Norwegian researchers using a “virtual human” to explore reasons for high blood pressure, discovered stiff arteries alone are enough to cause high blood pressure.

High blood pressure affects more than one billion people across the globe, but the cause of 90 percent of the cases of this highly age-related condition couldn’t be explained by physicians until now.

Klas Pettersen, a researcher at the Norwegian University of Life Sciences and first author of the study, and colleagues developed a computer model of a “virtual human,” which suggests that stiff arteries are a major factor behind high blood pressure.

When blood flows down the aorta from the heart, “baroreceptors” sense the pressure in the artery, and stretch the walls to accommodate for the flow. Signals are then sent to the nervous system. When blood pressure gets too high, stronger signals are sent to allow the body to lower the pressure. However, if the aorta is too stiff, the stretching of the walls is not as sensitive as it should be to measure blood pressure. In this case, the baroreceptors do not send a signal strong enough to give the message to the nervous system to lower the blood pressure.

With existing experimental data, the researchers were able to determine how the stiffening of the aorta can cause the baroreceptors to misdirect the nervous system about blood pressure, and therefore prevent the system from lowering blood pressure.

“Our results suggest that arterial stiffness represents a major therapeutic target. This is contrary to existing models, which typically explain high blood pressure in terms of defective kidney function,” said Pettersen in a statement.

The research is published in PLOS Computational Biology.