesterol do, in fact, work equally well in females.
Now that you know about major risk factors for heart disease, what can you do to avoid or limit your need for medications? If you or someone close to you, of either sex, seems to be at increased risk, it is critical that you have regular checkups and tell your doctor about your risk factors, including any problem with HTN or diabetes during pregnancy. Keep your blood pressure, weight and salt intake down, aim for a nutritious, plant-rich diet, sleep 7-8 hours a night and try to reduce stress (with exercise 😉 ). Any progress you can make in this direction is helpful. The best time to address all of these is before any problem is evident. It’s so much better than trying to play catch up! Plus, with healthy lifestyle modification, maybe we can help reduce our 2.1 trillion dollar annual health expense – a major topic for another time!