Health Discovery: Common Virus May Promote High Blood Pressure

Summary:
• Mice with the virus were more likely to develop high blood pressure, atherosclerosis
• More than 50% of all people 40+ have the virus
• The virus, otherwise usually harmless, is tough to eradicate

A high-fat diet, a sedentary lifestyle, smoking and an unlucky genetic inheritance are key factors in heart disease. Might a little-noticed yet ubiquitous virus also play a role?

Researchers from Harvard-affiliated Beth Israel Deaconess Medical Center in Boston have produced the latest findings suggesting that cytomegalovirus (CMV), a member of the herpesvirus family that’s found in more than half of people over 40 and is usually harmless, can promote high blood pressure and atherosclerosis. And they’ve shed new light on how this might occur.

Published May 15 in the journal PLoS Pathogens, the study found that CMV-infected mice were more likely than control mice to develop high blood pressure. Infected mice that were also fed a high-cholesterol diet additionally showed increased signs of atherosclerosis, a fatty buildup inside the arteries. Using cell cultures, the researchers then demonstrated that the virus seemed to promote inflammation and constriction of the blood vessels, important factors in cardiovascular disease.

Scientists have been investigating a possible link between herpesviruses and heart disease since experiments in the late 1970s found that an avian herpesvirus produced visible hardening of the arteries in chickens. The newly published findings are “interesting, in that they potentially show a direct effect of the virus” on specific components related to hypertension, says Carlos Ferrario, M.D., director of the Hypertension and Vascular Research Center at Wake Forest University.

But there’s still no direct evidence that the extremely widespread virus actually produces these effects in people, says Ferrario. That’s a major hurdle to developing any new therapies based on the theory. Another problem: Herpesviruses are notoriously tough to eradicate.

Katharine Greider writes about medical issues and health policy.