Genome study suggests blood vessels control blood pressure

Hypertension increases risk for heart disease and stroke, yet it is characterized by subtle symptoms that often go undetected. Lifestyle factors—such as diet and exercise—are thoughts to contribute to a patient’s risk of developing high blood pressure. But about half of the risk is determined by genes—and doctors aren’t entirely sure which ones.

Researchers at Johns Hopkins University may have just discovered a clue.

In a study published in the journal Nature Genetics, university scientists in collaboration with other groups discovered hints that biochemical signals controlling blood pressure may spring from within cells that line blood vessels themselves.

Prior to the new study, groups had identified some 90 sites in the genome as likely linked to blood pressure regulation. However, they still couldn’t explain all variations in blood pressure measurements. To identify more sites, researchers from 265 institutions worldwide banded together to perform the genome-wide association study.

Participants genomes were examined on microarrays. In total, researchers found 66 sites in the genome—17 of which were newly reported—that had statistically significant associations with blood pressure levels.

"Even taking all the known variants together, we explain only about 2 to 3 percent of the blood pressure variability between individuals,” Georg Ehret, MD, a research associate at Johns Hopkins, said.

He estimates there are "hundreds or thousands" of blood pressure-linked variants still to be found and says identifying them will require studies with even more participants. One benefit of gathering those missing genetic puzzle pieces would be to enable a genetic test to predict whether a person is likely to develop high blood pressure and, if so, allow for early intervention.

Surprisingly, the study found that many of the newly identified sites were located near genes active in cells inside of blood vessels. This suggest those cells are somehow directly involved in controlling blood pressure.