Blood Pressure: Who's At Risk?

A report in Friday's edition of the journal Hypertension revealed that blood vessels in African Americans do not relax as much as those in whites during stressful situations. This is one reason to explain the higher incidence of high blood pressure among blacks.

On CBS'This Morning,Health Correspondent Dr. Emily Senay, answered some of the questions that this new study raises. She also warned that why stopping your blood pressure medication could potentially be dangerous and increase your risk of having a stroke.

The study conducted by Hypertension measured blood flow to the arm in African Americans and Caucasians who were solving complicated math problems.

Senay explained that while solving the math problems"more blood flow was produced in the arms of the Caucasian subjects than in the African American subjects. A chemical called nitric oxide causes vessels to open up, but blacks were found to be less sensitive to changes in the chemical."

Senay advised that everyone be screened for high blood pressure periodically. "If you're and African American, this is especially true for you," she said.

Hypertension is frequently referred to as a "silent killer" because it has few symptoms. Because the new study offers more information about the mechanics of the condition, it could help to "eventually devise a diagnostic test to identify those people who are at greatest risk for high blood pressure."

Those who already are taking blood pressure medication should be wary of stopping their medication unless a doctor advises them to do so.

This report comes in the wake of a recent warning to people with high blood pressure who take the medication Posicor.

Posicor was taken off the market June 8 because it did not interact well with other medications. The manufacturer now advises that patients should wait at least seven days after stopping the medication before taking another high blood pressure drug.

Senay cited another study from Hypertension that found that "people with high blood pressure who suddenly stop taking their medicines have a five to seven times greater risk of stroke than those that stay on their medication."

"Smokers and younger people with high blood pressure,Senay said, "are also at a higher risk for strokeÂ…So don't forget your medications."

Reported By CBS Health Correspondent Dr. Emily Senay