Hypertension Found to Develop Early and Silently in African-American Men

by VR Sreeraman on Nov 18 2008 5:30 PM

Scientists have found evidence that African-American men are developing hypertension early, and that too without any significant signs.

University of Illinois researchers have found that young and healthy African-American men have higher central blood pressure, and their blood vessels are stiffer compared to their white counterparts.

The researchers say that this finding is indicative of early Hypertension among Afro-Americans.

In a study, the researchers found that central blood pressure (the pressure in the aorta, near the heart) was higher in the African-American men, but no difference was seen in brachial blood pressure (measured on the arm) between the two groups.

Based on their observations, the researchers came to the conclusion that hypertension (high blood pressure) might be developing undetected in young African-American men.

They also said that measuring central blood pressure could turn out to be a better means of detecting the problem as it develops.

"Central blood pressure holds greater prognostic value than conventional brachial blood pressure as central pressure more aptly reflects the load encountered by the heart. Thus, brachial blood pressure may neglect important information on cardiovascular burden and response to therapy in African-American men," explained the authors.

Hypertension is known as the silent killer as it can develop without the individual knowing it. It may even lead to heart disease, stroke, congestive heart failure, and kidney disease.

The study included 55 young men, 30 white and 25 African-American, with the majority being university seniors. There were no differences between the groups on a variety of measures, including heart rate, cardiorespiratory fitness, body mass index, body fat, blood lipids and glucose levels.

Vascular function of the participants was measured in many ways, which included aortic blood pressure and stiffness, brachial blood pressure, carotid artery blood pressure, carotid artery thickness and stiffness.

While the brachial blood pressure was found to be similar in both African-American and white men, the Afro-Americans still scored higher in central blood pressure.

Carotid artery pressure was also higher in Afro-Americans. The African-American men, unlike the white men, also showed signs of early vascular damage that could lead to hypertension.

They also had stiffer arteries, which are associated with high blood pressure.

Also the change in diameter of the arteries when the heart beats was also less in the case of Afro-Americans. This is another measure of vascular stiffness. A healthy artery is more elastic will change in size as the blood flows through with each beat of the heart.

"Although having a similar cardiovascular risk factor profile as young white men, diffuse macrovascular and microvascular dysfunction is present at a young age in apparently healthy African American men," the authors wrote. "Values seen are comparable to values often reported in older individuals or individuals with more advanced hypertensive disease," said the authors.

Kevin S. Heffernan, lead author of the study, said that the results do not reveal much behind the reason why this happens to young and fit African-American men.

He said that there may be environmental differences, such as differences in diet, which were not examined as part of this study

The study, "Racial differences in central blood pressure and vascular function in young men" appeared online in the American Journal of Physiology-Heart and Circulatory Physiology.