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www.heartcharity.org
About Heart Disease
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The broad term "heart disease" really refers to cardiovascular disease - a condition that affects the arteries' ability to deliver blood to the heart. We're not talking about the ability to get blood into the chambers of the heart for circulation back to the body, but the ability of the vessels to deliver blood to the heart muscle so that it has enough oxygen to sustain its constant contractions. When the blood supply is cut off, usually due to a blood clot lodging in an artery already narrowed by fatty plaque, part of the muscle dies and the heart can't beat properly. The heart's well being is dependent on keeping the vessels open so that enough blood is delivered to it. Minimising cardiovascular risk factors The standard line has always been that women are protected from heart disease as long as their bodies make oestrogen, and then they lose protection. However, it may be true that heart disease is simply a disease of ageing. Like grey hair, it's more common in postmenopausal women than in premenopausal women because postmenopausal women are older. Risk factors Although genetics can be a factor in heart disease - particularly, in people who develop it early in life, most of the factors that increase our risk for it are readily modifiable. In fact, for most of us, most heart disease can be prevented by lifestyle changes, probably through diet and exercise alone. Cholesterol Some types of cholesterol are more important for women than for men. In general a total cholesterol of 200 or less, HDLs above 35, LDLs below 160, and triglycerides of 200 or less are considered acceptable. As we age, it becomes harder to meet this goal because our HDLs tend to fall and our LDLs rise, particularly if we gain weight - a factor that may be related to menopause. Hypertension High blood pressure, like cholesterol, can also lead to heart attacks. The blood exerts greater stress against the vessel walls, increasing the chance of plaque rupture - one of the early steps in heart attack - and aneurysm -weakened, ballooning blood vessels that lead to stroke. High blood pressure is defined as systolic pressure of 140 or higher, and a diastolic pressure of 90 or higher. Diabetes Diabetes is a disease of sugar metabolism. There are two kinds. The first occurs in childhood and is called insulin-dependent (formerly called juvenile) diabetes. The body fails to produce enough insulin, the hormone that regulates sugar levels in the blood. People with this form of diabetes take daily insulin injections to compensate. The second, more common, form of the disease is called adult-onset, non-insulin-dependent, diabetes. In this case, the body makes insulin but for some reason it is unable to use it. Adult-onset diabetes develops most often in people who are obese, who come from families with diabetes, or who have high blood pressure. Uncontrolled diabetes of either type has a treacherous effect on the body's very small arteries. Diabetes doubles a woman's risk of coronary heart disease. Someone who has diabetes in addition to high blood pressure, obesity, high cholesterol, and high triglycerides, has four times the risk of heart disease as someone with none of these risk factors. In fact, 80 percent of diabetics die of heart attacks. Moreover, when a diabetic women has a heart attack, she's more likely to die from it than either a man who has diabetes or a woman who doesn't. Obesity Obesity is defined as someone who is more than 20 percent over the target weight for their height. These days, target weight is defined in terms of body mass index - a value derived by dividing height in meters squared by weight in kilograms squared (For those of us who aren't on the metric system the equivalent is weight times 700 divided by height in inches squared.) The range of normal for body mass index is 18.5-25. A BMI of 27 or greater - particularly if waist measurement is over 35 inches -- is a strong risk factor for coronary heart disease in women. Here is where the famous apple/pear shapes factor in. Women who have a high ratio of waist to hip (the apples) have a greater risk of heart disease than those who carry their fat in their hips (the pears). The risk is thought to be due not to subcutaneous fat (the "pinchable"inches around the waist) but to visceral fat - the internal fat that serves as a cushion for the organs. One theory is that by-products of this fat drain into the liver where cholesterol is manufactured and influence the production of more cholesterol. Lifestyle factors can reduce heart disease Sometimes we get so tuned into the high-tech promises of medicine that we overlook the low-tech approaches to good health, which can be equally if not more effective. We also lose sight of the fact that lifestyle changes - eating better, getting enough exercise, and reducing stress - can improve your day to day existence in ways that no pill can. Start with a complete physical exam and blood cholesterol test before you begin any new diet or exercise program. It helps to know where you need to focus your efforts as well as the limits you may need to impose on yourself. Exercise You've probably heard enough about the benefits of exercise to last you a lifetime, but here they are again in a nutshell: If you are sedentary, you can reduce your risk of dying of a heart attack by 50% if you get fit. What's fitness? A recent report from the Nurses' Health Study suggested that it's the product of 3 hours of brisk walking or the equivalent each week. This is a total - it doesn't have to be done at one time - you can spread it out in 10-minute increments if you like. But you do have to be moving at a fairly good clip - you should be able to talk, but not to sing. Diet In these days of conflicting health messages, the heart authorities and cancer experts have done us a favor by coming up with similar dietary recommendations: 5 servings of fruits and vegetables a day, fat held to 30% of calories and saturated fat to 10%. If you eat 1,500 calories a day, aim for about 56 grams of protein. Consume 30-35 grams of fibre, preferably through fruits, vegetables and wheat bran. Don't skimp on dairy products (calcium prevents high blood pressure as well as osteoporosis) but make them low-fat. Finally, it's almost impossible to overstate the benefits of soy. There is evidence that it lowers cholesterol and dilates blood vessels. In fact, the FDA recently allowed manufacturers of soy products to promote it as a heart-healthy food. Quit smoking There is no question that smoking is the single most dangerous thing you can do for your overall health. Smoking increases infertility and the rate of miscarriage. It causes premature menopause (and wrinkles). It increases the risk of adult-onset diabetes (a risk factor for heart disease). Smoking is an enormous risk factor for heart disease. And it doesn't take much of it. Women who smoke as little as half a pack a day may have a 50 percent increased risk of heart disease compared to women who have never smoked. Smoking a pack or more a day (20 cigarettes) may have a 100 percent increased risk for women. Smoking also dramatically increases your risk of osteoporosis. In addition, it causes emphysema, cervical cancer, lung cancer, bladder cancer, cancer of the nose and mouth and throat, and cancer of the oesophagus. In some ways smoking is even worse for women than it is for men. A woman who smokes the same amount as a man is more likely than he is to get lung cancer. If you're on estrogen replacement therapy, you increase this risk even more. If you quit, expect heart disease risk to drop by 14 percent within two years. After 10 to 14 years your risk is scarcely higher than that of people who never smoked. Giving up smoking is never easy. It's both a physical and an emotional addiction. Studies show that the most common reason women give for not quitting is fear of weight gain. And, for many women, smoking is a stress reducer. If you really want to quit, you must develop other methods of losing weight and reducing stress before you try. Exercise is good for stress, and you might give yourself permission to gain an extra 8 to 10 pounds temporarily. Depriving yourself of too much all at once may lead you right back to smoking. There are lots of smoking cessation programs out there-nicotine gum and patches, support groups, hypnosis, acupuncture. And if it doesn't work the first time, try another approach. Don't give up. It often takes several tries before you can really quit. Drugs to reduce heart-disease risk When diet, exercise, and other lifestyle changes aren't enough to keep your cholesterol down, there are cholesterol-lowering medications available. These range from drugs that block cholesterol absorption, to drugs that block the body's system for making cholesterol. When one drug alone doesn't work, you may try them in combination. As with osteoporosis, I have confidence that we'll eventually have better ways to treat coronary heart disease and to predict when women are at risk. Cholesterol-lowering drugs There is no question that in observational studies, oestrogen appears to have substantial benefits. Reviews of the observational studies that looked at a connection between oestrogen and heart disease indicated that women who took oestrogen - even with a progestin - had only about half the risk of heart attack as those who didn't take it. However, it has long been argued that because women who took oestrogen were likely to have seen doctors regularly and to have better health habits than those who didn't, they were less likely to have heart attacks, with or with out oestrogen. Oestrogen for preventing heart disease The first major randomised controlled study that lasted long enough, indicated that oestrogen couldn't prevent a heart attack - at least for women who already had heart disease. Women in HERS (Heart and Oestrogen/Progestin Replacement Study), who received HRT had no benefit, even though their LDL levels fell 11% and their HDL levels climbed by 10%. Those on HRT had 50% more heart attacks during the first year although they had 40% fewer in the last two years of the 4-year study. The HERS findings may be more in line with those of other studies than they appear to be at first glance. Five or ten years of improving cholesterol should put off heart disease for 5-10 years; but it doesn't. When the cholesterol-lowering effect is teased out of the data from large studies, it appears that only one fourth to one third of the reduction results from better cholesterol levels. The majority results from oestrogen's ability to dilate blood vessels. This effect, which disappears when women stop taking oestrogen, would seem to make oestrogen more valuable in treating heart disease than in preventing it. Aspirin Aspirin doesn't lower cholesterol, but it seems to prevent heart attacks by decreasing the blood's ability to clot. You should take aspirin for this purpose only under a medical doctor's supervision. Aspirin may be common, but it's still a drug, and it can have serious side effects when taken over the long term. |