People infected with the hepatitis C virus are not only at the risk for liver damage, they may also have a higher heart disease risk, a new study has claimed.
The findings emerged from a larger ongoing study of homosexual men, many of whom were infected with HIV and followed over time to track risk of infection and disease progression.
A subset of the participants had both HIV and hepatitis C, two infections that often occur together.
People infected with HIV are already known to have an elevated risk for heart disease. However, researchers emphasise their results offer strong evidence that hepatitis C can spark cardiovascular damage independent of HIV.
The research found that study participants chronically infected with hepatitis C were more likely to harbour abnormal fat-and-calcium plaques inside their arteries, a condition known as atherosclerosis and a common forerunner of heart attacks and strokes.
"We believe our findings are relevant to anyone infected with hepatitis C regardless of HIV status," said principal investigator Eric Seaberg, assistant professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health in US.
Researchers said that they do not know exactly how infection with the hepatitis C virus precipitates the growth of artery-clogging plaque, but that their evidence is strong enough to warrant vigilant monitoring for cardiac symptoms among people infected with the virus.
"People infected with hepatitis C are already followed regularly for signs of liver disease, but our findings suggest clinicians who care for them should also assess their overall cardiac risk profile regularly," said study author Wendy Post, professor at the Johns Hopkins University School of Medicine.
The study involved 994 men 40 to 70 years old without overt heart disease who were followed across several institutions in several US cities.
Of the 994, 613 were infected with HIV, 70 were infected with both viruses and 17 were only infected with hepatitis C.
Participants underwent cardiac CT scans to detect and measure the amount of fat and calcium deposits inside the vessels of their hearts.
Those with hepatitis C, regardless of HIV status, had 30 per cent more disease-fuelling calcified plaque in their arteries, the main driver of heart attack and stroke risk.
People infected with either HIV or hepatitis C, on average, had 42 per cent more non calcified fatty buildup, a type of plaque believed to confer the greatest cardiac risk.
Those who had higher levels of circulating hepatitis C virus in their blood were 50 per cent more likely to have clogged arteries, compared with men without hepatitis C.
Higher virus levels in the blood signal that the infection is not well controlled by drugs or the immune system.
Poorly controlled infection, the researchers said, may lead to more inflammation throughout the body, which can fuel blood vessel damage and thus contribute to heart disease.
The study was published in The Journal of Infectious Diseases.
