High Blood Pressure and African-Americans

High blood pressure (hypertension) is a common condition in the United States. It's even more common among African Americans than among other ethnic groups. More than 40% of non-Hispanic blacks have high blood pressure. The American Heart Association (AHA) says that the prevalence of high blood pressure in African-Americans is among  the highest of any ethnic group in the United States.

African-Americans not only are at higher risk for high blood pressure, but they also get it at a younger age, and suffer more of the complications.

The problem is not confined to adults. Studies have shown that overweight African-American preteens may also develop high blood pressure.

The impact of high blood pressure on health is significant. It is a major risk factor for conditions that shorten life, including heart, blood vessel and kidney disease, and stroke. High blood vessel also causes many other complications including erectile dysfunction and vision loss. But, high blood pressure can be controlled and possibly prevented.

What is high blood pressure?

Blood pressure is the push of blood against the walls of your arteries. Blood pressure depends on two factors: how forcefully your heart pumps the blood and the amount of resistance in your arteries to blood flow. Blood pressure is recorded as two numbers. The systolic pressure, which is the pressure against artery walls as the heart beats, over the diastolic pressure, which is the pressure against artery walls as the heart relaxes between beats. Both numbers are important in determining if your blood pressure is too high.

According to the National Heart, Lung, and Blood Institute (NHLBI), an optimal blood pressure is a systolic level of less than 120 and a diastolic level of less than 80. Blood pressure is considered to be high if the systolic is at least 140 or the diastolic is at least 90. Just because your blood pressure is high in a single reading doesn't mean you have high blood pressure. A health care provider makes a diagnosis of high blood pressure only after several blood pressure readings on separate occasions show high blood pressure levels. If you have diabetes your doctor will diagnose you with high blood pressure if your readings are greater than 130/80.

A blood pressure between 120/80 mmHg and 139/89 mmHg is called pre-hypertension. If you are diagnosed with pre-hypertension, it means that you are more likely to develop high blood pressure in the future. If you have pre-hypertension and adopt a healthy lifestyle, you may be able to prevent the development of high blood pressure.

What are risks for high blood pressure?

Doctors don't know the cause of high blood pressure in most people who have it. Certain factors, however, make it more likely. Some factors cannot be changed, but others can. These are the risk factors for high blood pressure:

  • Age. The risk for high blood pressue increases with age.

  • Male gender. Men have a higher risk of developing high blood pressure than women earlier in life.

  • Blood relatives who have high blood pressure.

  • Smoking.

  • Overweight or obesity.

  • Alcohol. The risk rises for anyone drinking more than one ounce of pure alcohol a day. This means an average of more than two drinks a day for men and one drink per day for women.

  • Too little physical activity. The American Heart Association recommends an average of 40 minutes of moderately to high intensity activity 3 to 4 days a week.

  • Sensitivity to sodium (salt). In some people, eating too much sodium leads to high blood pressue.

  • Type 2 diabetes, gout, or kidney disease.

  • Pregnancy. Some women who do not have high blood pressure develop it during pregnancy.

  • Taking certain medications or herbal supplements. Certain medications and herbal supplements can raise blood pressure in some people. Common ones include steroids, ibuprofen, oral contraceptives, antidepressants, nasal decongestants and other cold remedies, and diet pills.

Why are risks higher for African-Americans?

At one time, researchers thought that certain genetic and biological differences accounted for the greater high blood pressure risk in African-Americans. Studies have not confirmed this, however. Experts are now investigating how socioeconomic disadvantages, diet, exercise, and other lifestyle factors may compound the genetic and biological risks. 

African-Americans appear to be more sensitive than people of other ethnic backgrounds to the effects of salt on blood pressure. They also have blood vessels that react more strongly to stimulation.

More African-Americans also are overweight or obese. According to the Centers for Disease Control and Prevention (CDC), more than half of non-Hispanic black women age 20 and older are obese, compared to about one-third of non-Hispanic whites.

According to the American Diabetes Association, 12.6% of non-Hispanic blacks, 20 years and older, have been diagnosed with diabetes. African-Americans are almost two times more likely to have diabetes than non-Hispanic whites.  

Social or economic variables that may account for the difference in high blood pressure risk include less access to health care and heath care information, and lower levels of education and income. Lack of resources for a healthy lifestyle and chronic stress from social factors such as higher unemployment and living in a disadvantaged neighborhood surrounded by noise, violence, and poverty are also factors, the AHA says.

More African-Americans also have other lifestyle habits that increase the risk for high blood pressure, the AHA says:

  • About 20% of black men and 14% of black women smoke.

  • African-Americans are more likely to have a diet high in salt, fat, and sugar, and low in vegetables and fiber.

How is high blood pressure prevented and treated?

The AHA says that African-Americans may be less likely to be aware of the dangers of high blood pressure. Mild to moderate high blood pressure usually does not cause symptoms, yet early treatment of high blood pressure helps prevent complications that shorten life. Anyone with any of the following conditions should have his or her blood pressure checked at least once a year:

  • Blood relatives who have had a stroke, heart attack, high blood pressure, or kidney disease

  • Type 2 diabetes

  • Overweight or obesity

If you have high blood pressure or pre-hypertension, you can lower your blood pressure by making changes to your lifestyle. Your health care provider can help you determine what changes you need to make and how to make them.

For healthy adults, these are the elements of a healthy lifestyle:

  • Not smoking or quitting smoking if you do smoke.

  • Maintaining a health weight, or a body mass index below 25.

  • Getting at least 30 minutes of moderately strenuous physical activity most days.

  • If you are African-American, the CDC and the AHA recommend eating less than 1.5 grams a day of sodium. Sodium is added to commercially processed or prepared foods and is in table salt. Buy low-salt or salt-free commercially prepared foods, and use little or no table salt.

  • Eating 2 cups of fruit and 2-1/2 cups of different colored vegetables a day.

  • Eating fewer foods from animals to avoid saturated fat.

  • Using only non-fat or low-fat dairy products.

  • Decrease consumption of sugar drinks.

  • Drinking alcohol only in moderation, if at all. This means no more than two drinks a day for men and one drink a day for women. 

These same lifestyle changes are important if you have high blood pressure. The NHLBI and the AHA recommend that lifestyle changes be tried first. If these do not lower blood pressure enough, then you may need to take medication. Often, people need to take several different medications to drop their blood pressure to an acceptable level. Two types of medications appear to be more effective at lowering blood pressure among African-Americans. These are thiazide diuretics and long-acting calcium channel blockers. Treatment of other chronic conditions, such as type 2 diabetes, is also important.