Hypertension a Silent Killer in Young African American Men

Study results published in the October 2008 issue of the American Journal of Physiology — Heart and Circulatory Physiology reveal that “young African American men have greater central [blood pressure] despite comparable brachial [blood pressure] when compared with young white men.” A potentially serious development in light of the authors’ assertions that “macrovascular and microvascular dysfunction manifesting as carotid hypertrophy, increased stiffness of central elastic arteries, heightened resistance artery constriction/blunted resistance artery dilation and greater arterial wave reflection is present at a young age in apparently healthy African American men and conventional brachial BP measurement does not reflect this vascular burden.”

An American Physiology Society news release stated that these findings suggest that hypertension “may be developing undetected in young African American men and that measuring central blood pressure may be a better means of detecting the problem as it develops.”

According to the release, the study enrolled 30 Caucasian and 25 African American men, with “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.” The researchers assessed the subjects’ vascular function using a variety of measures, including aortic blood pressure and stiffness, brachial blood pressure, carotid artery blood pressure, and carotid artery thickness and stiffness. The African American men had “similar brachial blood pressure, compared to the white men,” but demonstrated “significantly higher” central blood pressure and carotid artery pressure, as well as signs of early vascular damage that could lead to hypertension.

In the “Discussion” section of the article, the authors noted that central blood pressure (BP) “holds greater prognostic value than conventional brachial BP as central pressure more aptly reflects the load encountered by the heart (ie, ventricular-vascular coupling)… Thus, brachial blood pressure may neglect important information on cardiovascular burden and response to therapy in African American men.”

The authors also said that their results “support the notion that brachial BP does not reflect vascular burden, particularly in young healthy African American men and alterations in central pressure may precede alterations in brachial pressure.” Therefore, “measurement of central BP, vascular stiffness, and or intima-media thickness may fill a crucial void in current management of hypertension and related sequelae in African Americans,” said the authors.

Additional Resources

To watch a video interview with lead author Kevin S. Heffernan, PhD, visit the American Physiology Society’s Life Lines podcast website. Episode 15 features an interview with Dr. Heffernan (beginning at the 13:36 mark) discussing this study.