Insight on High Blood Pressure in African-Americans
By Babalola Faseru MD, MPH
Hypertension or high blood pressure is a silent killer. Many people with this condition go around without any signs or symptoms of illness. More than one in three African-Americans have hypertension. In fact, according to the American Heart Association, African-Americans have one of the highest rates of high blood pressure in the world. However, most of them do not know it; and it is a major reason why African-Americans die prematurely.
Blood pressure is the measure of the force with which blood flows in the blood vessels (arteries and veins) within the body. Normal blood pressure is considered to be 120/80 mmHg or lower. When pressure is high within the blood vessels, the heart does extra work to pump blood round the body. As time goes on, an overworked heart will not function properly.
Blood supply to vital organs will be lessened and those organs will not function well:
- Heart — fatal heart attack
- Brain — stroke
- Kidneys — hypertensive kidney disease
- Eyes — damaged vision
Hypertension affects all the organs in the body directly or indirectly.
There are two types of hypertension: primary and secondary. In primary hypertension, also called essential hypertension, the cause is not known and the diagnoses are made after reviewing and disproving all other causes. About 90 to 95 percent of high blood pressure cases are essential hypertension. Secondary hypertension occurs as a result of another condition such as narrowing of the renal arteries (in the kidneys), chronic kidney failure, stress, thyroid disease, narrowing of the aorta (main arteries), pregnancy, disease of the adrenal glands (located above each kidney) etc.
High blood pressure is not a simple disease; it has many causes and effects. We’ve touched upon the effects it has on the body. The causes are just as varied. There are genetic (inherited traits that are not easy to change) and behavioral (living conditions that may be more easy to change) factors.
Possible Causes for High Blood Pressure
Genetics may play a part. Historians reported that many African-Americans died during the Atlantic slave trade because they were deprived of salt. Those who survived and made it to Europe and the United States were thought to be able to retain salt. They in turn passed this trait to their children and grandchildren. Now with the current American diet that is heavy in sodium, a trait that was helpful is now harmful. This is described as the “slavery hypertension” hypothesis. Although this theory is controversial, there is no doubt that hypertension may be inherited in 30 to 60 percent of cases.
Another reason may be a chemical imbalance in the body. Some researchers have reported that African-Americans may have low levels of a substance which keeps the vessels flexible and open (nitric oxide) and high levels of another substance which narrows blood vessels (endothelin-1). Also, some African-Americans do not respond very well to a substance that is important for the body to regulate salt and water (Angiotensin II).
Living conditions have their role in creating stress. Hypertension has been described as a disease of urbanization: occurring more often in areas where there are fewer opportunities and greater challenges. Lack of education, unemployment, job stress, low income, anxiety and depression, substance abuse, and lack of health insurance have been associated with hypertension. Other factors such as neighborhood crime (keeps people from outdoor physical activity), lack of neighborhood walk ways, no regular source of medical care, defective criminal justice system and imprisonment increase stress, which results in increased blood pressure. Discrimination, racism and limited access to quality medical care have also been linked to increased cardiovascular disease.
Young, urban, African-American men have a particularly higher risk of hypertension as a result of these influencing factors.
Because hypertension is a complex disease affecting every organ, other diseases such as obesity, diabetes and kidney disease can lead to high blood pressure.
Hypertension is especially dangerous for African-Americans: as a group, more African-Americans have high blood pressure than other racial groups. According to the American Heart Association, African-Americans develop hypertension earlier in life, are six times more likely to develop kidney disease and twice more likely to die of heart disease or stroke compared to Caucasian Americans.
Once a person has hypertension, it becomes a lifelong struggle to keep it under control. Diet, exercise, medication and stress reduction are vital in controlling high blood pressure. The best place to start is with a visit to your health care provider to check your blood pressure. By consistently monitoring your blood pressure and following your health care provider’s plan of treatment, you can slow the damages to your body that uncontrolled hypertension causes and improve the quality of your life.
Additional resources you can locate online are:
Babalola Faseru MD, MPH, is a Research Assistant Professor, Department of Preventive Medicine and Public Health, University of Kansas Medical Center, Kansas City, KS
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