What's the Connection Between Ethnicity and High Blood Pressure?

Most Studies Show African-Americans Have a Higher Incidence of Hypertension

Doctor checking senior man's blood pressure. Credit: Terry Vine / Getty Images

Ethnic background plays an important, but as of yet not fully defined, role in the development of high blood pressure. Ethnicity is included in almost all lists of high blood pressure risk factors, and there are likely some underlying genetic components that have yet to be clearly identified. Still, the exact risk contributed by ethnicity is not agreed upon by major researchers, with some claiming a high level of risk and some claiming that ethnicity is a factor because it is linked to other variables that can affect outcome.

The question of possible genetic influence of different ethnic groups on developing high blood pressure is not simply an academic curiosity. Rather, these differences, if present, hold the promise for individualized treatment targeted to specific factors that may differ between ethnic groups. Such approaches could vastly alter the outcomes of high blood pressure treatment, and could improve the lives of millions of people. It is in this spirit that research continues on this topic.

Some Races At Higher Risk for High Blood Pressure

In nearly all of the studies on ethnicity as a risk factor for high blood pressure, two groups emerge as having risk that is much different than that for the population on average.

African-Americans, for example, consistently lead incidence profiles in high blood pressure studies, with about 36% of the population developing high blood pressure at some point. This is compared to about 20% in the Caucasian, Native American, and Hispanic populations.

 

Data from the National Health and Nutrition Examination Survey (NHANES) for the period 2003 to 2010 revealed that the proportion of Mexican-Americans and blacks with stage 1 and stage 2 hypertension was greater than for Caucasians.

On the other side of the equation, Asian populations, especially Asian Pacific Islanders (Hawaii, Japan, etc) consistently have the lowest demonstrated risk of developing high blood pressure, with an average lifetime risk of about 9.5% in men and 8.5% in women.

Significantly, these numbers hold relatively constant across many independent studies, suggesting that some genetic components may be at work, and that the elevated, or decreased, risk profiles genuinely are a factor of ethnic background.

A Closer Look at Ethnicity as a Risk Factor

Recently, a group of researchers has attempted to more closely examine the increased high blood pressure risk exhibited by African-American populations. To do so, they compared certain biological factors known to influence blood pressure in populations of African-Americans and native populations from the African continent. In doing so, they attempted to find a clear genetic rationale for the higher incidence of high blood pressure among African-Americans.

Their results, however, were very different than expected. They did find genetic similarities, which could possibly explain the increased incidence of high blood pressure in African-Americans, but they further discovered that the same genetic variant actually caused protection from high blood pressure in the native populations, a very curious and confusing result.

Similarly, studies have been done on various Asian populations and have found that the decreased overall incidence of high blood pressure tends to moderate when these people are placed into different cultural circumstances. For example, when native Vietnamese populations migrate to the United States, their risk of developing high blood pressure tends to approach that of Caucasians within a short time.

These results raise the question that it might be other, societal forces that contribute to differing rates of high blood pressure among various ethnic groups in the developed world. For example, minorities who occupy a lower place on the socioeconomic ladder and have poorer health care and less healthy lifestyles develop high blood pressure at increased rates. Data is still somewhat lacking on what happens to these ethnic groups at higher socioeconomic rungs.

Where It Stands

It is clear that certain ethnic groups are at increased risk for developing high blood pressure. It is not clear, however, whether this increased risk is a function of real genetic influences, or whether some social aspects and socioeconomic factors contribute more strongly than genetics.

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