Girl’s Blood Pressure May Predict Family Heart Disease, Doctors Say

How much an 11-year-old girl’s blood pressure goes up during exercise can probably predict whether she or a member of her family will die of heart disease before reaching age 55, a team of Medical College of Virginia doctors reported Wednesday.

In a paper presented at the American Heart Assn. convention in Anaheim, Dr. Joann Bodurtha and Dr. Richard Schieken said they had found a connection between blood pressure and exercise as a childhood predictor of heart attacks by studying 300 pairs of 11-year-old twins and their parents in the last four years.

Bodurtha, a pediatric geneticist, and Schieken, a pediatric cardiologist, said they chose twins for their study to keep environmental influences from skewing their results.

Before the stationary-bicycle exercise test began, the children and their parents--from the Richmond, Va., area--were questioned to determine whether close relatives, such as parents, brothers, sisters or children, had died of heart disease before age 55, Bodurtha said.

Then, the twins and their parents were observed as they rode on stationary bicycles, pedaling with increasing resistance or workloads, Bodurtha said.

‘Striking’ Comparison

“What we found when we compared blood pressures and family medical histories was striking,” Bodurtha said. “Blood pressures taken while the children and their parents were at rest had no relationship to a family history of death from heart attack by age 55.”

But the blood pressures taken during the five bicycle workloads showed a direct relationship between high blood pressure and a family history of heart disease. Mothers who registered high blood pressure levels while bicycling had family histories of heart attacks. So did more than 200 of their female twin daughters.

Yet the changes in blood pressure were “not related to family history in male twins or their fathers,” Bodurtha said. “The reason for this sex difference is not clear. But it could be due to hormonal or life style differences.”

Blood pressure changes, Bodurtha said, are the normal body response to exercise or psychological stress. “Reaction to these stresses is greater in some individuals than in others,” Bodurtha said.

Early Warning Signs

But Bodurtha said that the unusually high blood pressure readings recorded for girls with family histories of heart disease makes her believe that heart disease--or its early warning signs--may already be present in these girls, even though they are just 11.

The researchers were not sure why these blood pressure readings provide such a good clues to heart disease in both the girls and their families. One possibility, Bodurtha said, is that high blood pressure readings when these girls overreact to stress may either start, or accelerate, the aging process that leads to blocked arteries and heart attacks.

“This could lead to premature cardiovascular death, or it could be that the same genes that control blood pressure reactivity in females may also control the processes that lead to premature cardiovascular death in their close relatives, both male and female,” Bodurtha said.

While twins were studied, Bodurtha said the findings can be applied to the general population because the study group included almost as many non-identical as identical twins. Identical twins develop from the same fertilized egg, whereas non-identical, or fraternal, twins develop from different fertilized eggs, as do regular brothers and sisters.

The study’s findings, Bodurtha said, can be used for preventive medicine, not only by the young girls and their families but also by others with possible heart problems.

“Most cardiologists are used to testing patients on the stationary bicycle test, a simple progressive exercise,” Bodurtha said. “When patients are found to have highly reactive blood pressures, they can be counseled about proper diet, avoidance of smoking, stress and other factors linked with early death from cardiovascular disease.

“In this way,” Bodurtha said, “people can tip the balance away from their genes and toward a more healthy life style.”