In this chapter, we’ll explore two of the most important biological factors in determining risk for silent heart disease: gender and age. Typically, a discussion of these two factors would begin with how middle-aged men are at the highest risk for heart attacks, and that’s true: men are ten times more likely to have a heart attack than women prior to the age of forty-five. But for men and women ages sixty to seventy-nine, women actually have slightly more coronary heart disease than men: 70.2 percent of men versus 70.9 percent of women.
So rather than follow tradition, let’s switch the focus on gender and age from men to women. Why? Because women share all the traditional risk factors for silent heart disease—high blood pressure, high blood sugar levels, high cholesterol levels, positive family history, smoking, and obesity—but also experience another subset of factors specific to them. (By the way, the terms “gender” and “sex” traditionally have been used interchangeably. For our discussion in this chapter and elsewhere in the book, we mean the biological differences between women and men when we refer to gender.)
First, however, let’s bust another myth: heart disease is largely a men’s disease. While it’s true that heart attacks strike men at younger ages than they do women, the survival rates for women are worse. And for both sexes, heart disease is the number one killer. That might surprise many who think breast cancer must be the leading cause of death among women. However, more than two hundred thousand women die each year from heart attacks—five times as many as from breast cancer. Because women’s symptoms are “atypical” (to use old-school parlance) compared to men’s, they might be at least partially more susceptible to silent heart disease.
Medical science has a long tradition of essentially ignoring women. Until recently, human trial studies for new medications would only use men as test subjects. Such studies are the gold standard for testing the efficacy of a new drug and are required by the Food and Drug Administration before a drug is approved for sale to the public.
So, why would they do that? I mean, with women making up roughly half the population (50.8 percent to be exact), it would seem reasonable to assume that half the test subjects would be women. How about even 25 percent? It took effort to purposely exclude women from these studies. So, why do it? The most common reason given was that women are too “hormonal” (meaning that women’s female hormones, like estrogen, are not found in the male anatomy), which would “confound” the findings.
At this point, I realize many women readers’ jaws may have dropped wide open. On the other hand, they might not be surprised at all.
Today, medical researchers realize that excluding women from trial studies has a potentially serious impact on women’s health. On the most basic level, women tend to be smaller than men, so the same prescriptive dosage for a man might not be appropriate for a woman.
Similarly, cardiologists have tended to view women’s treatment through a male-centric lens. Under the microscope or on an MRI, a woman’s heart may look just like a man’s, but in fact there are significant differences that may affect the risk factors for a heart attack. For example, men and women physically react differently to stress. Her stress results in a rising pulse rate. His stress translates into increasing blood pressure.
A woman’s heart is typically smaller than a man’s, and the walls dividing the chambers are thinner. While a woman’s heart pumps faster, each heartbeat is also about 10 percent less efficient than in men.
All very interesting, you might surmise, but what does that have to do with coronary heart disease and specifically silent heart disease? The answer is that gender impacts how heart disease symptoms manifest and how best to treat them.
These are the most important ways women’s risk factors for heart disease differ from men’s:
1.Women have more physical risk factors.
2.Women are older when they experience their first heart attack.
3.Heart attack symptoms can be different from those in men.
4.Some diagnostic tests aren’t as effective in women.
5.Women take longer to receive medical care for their heart disease.
6.Women tend not to recover as well from a heart attack.
7.Hypertension is higher in older women.
8.Women have more lifestyle obstacles then men.
Let’s dig a little deeper into each one.
Women’s bodies, by virtue of their reproductive system, are more complex than men’s. There are diseases that only, or primarily, affect them, such as breast cancer, ovarian disease, and endometriosis. (Research shows that endometriosis, a painful disorder in which tissue that normally lines the inside of the uterus grows outside it, increases the risk of developing heart diseases by 400 percent in women under forty.) Speaking of breast cancer, new research indicates that women have a higher risk of heart disease after being treated with chemotherapy or radiation therapy. Additionally, many women may choose antiestrogen therapy if they have an estrogen-sensitive breast cancer, and loss of estrogen may be associated with higher risk of heart disease. With 3.1 million women estimated to develop invasive breast cancer each year, this poses a significant health risk for the nation. Finally, women with diabetes are at greater risk of heart disease than men with diabetes.
On average, women are five to ten years older than men when they have their first heart attack. It’s thought that the female hormone estrogen is protective of women to some degree. Consequently, their risk of heart attack increases with menopause, and there’s virtually no difference between men and women’s risk of heart attack by age seventy. At first glance, that might seem a distinct advantage for women, but it comes with its own risk. Heart attacks in younger, premenopausal women can be missed by the women themselves and their physicians because they are relatively uncommon. In fact, every year in the United States, heart disease kills sixteen thousand women ages thirty to fifty-five and results in forty thousand hospitalizations.
Studies suggest that women are more likely to have a wider range of symptoms not typically associated with heart attacks. The classic symptoms of chest pain and crushing pressure or weight are simply absent in many women with an acute heart attack. Instead, women have different symptoms that are often shared with other afflictions, such as sudden and dramatic fatigue, excessive sweating, and pain in the neck, back, or jaw—symptoms that might be misdiagnosed as associated with lupus, menopause, or stress.
Heart disease can be more difficult to diagnose in women. An angiogram is among the most effective and widely used X-ray tests for finding blockages in the heart’s arteries and a key diagnostic tool in determining and preventing silent heart disease. But coronary heart disease in women, more often than in men, affects small arteries, which are more difficult to see in X-rays.
In a recent study of fifty people age sixty-five and older, researchers found that women hospitalized for heart disease were less likely to receive beneficial medications, including everything from the most basic, like aspirin, to the latest cholesterol-lowering pharmaceuticals. Research also shows women tend to arrive in emergency rooms later than men, after heart damage already has occurred. Again, their so-called atypical symptoms may be at play here, with women downplaying or misinterpreting warning signs of an acute heart event.
Women who suffer a heart attack on average require longer hospitalization than men and are more likely to die before leaving the hospital. Social-psychological factors may be at work here: perhaps it’s a reflection of women putting their families’ health and welfare before their own. Or the reasons may have more to do with other untreated illnesses more prevalent in women than men, including diabetes and high blood pressure. Or it may be the case that women don’t receive the right medications. We know, for example, that women have a greater risk of developing a blood clot following heart attacks yet are less likely to be given drugs to prevent blood clots.
More than 45 percent of U.S. adults have high blood pressure or hypertension, a leading risk factor for silent heart disease. While hypertension is lower among young women compared to men of the same age, the reverse is true for the elderly.
We often think of depression as affecting mainly the brain. But new research is showing that depression can increase inflammation, in turn leading to atherosclerosis or blockage of the arteries. Women’s hearts seem to be more impacted than men’s by depression. Stress and depression can also make it more difficult to maintain a healthy lifestyle regimen, such as following treatments, eating a healthy diet, or getting a good night’s sleep. Smoking is detrimental to everyone’s health, but in women smoking poses a greater risk factor for heart disease than in men. Some studies even indicate that a sedentary lifestyle is more of a risk factor for heart disease in women than in men.
Now let’s turn to another major risk factor for silent heart disease: aging. People age sixty-five and older are much more likely than younger people to suffer a heart attack, to have a stroke, or to develop coronary heart disease (commonly called heart disease) and heart failure.
Aging can cause changes in the heart and blood vessels. As you get older, your heart doesn’t beat as fast during physical activity or during fight-or-flight times of stress. However, your heart rate (the number of heartbeats per minute) at rest does not change significantly with normal aging.
As we learned earlier, a major cause of heart disease is the buildup of fatty deposits in the walls of arteries over many years. The good news is there are things you can do to delay, lower, or possibly negate or reverse your risk.
The most common aging change is increased stiffness, or hardening, of the arteries. In turn, this causes high blood pressure, or hypertension, which can further damage the heart, and so a downward spiral of cause and effect begins.
Age can cause other changes to the heart:
•Age-related changes in the electrical system can lead to arrhythmias—a rapid, slowed, or irregular heartbeat—and/or the need for a pacemaker.
•Valves—the one-way, door-like parts that open and close to control blood flow between the chambers of your heart—may become thicker and stiffer. Stiffer valves can limit the flow of blood out of the heart and become leaky.
•The chambers of an aging heart often increase in size. As the heart wall thickens, the amount of blood that a chamber can hold diminishes, despite the increased overall heart size. The heart may fill more slowly.
•Long-standing hypertension can cause an increased thickness of the heart wall, which can increase the risk of atrial fibrillation, a common heart rhythm problem in older people.
•As we get older, we become more sensitive to salt, which may cause an increase in blood pressure and/or ankle or foot swelling (edema).
So, age and gender are both significant factors in the risk of developing silent heart disease.
One more thing: I would be remiss if I didn’t conclude this chapter with a final comment about aging. Generally, the older you are, the higher risk you have of coronary heart disease, and the majority of people who die of coronary heart disease are sixty-five or older. That’s been dogma ever since the medical profession began observing heart disease centuries ago.
But in a new study released in May 2019 by the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Health and Human Services, more middle-aged people today are dying from heart disease than in recent years, reversing a decade-long trend that witnessed heart disease rates declining for all age groups.
Experts believe the reason for this disturbing development is that rates of obesity, diabetes, and a sedentary lifestyle—all risk factors for heart disease—are going up for this age group. (We will explore all these factors in coming chapters.) But also, adults ages forty-five to sixty-four today are less likely to have medical insurance than they were ten years ago as more working- and middle-class Americans simply can’t afford it. Seniors tend to be immune to the health impact of stagnant wages and the lingering effects of the Great Recession, since they have guaranteed health care through Medicare.