Risk Factors
During the last decade, the number of Americans with high blood pressure has increased by 30%. Over 65 million American adults now have high blood pressure, and this condition affects close to 1 billion people worldwide. Less than half of these people are on medication, however, and only about half of this group have their blood pressure under good control with such drugs. Older people are less likely to be treated adequately. The majority of people with high blood pressure have the mild type, but even this condition requires attention.
Age and Gender
Age is the major risk factor of hypertension. Blood pressure increases with age in both men and women, and, in fact, the lifetime risk for hypertension is nearly 90%. Two-thirds of Americans over age 60 have hypertension. Older women (60 years and above) currently have the highest rates of hypertension, and mortality rates from hypertension are higher in women than in men. Hypertension is also becoming more common in children and teenagers.
Ethnicity
Compared to Caucasians, Americans are much more likely to die of stroke, heart disease, and end-stage kidney disease. In general, about a third of African-American men and women have hypertension; it may account for over 40% of all deaths in this group. High blood pressure tends to start at a younger age among African-Americans, is often more severe, and causes greater target organ damage.
The rates of hypertension in Hispanic Americans, Caucasians, and Native Americans are similar and are lower than in African-Americans. The rate is much lower in Asian/Pacific Islanders. However, nearly 75% of older Japanese American men are hypertensive.
A number of theories have addressed the reasons for this difference. It may have to do with levels of, or different response to, various body proteins involved in the control of blood pressure. Social and income disparities and dietary issues may also explain many of the differences in blood pressure rates observed between ethnic groups. For example, while African-Americans have a disproportionately high rate of hypertension, one study in rural African villages, where diets are rich in fish, reported only a 3% rate of high blood pressure among inhabitants.
In any case, hypertension appears to be dangerously undertreated in major minority groups. Inadequately controlled hypertension is the major factor for the higher mortality rate from heart disease among African-Americans, and special treatment considerations need to be addressed in this population. African-Americans often need at least two medications to help lower their blood pressure.
Obesity
About one-third of patients with high blood pressure are overweight. Even moderately obese adults have double the risk of hypertension than people with normal weights. Moreover, the increase in blood pressure in aging Americans may be due primarily to weight gain. (In other cultures old age does not necessarily coincide with weight gain or high blood pressure.) Children and adolescents who are obese are at greater risk for high blood pressure when they reach adulthood.
