What You Cant Control Age Sex Family History - Recognizing And Reducing Risk Factors: Heart Disease

Content provided by the Faculty of the Harvard Medical School

What you can't control: Age, sex, family history

Some risk factors for coronary artery disease, such as age and sex, are unavoidable. But it's good to be aware of them so that you can counter innate risks by tackling those factors that are within your control.

Age

Heart disease becomes more prevalent with age in both men and women. Simply put, older people have more heart attacks than younger people do. More than four in five people who die from heart attacks are over age 65. Men over age 45 and women over age 55 are most at risk of having a heart attack.

Sex

Although heart disease remains the leading killer of both American women and men, there are significant differences between the sexes when it comes to symptoms and prognosis. On the other hand, the death rate from heart disease has declined for both men and women because more people are taking preventive measures, such as avoiding smoking and cutting saturated and trans fats from their diets.

Men are more at risk. Men are more likely than women to develop coronary artery disease, and usually at younger ages. After age 40, half of all men can expect to develop coronary artery disease, compared with one-third of all women. Moreover, the average age for a first heart attack in men is 65; for women, it is 70.

The prevailing wisdom for a long time has been that hormones explain much of this disparity. Estrogen appears to provide some heart-protective benefits to women until menopause, and researchers have long suspected that male hormones may contribute to heart disease in various ways. After all, athletes who abuse testosterone and other male hormones have a clearly increased risk for high blood pressure, heart attack, and stroke.

Yet studies examining testosterone's effects on the heart have produced mixed results. So the jury is still out when it comes to testosterone (not only in terms of its impact on the heart, but also on muscles, bones, and the prostate). It will take time for scientists to sort out the answers. In the meantime, men can reduce their risk by eliminating some of the bad habits that increase risk for heart disease.

Women have poorer outcomes. Women tend to develop heart disease 10 years later than men, probably because of the protective effects of estrogen. This hormone not only helps regulate the monthly menstrual cycle, but also has a beneficial effect on blood cholesterol levels, by raising HDL (good) cholesterol and lowering LDL (bad) cholesterol.

But when estrogen declines at menopause, so do its protective effects, causing a sharp increase in the risk for heart disease. Women who have gone through menopause are two to three times as likely to develop heart disease as women the same age who are still menstruating. For that reason, for many years doctors recommended hormone replacement therapy (HRT) to women who were entering menopause. But in 2002 and 2004, the heart-protective benefits of HRT came under fire when two major studies funded by the Women's Health Initiative found that HRT does not prevent heart disease, and in some cases increases the risk for heart attack. The consensus now is that hormone therapy should not be used to prevent heart disease in women. (For more details, see "Hormone replacement therapy.")

Women also differ from men in terms of cardiac health outcomes. Although women tend to be better than men at describing medical symptoms and seeking help, women have a 50% greater chance of dying from heart disease than men do. About 38% of women who've had heart attacks die within a year, compared with 25% of men. What's more, women are almost twice as likely as men to have a second heart attack within six years of the first. Women are also more likely to die in the hospital after coronary artery bypass surgery or angioplasty.

It is not clear why these disparities exist. A leading theory is that women are more likely to die because they tend to develop heart disease and have heart attacks later than men do. Another problem is anatomy: Women's hearts tend to be smaller than men's, making it more difficult for surgeons to stitch arteries together during surgery or keep them open after angioplasty. Women also are more likely than men to have coexisting chronic diseases, such as diabetes, by the time they undergo heart surgery.

However, some research has found that women may not be diagnosed as early or treated as aggressively as men. For instance, women who are having the symptoms of a heart attack are less likely than men to be admitted to the intensive- or cardiac-care unit and to get electrocardiograms, clot-busting drugs, or cardiac catheterization. After discharge from the hospital, they are less likely to be directed to a cardiac rehabilitation program (or to finish one), or to get counseling about nutrition, exercise, and weight loss.

The classic symptoms of a heart attack were identified largely in studies of white, middle-aged men; these symptoms do not always occur in women, which may contribute to delays in diagnosis and treatment. For instance, a 2003 paper that sought to better define heart attack symptoms reported that an astounding 43% of women who had heart attacks did not recall any type of chest pain, usually considered the hallmark symptom. Instead, the women reported shortness of breath, weakness, unusual fatigue, cold sweat, and dizziness.

What should you do if you're a woman? Perhaps most important, focus on steps you can take to prevent heart disease, and take medications if necessary to lower blood pressure and cholesterol (see "Medications for heart disease"). Second, learn more about what types of symptoms indicate you may be having a heart attack (see Table 9).

Family history and ethnicity

Coronary artery disease runs in families, and certain ethnic groups are more at risk than others. African Americans, Mexican Americans, Native Americans, and native Hawaiians, for instance, are all more likely than white people of European descent to develop heart disease. But are certain families and ethnic groups more at risk because of shared lifestyles such as smoking, diet, inactivity, or stress? Or does this situation reflect genetics, which may underlie risk factors such as high cholesterol, blood pressure, and blood sugar? The answer is both.

The genes an individual inherits are certainly important. Multiple epidemiologic studies have shown that people with a parent who developed coronary artery disease before age 55 are significantly more at risk than others for developing heart disease themselves. How great is the risk? Estimates vary, but this type of family history is clearly on a par with other major risk factors such as high blood pressure and cholesterol.

However, it's important to keep two things in mind. First, not every family history is equally worrisome; it takes a strong history (for example, a father or brother afflicted before age 55 or a mother or sister stricken before age 65) to increase your risk. Second, genetic research into heart disease remains in its infancy and many questions remain, particularly about what genes are most important in making people susceptible to heart disease and how these genes interact with other genes and environmental factors to increase or decrease risk.

Many studies are now under way to better understand the genetics of heart disease. The hope is that genetic testing will one day enable doctors to identify people at high risk for heart problems and perhaps help them avoid those problems with preventive treatment. In the meantime, if you have a family history of heart disease, it's vital for you to address risk factors like high blood pressure and elevated cholesterol, and adopt a heart-healthy lifestyle in your youth.

Last updated:	May 03, 2007