Feminine hearts: women should not underestimate their risk of developing heart disease

Although most women fear breast cancer, heart attack is the number one killer of American women--over 233,000 women die annually from heart attacks. Each year, approximately 18,900 females under age 65 die from coronary heart disease, with 35 percent under age 55. Younger women are also not immune to the ravages of this disease. "Data recently published by the Centers for Disease Control indicates that the number of younger women ages 35 to 44 suffering a sudden death actually increased during the '90s," says Sumeet Chegh, M.D., director of the heart rhythm research laboratory at Oregon Health Science University in Portland.

Women are often misdiagnosed because their symptoms are less obvious and differ from men's. Evidently, acute fatigue is a more common sign of an impending heart attack for women than chest pain. A study in the October 2003 issue of Circulation, which focused on more than 500 women who had suffered heart attacks in the previous four to six months, found that 70 percent experienced high levels of fatigue prior to their heart attacks. Forty-eight percent reported disturbed sleep for more than a month before their attacks and, surprisingly, only 30 percent experienced aching, tightness or pressure in their chests. In fact, 43 percent reported not having any chest pains during their heart attacks.

Risk Factors

There are a number of coronary disease risk factors. Some unchangeable risk factors include increasing age and heredity. Race is also a factor: African Americans have a greater incidence of heart disease than white Americans, largely because they tend to have higher average blood pressure levels, a heart disease risk factor.

What You Can Do

Fortunately, you can control other heart disease risk factors. The most well-known factor is cholesterol levels. High cholesterol levels in the blood contribute to the amount of plaque in the arteries, thereby increasing the incidence of coronary artery disease. It's best to keep your total cholesterol level below 200 milligrams per deciliter. Anything between 200 and 240 is problematic and levels above 240 are usually very dangerous.

In addition, keeping your weight at an optimal level through exercise and a low-fat diet is crucial for heart attack prevention. According to the landmark Framingham Heart Study, overweight people are more likely to develop heart disease, even if they have no other risk factors. Researchers, working under the auspices of the National Heart, Lung and Blood Institute (NHLBI) followed study participants for 50 years, from 1948 to 1998. After adjustment for known risk factors (e.g., age, gender, smoking, hypertension and cholesterol levels), heart failure risk for women increased 7 percent for each increment of one in the body-mass index (i.e., a measure of excess weight for height). Maintaining a healthy body weight is also closely associated with reducing high blood pressure and your chance of developing diabetes, two other heart failure risk factors.

Hypertension

High blood pressure, or hypertension, is a reading of 140/90 or greater. Although a higher percentage of men than women have high blood pressure until age 55, from ages 55 to 74 the percentage of women is a little higher. According to a study reported in the November 2003 issue of Circulation, high blood pressure and elevated levels of the inflammation marker C-reactive protein (CRP) may work together to increase cardiovascular risk in women. Researchers evaluated data obtained from 15,215 women and found that when levels of both CRP and blood pressure were elevated, the risk of heart attack increased eight times. Although heredity plays a part in the incidence of high blood pressure, cardiovascular exercise can greatly reduce both high blood pressure and cholesterol.

Diabetes

Close to 2.5 million American women are estimated to have high blood sugar or diabetes, according to the Society for Women's Health Research. Over 80 percent of diabetics die from a heart or blood vessel disease. Diabetic women's risk of heart attack is over double non-diabetic women's risk. Although diabetes can be hereditary, it can sometimes be controlled with exercise.

It is estimated that at least 20 percent of diabetics are overweight, which impacts glucose metabolism problems, including insulin resistance, a problem central to diabetes. Aerobic exercise mitigates this problem by opening bindingsites for insulin to be used by cells. In addition, weight-bearing exercise can be helpful because it also lowers insulin resistance and increases lean muscle. Because lean muscle mass increases metabolism, it helps burn excess body fat and thus lower heart disease risk. "I always recommend to all my female patients, not just diabetic ones, to do some kind of weight-bearing exercise at least every other day to decrease the risks of heart disease," says John Bauer, an internist in Portland, Oregon.

Exercise

It doesn't take much daily exercise to help strengthen your heart as well as decrease cholesterol levels. The American Heart Association recommends 30 to 60 minutes of moderately vigorous exercise three to four times per week. This can be jogging, running, swimming, aerobics or walking briskly (i.e., at least three miles per hour). The Nurses' Health Study at Brigham and Women's Hospital, which studied 121,700 women from 1976 to 1992, revealed that women who engaged in exercise at least three hours per week decreased their heart attack risk by 30 to 40 percent compared to sedentary women. Exercise's benefits on the heart may stem from its ability to reduce blood vessel inflammation, a risk factor for heart attacks.