Hypertension in African Americans
Black Americans Suffer From Hypertensive Disorder More Than Whites
Compared to the non-African American population, Blacks experience higher rates of hypertension and hypertensive disorders for several reasons.
Health awareness campaigns have revealed how many African Americans—especially Black women—suffer and die from hypertension and associated hypertensive disorders at a much higher rate than the general population. But less well known and understood are two equally significant findings:
- The physiology of hypertension among Black adults is apparently in some ways different from that of the Caucasian population
- Some anti-hypertensive drugs are less therapeutic among Blacks than Whites.
The rates of hypertension among Hispanics, Native Americans and Caucasians range from 24 - 27%, while the American Heart Association reports that the disease afflicts more than 40% of African Americans, a rate among the highest in the world. Hypertension may account for as many as 40% of all African American deaths, twice the rate of such deaths among Whites. Compared to Caucasians, African Americans develop hypertension earlier in life, have higher rates of fatal stroke and heart disease, and four times the rate of end-stage kidney disease.
Reasons for hypertensive disorders in African Americans
Research suggests that African Americans may be unequally vulnerable to hypertensive disorders in the following areas:
1. Salt Sensitivity. Half of all people with hypertension retain salt and water, a condition called salt sensitivity. African-Americans, along with the elderly and people with diabetes, are more likely to be salt-sensitive. Salt sensitive individuals have an impaired ability to excrete ingested salt, leading to an expansion of water volume in the blood vessels, and accompanying elevated blood pressure. The culprit is a natural protein called angiotensin II that regulates salt and water balances and narrows the blood vessels forcing the heart to work harder.
Legitimate researchers cannot entirely explain why some individuals are more salt sensitive than others. Nevertheless, a pseudoscientific theory has circulated that purports to explain this condition among Blacks. During the slave trade, the theory goes, Africans were deprived of water and endured vomiting and dysentery during their long, grueling voyages to the Americas. Only slaves with a predisposition to salt retention survived, and loaded the Black gene pool with descendants who similarly hoard their salt reserves. This “theory” has been thoroughly discredited.
2. Nitric oxide. Blacks also manifest lower levels of nitric oxide, a gas produced in the body that prevents hardening of the arteries and enables the blood vessels to remain relaxed, open and flexible. Low levels of nitric oxide have been observed in people with high blood pressure, particularly among African-Americans, and may be an important factor in cardiovascular disease and hypertension with no known cause, called essential hypertension.
3. Depression. Mounting evidence suggests that depression contributes to destructive behaviors, such as weight gain, smoking, or alcohol abuse, all of which have physiological effects that impair the heart. In one study, those who scored highest on a depression test had about twice the risk of high blood pressure as those with the lowest score. This link was particularly strong in African Americans. Depression was the strongest risk factor in this group.
Sources
FDA News
Medscape Medscape Today, Medscape Family Medicine/Primary Care.
Morehouse School of Medicine, Emory University, and Association of Black Cardiologists, Inc.
Cardiovascular Research Institute, Morehouse School of Medicine
MedicineNet.com
Hypertension Online
Ohio University, Research News
Los Angeles Times
American Heart Assn
Univ. Cincinnati, Case Western Reserve Univ., The Ohio State University
Archives of Internal Medicine
Journal of the American Academy of General Physicians
New York Times Health Guide
Ion Channel Media Group Ltd./National Center for Biotechnology Information
Mayo Clinic
