Are You at Risk for Hypertension?
Essential hypertension has no known cause. As a result, identifying clear risk factors is difficult. Researchers have discovered a few patterns, however. Some you have no control over — for example, you can’t alter your genes. But others, like smoking and heavy drinking, are habits you can change.
Risk factors you can’t change
Even though you can’t control these risks, that doesn’t mean you can forget about them. Awareness of your risk factors can help you put your overall cardiovascular risk profile into perspective and may provide you with an extra incentive to adopt healthier habits.
One in three African Americans is hypertensive, as opposed to one in five people in the general population. In addition, the disorder often develops earlier and with more ferocity in African Americans than in other races. African Americans are nearly twice as likely to suffer a fatal stroke, one-and-a-half times more likely to die from heart disease, and four times more likely to suffer kidney failure than are whites. For black men, the picture is particularly disturbing — they face a death rate from high blood pressure that’s nearly three times that of the overall average.
The high incidence of hypertension among African Americans may have a genetic explanation. Some researchers suspect that people who lived in equatorial Africa developed a genetic predisposition to being salt sensitive, which means their bodies retain more sodium. This condition increases blood volume, which, in turn, raises blood pressure. Salt sensitivity can be beneficial in a hot, dry climate because it allows the body to conserve water. Generations later, however, the American descendants of these individuals remain disproportionately salt sensitive.
Hypertension, like many disorders, runs in families. In addition, a family history of heart attack, stroke, diabetes, kidney disease, or high cholesterol increases your risk of developing high blood pressure.
This doesn’t necessarily mean, however, that genetics always plays a role. Some of the similarities observed in families may be the result of environmental influences. Children’s eating patterns, coping skills, and propensity toward healthy and unhealthy habits are shaped by their parents’ behavior and the social climate in which they’re raised.
Research indicates that about 25% of cases of essential hypertension in families and up to 65% of cases of essential hypertension in twins may have a genetic basis. In addition, at least 10 genes have been found to influence blood pressure. So far, however, only a few studies have identified a link between particular genes and hypertension.
Although aging doesn’t invariably lead to hypertension, high blood pressure becomes more common in later years. Diastolic pressure increases an average of 10 mm Hg up to age 55 in men and age 60 in women, and then begins to decline. Between ages 30 and 65, systolic pressure increases an average of 20 mm Hg, and it continues to climb after age 70. This age-associated increase largely explains isolated systolic hypertension.
Up to about age 55, women have a lower incidence of hypertension and other cardiovascular diseases than men do. But women’s blood pressures, especially the systolic readings, rise more sharply with age. Indeed, after age 55, women are at greater risk for high blood pressure. This pattern may be partly explained by hormonal differences between the sexes. Estrogen tends to protect women against cardiovascular diseases, including hypertension, but as the production of estrogen drops with menopause, women lose its beneficial effects and their blood pressures climb.