www.hivandhepatitis.com

Cardiovascular Disease Risk Is Higher for People with Hepatitis C

People with hepatitis C are at higher risk of dying from cardiovascular disease, having a stroke, or developing other cardiovascular problems than people with similar risk factors for heart disease who do not have hepatitis C, a meta-analysis of published studies has shown. The findings, published in the January 2016 edition of Gastroenterology, come from a meta-analysis of 22 epidemiological studies conducted in Italy.

[Produced in collaboration with Aidsmap.com]

Previous studies have produced inconsistent findings regarding the risk of cardiovascular disease in people with hepatitis C virus (HCV). These studies have suffered from insufficient numbers or weaknesses in design, limiting the strength of any conclusions.

Salvatore Petta and colleagues at the University of Palermo set out to pool data from published studies in order to produce more robust estimates of the risks of heart attack and stroke among people living with hepatitis C.

The researchers identified 22 studies which reported fully on the cardiovascular outcomes of people with hepatitis C in comparison to those of people without hepatitis C.

Their meta-analysis considered 3 outcomes:

• Cardiovascular mortality (death from any cardiovascular cause);
• Carotid atherosclerosis, as measured by carotid plaques (build-up of cholesterol, calcium, and fibrous tissue in the arteries, raising the risk of heart attack and stroke);
• Stroke or heart attack (cerebro-cardiovascular events).

Cardiovascular Mortality

Cardiovascular mortality was calculated from the results of 3 cohort studies which followed 68,365 people and observed 735 deaths. The pooled estimate showed a 65% increase in the risk of dying from a cardiovascular cause for people with hepatitis C (odds ratio 1.65; p=0.02). These studies were inconsistent in their recording of risk factors, so it was not possible to come up with a pooled estimate that controlled for the prevalence of risk factors.

Carotid Atherosclerosis

The prevalence of carotid atherosclerosis was calculated from 9 case-control studies, combining data from 9083 people, of whom 1979 had carotid artery plaques. The pooled estimate showed that people with hepatitis C were almost 2.5 times more likely to have a carotid plaque (odds ratio 2.27; p<0.01).

Hepatitis C had a much greater effect on the prevalence of carotid plaques when over 1 in 5 people in the study population smoked (odds ratio 2.66; p<0.001). The impact of HCV on carotid plaques was not statistically significant in populations in which smoking was less common, showing that smoking exacerbates any effect of hepatitis C on the development of cardiovascular disease, unsurprisingly.

Stroke, Heart Attack, and Other Cardiovascular Events

The impact of hepatitis C on the incidence of cardiovascular events, including stroke, was calculated from 8 studies, combining data from 390,602 people who experienced 18,388 events. Hepatitis C increased the risk of any event modestly, by 30% (odds ratio 1.30; p=0.002), and the effect was similar -- a 35% increase -- when the analysis was confined to stroke alone (odds ratio 1.30; p=0.05). The risk was significantly higher in studies where the background rate of diabetes was above 10%, the prevalence of high blood pressure was above 20%, or the average age of the study population was above 50 years.

The authors note that even after allowing for the well-established risk factors for heart disease -- diabetes, high blood pressure, and smoking -- the risk of death, cardiovascular disease, and carotid artery disease was still elevated in people with hepatitis C. Indeed, they describe the effect of hepatitis C on cardiovascular risk as "especially pronounced" in populations where diabetes, high blood pressure, or smoking are common.

The authors suggest that the metabolic abnormalities common in people with hepatitis C may provide one explanation for the increased risk, but they also point to recent evidence showing that hepatitis C promotes inflammation, which contributes to the development of cardiovascular disease.

1/21/16

Reference

S Petta, M Maida, FS Macaluso, et al. Hepatitis C Virus Infection Is Associated With Increased Cardiovascular Mortality: A Meta-Analysis of Observational Studies. Gastroenterology 150(1):145-155. January 2016.