Читать книгу The Slim Book of Health Pearls: Am I At Risk? The Patient's Guide to Health Risk Factors - Sheldon Cohen M.D. FACP - Страница 5

Although there are many diseases of the heart, we will limit our discussion to heart attack—the leading cause of death in the United States.

A heart attack is caused by hardening of the heart arteries, or coronary atherosclerosis.

Coronary refers to the coronary arteries, and the word atherosclerosis is of Greek origin: athero meaning pasty gruel, and sclerosis meaning hardness. So atherosclerosis is a process where fatty material, cholesterol, calcium, various cellular waste materials and other products slowly build up in the arteries inner lining forming a substance called plaque.

A sudden rupture of this plaque can cause the artery to completely obstruct resulting in the disruption of the blood flow to a portion of the heart muscle, which if large enough will cause death.

What this means is that the first symptom of coronary atherosclerosis may be quick death, so you must pay attention to the risk factors that can lead to this sudden, unexpected end.

Diseases of the heart risk factors

High blood pressure (hypertension)

As your heart pumps blood to your body, the degree to which it pumps depends upon the amount of resistance to blood flow in your arteries. The work load of your heart becomes greater as the resistance to the flow of blood increases. This puts a strain on your heart.

In addition, the effect of high blood pressure is to accelerate the process of atherosclerosis.

The risk for high blood pressure increases as you age and is also increased if you are overweight, or eat a diet too high in salt, or live a sedentary existence.

Blood pressure that can not be controlled by life-style changes (weight loss, low salt diet, exercise, stress reduction) demands anti-hypertensive medications. Failure to control high blood pressure by life style changes and medication demands a careful search for rare and unusual causes such as adrenal gland tumors or a blocked kidney artery.

Cigarette smoke (or any tobacco)

There are 4000 known chemicals in cigarette smoke and many of them are cancer producing agents, but cigarettes cause more heart attacks than they cause lung cancer and emphysema.

In the year 2000, worldwide there were 1,690,000 heart attacks among smokers. Contrast this statistic with the 850,000 lung cancer deaths due to smoking.

Tobacco smoke (first and second hand) is well known to cause damage to the inner lining of arteries by facilitating the process of atherosclerosis and promoting blood clots. This is an arterial “double whammy.” No wonder cigarettes are so potent in promoting heart attacks.

The effect, of course, is the same for all of your arteries, not just your heart. So, if you smoke, do all you can to stop. Seek help if you can’t. Your life may be at stake.

High blood cholesterol

Cholesterol is an important part of the artery deposits that form plaque and narrow your arteries.

Cholesterol can not dissolve in blood, so it combines with protein and then becomes soluble. This combination is called lipoprotein.

A high level of low-density lipoprotein (LDL) in your blood increases your risk for a heart attack, as LDL, or “bad” cholesterol forms part of the plaque. The level should be under 100, or as low as seventy if you have other risk factors.

High density lipoprotein level (HDL), or “good” cholesterol helps remove cholesterol from arteries. The level should be higher than forty, but the higher the better.

Total cholesterol level equals LDL plus HDL plus one-fifth of the triglyceride (see below—this formula is only valid if the triglyceride is less than 400). The total cholesterol should be less than 200. A cholesterol/ HDL cholesterol ratio has been used as a risk factor for heart attack. A ratio of less than four is considered a low risk. Three or two is better. The risk rises with an increasing ratio.

Knowing these levels of cholesterol in your blood is critically important. If the levels put you at risk, then corrective measures, including diet, exercise and possibly medication must be started.

Triglyceride

Triglycerides are derived from ingested fats, or are made in the body from carbohydrates. They are stored in your fat cells and are made available for energy requirements.

An elevated triglyceride (normal 150 or less) is another of the many risk factors for atherosclerosis, especially when associated with the so-called metabolic syndrome (pot belly, high blood pressure, low HDL cholesterol, diabetes, or a pre-diabetic state). This is why your physician may be interested in your abdominal measurement.

You are considered at risk if you are a man with an abdominal girth greater than 40 inches, (some put that measurement at 37 inches), or are a woman with an abdominal girth greater than 35 inches.

Why is this? To understand the reason you need to know that most of your fat is under your skin (subcutaneous fat), but of most concern is the fat that lies in your abdominal cavity called visceral fat—the fat that lies within your omentum, a cover of tissue that hangs down from the intestine and surrounds the organs within your abdomen.

Ordinarily you should not have more than ten percent of visceral fat, but if you have a pot belly, you may have twenty-five percent or more of visceral fat. The bad news is that there is a distinct correlation between visceral fat and diabetes and heart disease. So, it behooves you to rid yourself of your pot! And researchers have learned that if you eat the proper foods (much less saturated fats replaced by polyunsaturated fats), and get appropriate exercise (one half hour per day), you will lose your visceral fat.

This message is important regardless of your age, but is increasingly critical as you age, since the older you are the greater your risk for heart disease.

Exercise programs are also important for heart health, but should be started only with your physician’s approval.

So, if your triglyceride is elevated you will need to get serious about lifestyle changes:

If overweight, strive for ideal body weight by calorie reduction—reduce carbohydrates, fats and proteins.

Stop or greatly reduce your intake of alcohol, since alcohol raises triglyceride levels.

Eliminate trans fat. They promote hardening of the arteries.

Reduce saturated fat and cholesterol in your diet. They do the same.

Exercise for at least thirty minutes every day or as much as you can if approved by your physician.

Substituting carbohydrates for fat may elevate triglycerides in some people.

Salmon, sardines, mackerel, lake trout and tuna are rich in Omega-3 fatty acids, which may reduce triglyceride levels. So eat more fish and eat less red meat.

Diabetes mellitus

Diabetes is not a single disease. There are three major types:

Type 1 diabetes (insulin-dependant, also known as juvenile diabetes) is an autoimmune disease. Your immune system, instead of protecting you, destroys the insulin-producing beta cells in the pancreas. What triggers this is uncertain. Of all diabetics, ten to fifteen percent have this form. It can appear at any age, most commonly under forty. It is known as insulin dependent diabetes, because, to stay alive, daily insulin injections are required.

Type 2 diabetes, formerly known as non-insulin dependant diabetes, affects eighty-five to ninety percent of diabetics. This form of diabetes, striking later in life, is characterized by insulin resistance and relative insulin deficiency. Diet, oral medication and occasionally insulin injections are required for therapy. The disease is genetic in origin, but its development may be accentuated by overweight, inactivity, poor diet and high blood pressure.

Gestational diabetes mellitus (GDM) is diagnosed during pregnancy in about seven percent of pregnant women. It disappears after birth, but indicates that the mother is prone to developing type 2 diabetes, especially if overweight, and the baby is at risk for obesity and diabetes later in life.

Diabetes is a risk factor for heart disease because, if poorly controlled, the atherosclerotic process is accelerated and cholesterol levels rise.

Lack of exercise

Inactivity leads to weight gain, which can promote type 2 diabetes. The lack of activity plus the resulting overweight strains your heart by forcing it to pump more blood to an enlarged body. Regular physical activity can reduce the risk for heart and blood vessel disease, and can also help lower blood pressure.

Obesity

Overweight may result in diabetes. The more fatty tissue you have the more your cells become resistant to insulin. Obesity leads to inactivity with all its adverse consequences.

Stress

Intermittent stress can motivate, but when the sources are multiple and prolonged, stress can be a hazard to your health.

When you lose control of the stressful events in your life, adrenalin is released; your body develops a state of readiness to react to danger—your pupils dilate, your heart beats faster, your blood pressure rises, your breathing rate increases. You are ready for flight or fight. But you can’t flee and fighting would, in most instances, be undesirable, so you become irritable, angry and anxious, all signs suggesting you may be putting yourself at increased risk for heart disease.

So, it becomes important to cope: eliminate or reduce caffeine; exercise; eat balanced meals; learn how to meditate. Stress control is important. Get professional help if necessary.

Alcohol

Alcohol, in moderation (an average of one drink a day for women and two drinks a day for men), can have beneficial cardiac effects.

It increases HDL cholesterol and can inhibit clot formation. However, in excess, it enhances clot formation, can raise blood pressure, elevate triglyceride levels and promote visceral obesity—all cardiac risk factors.

Now, knowing all this, it is not recommended that you start drinking if you haven’t been, or if you have been, you start drinking more.

Family history

If your grandparents, parents, or siblings have had heart attacks, you may be at risk. Your family may have inherited a genetic condition that raises “bad” cholesterol and lowers “good” cholesterol.

High blood pressure also runs in families.

Smoking and/or exposure to second hand smoke as you grew up may play a role, as can poor family eating habits (high fat diets).

If your mother or grandmother or sister had heart trouble or a heart attack before age sixty-five, or your father or grandfather or brother had heart trouble or a heart attack before aged fifty-five, you are at greater risk.

Homocysteine

Homocysteine is an amino acid that has been implicated in the promotion of atherosclerosis by damaging the inner lining of arteries and promoting clot formation.

An elevated level has been postulated as increasing one’s risk for heart attack, as well as other vascular disease.

Folic acid and vitamins B-6 and B-12 break down homocysteine in the body, and, indeed, it has been shown that reduced blood levels of folic acid have been correlated with increased risk for heart attack and stroke.

Research is still being done on this correlation, so the American Heart Association has not yet called an elevated homocysteine level a cardiac risk factor, but they do endorse determining the level in those patients with a strong family history of heart disease.

If, in these patients, homocysteine is elevated, a diet high in fruits and green leafy vegetables should be consumed daily, and perhaps a multivitamin with folic acid and the B vitamins should also be taken.

C-reactive protein (CRP)

CRP is a protein found in the blood that is a marker for inflammation. In other words, an elevated CRP suggests that there is inflammation somewhere in the body. It is a non-specific test—something’s wrong someplace. It is important because inflammation has been shown to play a role in the initiation and progression of atherosclerosis and cardiac disease.

Specifically, a variation of the CRP known as highly sensitive CRP, or hs-CRP has been used to predict cardiac disease. If your hs-CRP is elevated, then you should go all out on risk factor prevention and your physician may choose to treat you with anti-clot medications such as aspirin or clopidogrel and may also consider the use of statin drugs and ace inhibitors to reduce the CRP.

In a clinical trial involving 18,000 physicians, an elevated CRP was associated with a three fold increase in heart attacks.

It has also been shown that an elevated hs-CRP applies also to an increased risk for stroke and peripheral vascular disease and the likelihood of closure of a coronary artery after angioplasty.

There are also some newer inflammatory biological markers whose worth is currently being evaluated.

Fibrinogen

Fibrinogen is a protein important in blood clotting, and too much of it may make your blood thick and sticky, an effect that you could do without.

People with levels too high are twice as likely to die of a heart attack.

Taken together with other risk factors it could add to the urgency of specific therapy such as the use of omega-3 fatty acids that have been shown to reduce fibrinogen levels, and the use of aspirin for its anti-clotting activity.

Cardiovascular disease risk factor questions

Is your blood pressure over 120/80? __Yes __No

Are you on any hypertension (high blood pressure) medication? __Yes __No

Do you have a pre-existing cardiac condition? __Yes __No

If so, are you under the care of a physician? __Yes __No

Have you ever had a heart attack? __Yes __No

Have you ever been told that you have angina? __Yes __No

About cigarettes: Check those that apply.

___I never smoked ___I smoke a few cigarettes a day ___I smoke 1 pack per day

___I smoke 1 to 2 packs per day ___I smoke 2 or more packs per day

___I quit smoking ___I inhale ___I do not inhale ___I smoke cigars

___I smoke a pipe ___I am exposed to second hand smoke

___How many years have you smoked?____

___I have quit smoking in the last 5 years.

Have you ever had a total cholesterol test? __Yes __No

Date of last cholesterol test_____

Is your total cholesterol greater than 200? __ Yes __No

Is your LDL cholesterol level higher than 100 mg/dl? __Yes __No

Is your HDL cholesterol level lower than 40 mg/dl? __Yes __No

Is your triglyceride level greater than 150? __Yes __No

Do you have Diabetes? __Yes __No

Would you describe the daily exercise you get as ‘minimal or none’? __Yes __No

Are you overweight? __Yes __No

What is your weight in pounds?____

For a man: Does your waist at your belly button measure more than 37 inches? __Yes __No

For a woman: Does your waist at your belly button measure more than 35 inches? __Yes __No

What is your height in inches?_____

Are you subject to unusual stress? __Yes __No

Do you drink more than two drinks a day? __Yes __ No

Did your grandfather, father, or brother have heart trouble or a heart attack before age 55? __Yes __No

Did your grandmother, mother, or sister have heart trouble or a heart attack before age 65? __Yes __No

Have you ever had any of the following blood tests: homocysteine, CRP, or fibrinogen? __Yes __No

You have taken your first risk factor analysis in this book. You will take more as you continue. When you finish, you should bring this information to your physician for his or her analysis.

You must be proactive as regards your health. This is crucial. Your physician may not be able to take the time to assess you completely in this way. Help him or her by identifying all your risk factors. Then together you both can decide what positive risk factors demand corrective action or specific therapy. Again, I repeat, early disease detection and prevention is the name of the game, and it can’t be done without a risk factor analysis—and a thorough and complete medical examination (the subject of my previous book: The Patient’s Guide to the Complete Medical Examination and the Prevention of Medical Errors—(see appendix 1.)