Antibodies to cytomegalovirus, a virus that lies dormant in many adults, may be associated with the development of coronary artery disease, according to a study in the Nov. 14 issue of Circulation.
CMV infects more than half of American adults by age 40. While the virus causes no or mild symptoms in adults, it is dangerous to unborn babies, children, and individuals with suppressed immune systems. Because it stays alive in the body indefinitely, the body develops antibodies against the virus. Previous research has shown that infections by several common viruses, including herpes strains, H. pylori, pneumonia, and hepatitis, may increase some people's risk of heart disease, possibly as a result of inflammation. In men with CMV, the researchers say inflammation also seems to be the mediator between the virus and atherosclerosis.
In women, however, the current study suggests that the presence of CMV as indicated by a positive antibody test has a direct relationship to her susceptibility to atherosclerosis. Levels of CMV antibodies were highest in women with atherosclerosis. Researchers analyzed the body's responses to the viral infection in 151 men and 87 women. Angiograms were used to determine that 75 percent of the men and 52 percent of the women in the study had coronary artery disease. Participants had their blood tested for the presence of viral antibodies, levels of C-reactive protein, and the type of immune response to CMV. Researchers compared results from the three tests.
The study shows that in men, higher levels of viral antibodies were related to high levels of C-reactive protein and the prevalence of coronary artery disease. The researchers said CMV appears to contribute to coronary artery disease in men by predisposing their blood vessels to inflammation. Among the women, high levels of viral antibodies were directly associated with the prevalence of coronary artery disease, but not with high levels of C-reactive protein. Unlike the men, women did not have high levels of inflammation, but the viral antibodies were somehow affecting the blood vessels.