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RISK FACTORS FOR OUR CARDIOVASCULAR SYSTEM

The subject of this article is the risk of high blood pressure, which is itself a dangerous disease. If we also go into other risk factors in some detail, we do so because a risk factor generally does not exist all by itself, and because common sense dictates that we try to identify and eliminate all existing risk factors and potential hazards. To attack only one factor is as pointless as equipping your car with the very best safety belts money can buy while driving with worn tires and defective brakes.

We know that risk factors are closely linked to the way we live. High blood pressure, diabetes, and metabolic disorders are diseases of the prosperous society. Because the malnourished peoples of the developing countries are generally too poor to "afford" these risk factors, cardiovascular diseases are not very common among them. But as their economic situation improves and they acquire some of the living standards of the industrial nations, their rate of cardiovascular disease also goes up.

Excess weight. This promotes the development of various risk factors and thus, by itself, constitutes a serious health hazard. 85% of all diabetics, 80% of all persons with abnormal blood levels of cholesterol and/or triglycerides, 70% of all cases of hyperuricemia (an excess of uric acid in the blood), and 60% of all hypertensives are overweight. The major cause of overweight is overeating. A further cause is lack of exercise, the occupational disorder of so many who spend their working life behind desks, factory benches, or the wheel of a car.

Abnormal fat metabolism. The serum fats, also known as lipids, supply the body with energy and building material. In part they are taken in with the food we eat and in part they are composed by the body itself. If, as a result of a poor diet, the body receives more fats than it needs, then the blood fat level rises.

A chronically high blood fat condition (hyperlipidemia) can trigger and accelerate the degenerative processes of the arterial wall—the condition we call arteriosclerosis. Two types of blood fat«0-cholesterol and triglycerides, and particularly cholesterol—play a crucial role in this. Cholesterol is largely produced by the body itself, but the blood cholesterol level is linked to our diet, to the type of fats we eat and the cholesterol contained in our food. The body is able to convert carbohydrates like sugar, flour, bread and bread products into fats known as triglycerides. Two Norwegian epidemiologists, Westlund and Nicolaysen, found that middle-aged men with a blood cholesterol level of more than 250mg% run a higher than average risk of heart attack, and the risk increases substantially as the level rises. The cholesterol level has been called a warning signal of unique predictive ability.

Because an elevated blood triglyceride level may also be a hazard it should not be ignored.

Smoking. Cigarettes are a significant risk factor in cardiovascular disease according to a study of the World Health Organization made in 1965. And the Framingham study lends support to this finding. Whereas people who smoke one pack of cigarettes a day are three times as likely to suffer a heart attack than nonsmokers, the risk increases as consumption goes up; with chain smokers the chances for heart attacks are six times those of nonsmokers.

The most important information for the ex-smoker is the fact that the risk of heart attacks, within a short period of time, returns to the level of nonsmokers.

Diabetes. The Framingham study also makes clear that one out of every two diabetics sooner or later suffers blood vessel damage and runs an increased risk of heart attack, The incidence of hypertension among diabetics is greater than among non-diabetics in the same age group, and it is just as high for men with diabetes as for women. The link between the two risk factors, diabetes and hypertension, explains the relative frequency of coronary disease among people with both conditions. And there is a still more important association between untreated or inadequately treated diabetes aft blood vessel disease (arteriosclerosis) of the legs; in extreme cases it can lead to diabetic gangrene and must be treated by amputation of toes or of the entire leg.

Hyperuricemia (the accumulation of uric acid in the blood).

Hyperuricemia is a metabolic disorder with potentially

very painful consequences. The body converts this excess uric acid into tiny crystals which may lodge in the joint tissues. The result is the painful disease known as gout. As early as 1899 a French physician by the name of Huchard stated that this excess of uric acid affected not only the joints but also the arteries. Because hyperuricemia often appears associated with overweight as well as with high blood pressure, diabetes and abnormal fat metabolism, we are still not certain whether it deserves to be treated as a risk factor by itself. One important aspect is that people with high blood pressure are three times as likely to suffer coronary heart disease as hypertensives with normal uric acid levels in the blood.

Stress. Stress has become a popular term used to explain everything from simple headaches to serious disorders. We hear and read about it at the dinner table and on TV talk shows, in the papers and magazines. But what does it mean? Professor H. Selye, the inventor of the stress concept, applied it to the protective "alarm mechanism" of the body against overburdening. Under stress the nervous system goes into "high gear" and triggers the production of large amounts of hormones to raise the body's defenses and resistance. Stress reactions can be set off by a vast array of different conditions—by cold and heat, infection and injuries, by psychological and emotional strain.

Whether this ordinary stress will turn into a permanent condition, i.e., into a constant stimulant of the defense mechanism, and whether this persistent pressure to operate at "high gear" will ultimately put an undue burden on the cardiovascular system depends on a variety of factors, primarily on the nature of the stress and on its impact and duration. Professor L. Levy of Sweden has compiled a list of the stresses of everyday life as defined by medical psychology. Among them are:

The oppressive demands created by the conflicts about our "role" in our various life situations—i.e., our work, marriage, relationship with our parents, etc.

The oppressive demands created by unanticipated and sudden changes in our lives, such as job changes and transfers, job insecurity, and similar radical inroads calling for major readjustments.

The inability to adjust to new life situations and settings because of discrepancy between expectations and reality in business and personal life.

Whether this sort of stress turns into a risk factor seems to depend on the individual, on his or her "stressability." Dr. M. Friedman and Dr. R. H. Rosenman have written a book in which they characterize the stress-prone individual as one who lives by the clock, who speaks rapidly and in a tense manner, who doesn't listen, who tries to do more than one thing at a time, who always wants to outdo others, who is unable to enjoy himself, who grinds his teeth. A person of this type lives rather dangerously; not so much the stress, but his own personality may constitute a risk factor.

Many readers will recognize themselves or others in this description. Yet much of this is merely a theory, a working hypothesis. Research on stress is still in its infancy, and the lack of objective research methods complicates matters. This is because stress, unlike other risk factors or blood pressure, cannot be measured in numbers, nor, unlike smoking does it lend itself to comparative studies. Just as some people are more thin-skinned than others, some are more prone to stress than others. In other words, different types of stress affect different people differently and evoke different physical reactions.

That is why medical science, although admitting that stress may be harmful, does not, in the absence of conclusive proof, accept it as the major causal factor of cardiovascular disease. Contrary to popular belief, stress plays a much smaller role as a risk factor than do poor dietary habits.

Professor Selye, in his book on stress, maintains that stress is not merely nervous tension. "The absence of stress is death," he writes, and goes on to say that it matters little whether a given situation was triggered by pleasant or unpleasant circumstances; what matters rather is the adjustment required. As a physician in daily contact with people who have had to cope with highly stressful situations, he has been in a position to observe the effects on their health.

The widespread preoccupation with and misconceptions about stress as a risk factor have been further helped by the superficial coverage of the various media. It is for this reason that I have gone into this matter in some detail. I will return to it in the discussion on the causes of high blood pressure.

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