A 54-year study has solidified the link between parents’ high blood pressure and the chances their children will develop this significant risk factor for cardiovascular disease.

A family history of hypertension is well-established as a warning sign — researchers estimate that 35 percent to 65 percent of high blood pressure is inherited.

However, “there are a couple of unique features about our study,” said Nae-Yuh Wang, an assistant professor of medicine at Johns Hopkins University and lead author of a report in the March 24 issue of the Archives of Internal Medicine.

“One is that we have an incredible amount of data,” Wang said. His group followed 1,160 men in a study that started in 1947, when the participants were medical students, and made annual measurements of their blood pressure over the next five decades.

“And we did not just recall the usual data,” Wang added. “We were able to classify the potential risk a lot better.”

At the start, 264 participants reported at least one parent with high blood pressure, while only 20 had two parents with high blood pressure. By the end of the study, 583 new cases of parental hypertension were diagnosed, so that 701 (60 percent) of the group had at least one parent with high blood pressure, and 166 (14 percent) had two.

The age at which high blood pressure was detected in the parents was important, Wang said.

“What we found was that if parents have hypertension early, their children have a significantly higher risk of developing hypertension at an early age,” he said. “If the parents develop hypertension at the age of 55 or earlier, the lifetime risk for the children is seven-fold higher than normal.”

The lesson for young adults is that they should pay attention to their parents’ blood pressure, Wang said. “They should tell themselves that if their parents develop high blood pressure early, they should pay more attention to their health,” he noted.

The finding reinforces the standing advice to consider family history when assessing the risk of high blood pressure, said Dr. Barry Davis, a professor of biostatistics at the Coordinating Center for Clinical Trials at the University of Texas School of Public Health in Houston.

“Everyone should have their blood pressure checked early,” he said. “If they have a family history of hypertension I would check it more often, and at an earlier age.”

While high blood pressure has many potential causes, “I would expect it to have a genetic factor,” Davis said. “Potentially many genes are involved in the regulation of blood pressure. We’re trying to find out what they are and how they operate.”

Regardless of the exact cause, medication, careful attention to diet and exercise can help keep blood pressure under control, Wang and Davis said.

Another study in the same issue of the journal looked at 48 medical papers on the effect of diet and medication on high blood pressure. The study, conducted by researchers at the Medical University of Graz in Austria, concluded that a diet that reduced weight by about 9 pounds would bring blood pressure down 6 points, and that use of the weight-loss medication Orlistat also reduced blood pressure.

(Source: Nae-Yuh Wang, Ph.D., assistant professor, medicine, Johns Hopkins University, Baltimore; Barry Davis, M.D., professor and director, biostatistics, University of Texas School of Public Health, Houston; March 24, 2008, Archives of Internal Medicine)