A study says there are signs that young and seemingly healthy black men develop high blood pressure earlier than white men, though it develops in a way that can be hard to detect.

The black men had higher central blood pressure in the aorta near the heart. But there was no difference in the brachial blood pressure, which is measured in the arm.

Researchers said in a news release that the findings suggest that hypertension develops silently in black men.

"Central blood pressure holds greater prognostic value than conventional brachial blood pressure, as central pressure more aptly reflects the load encountered by the heart," the University of Illinois, Urbana-Champaign, authors said in a news release.

They found that the black men had stiffer and thicker blood vessels, which can result in choppy blood flow at higher pressures, which can damage organs.

The study included 55 young men, 30 white and 25 black. Most were university seniors and the average age was 23. The groups were matched for characteristics such as heart rate, fitness, BMI, body fat and cholesterol levels.

These results do not shed light on why this happens to young and fit black men, said author Kevin S. Heffernan said. There may be environmental differences, such as differences in diet, which were not examined as part of this study, he said.

The study appears online in the American Journal of Physiology-Heart and Circulatory Physiology.