A recent animal study may point to a hidden cause of high blood pressure in humans.
When mice were infected with a virus known as the cytomegalovirus, or CMV, they were more likely to develop high blood pressure as well as atherosclerosis, or hardening of the arteries.
This means that we may be able to find a new way to prevent and even treat high blood pressure, by using a vaccine or antiviral medications.
CMV is a very common virus. In fact, between 60 and 99 percent of all adults around the world are infected with CMV. In most adults, the virus causes no problems. In pregnant women, however, a CMV infection can cause serious birth defects.
The first evidence that a CMV infection could cause problems with blood vessels was when CMV positive heart transplant recipients were found to be more likely to have blockages in the arteries in their heart.
The new study was a cooperative effort from specialists in cardiology, pathology, and virology. The study used four groups of mice, two of which were fed a standard diet, two of which were fed a high cholesterol diet.
Then one of each of the diet groups was infected with CMV. This allowed researchers to compare the effects of a CMV infection in conjunction with both a standard diet and a high cholesterol diet.
At six weeks, mice that had been infected with CMV showed increased blood pressure. In addition, mice that had been infected with CMV and that had been given the high cholesterol diet also developed hardening of the arteries.
CMV seems to increase the activity of an enzyme called renin, and a protein called angiotensis 11, both of which are known to be associated with high blood pressure.
About 98 percent of the time, doctors aren’t sure why a person has high blood pressure. Figuring out what causes high blood pressure can make it easier to prevent and treat the disease.
While researchers do not believe that all cases of high blood pressure are the result of CMV, they do believe that it plays a clear role in high blood pressure. Whether or not a patient smokes, how active a patient is, and what kind of diet a patient eats can also make a difference.
Currently, efforts at developing a vaccine to protect against CMV have been targeted toward pregnant women. The leading causes of deafness and mental retardation in children is believed to be a CMV infection during pregnancy.
As the role of CMV in high blood pressure becomes more clear, that search for a vaccine will expand to the greater population.