ICAAC 2003 coverage
New research offers clues to HIV/HCV co-infection
One study also finds diabetes link
Several studies presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) have shown how HIV patients who are co-infected with hepatitis C are at greater risk for medical complications, including diabetes.
Investigators at the University of Pittsburgh and the VA Pittsburgh Healthcare System found that HIV infection may increase the risk of diabetes mellitus associated with hepatitis C infection, age, and minority race.1
Another study, which was presented at ICAAC by researchers at the Ottawa Hospital and Uni-versity of Ottawa in Ontario, Canada, found that it remains difficult to achieve desired hepatitis C virological results (from HCV drugs) among HIV/HCV co-infected patients even when the patients have been successful with HIV antiretroviral treatment.2
"Some people have reported an increased association of diabetes with HIV/hepatitis C co-infection," says Adeel A. Butt, MD, assistant professor of medicine at the University of Pittsburgh and director of ID-HIV clinics at the VA Pittsburgh Healthcare System. Also, research has suggested that hepatitis C patients have a three- or fourfold increased risk of being diagnosed with diabetes, he notes.
"So we wanted to find out if HIV on top of hepatitis C is associated with an even higher risk of diabetes," Butt explains.
Investigators analyzed data from 1992 to 2001 of more than 33,000 HIV-infected veterans and more than 38,000 veterans who were HIV negative.1
"Since it would have been difficult to differentiate the effects from highly active antiretroviral treatment (HAART) in that database, we limited the study to those who were in care after 1996," he says. They found that people who were co-infected with HIV and HCV had a 19.3% prevalence of diabetes, while those who were HIV-positive and HCV-negative had a 13.7% prevalence of diabetes, Butt adds. "That was not adjusted for age or race or other factors."
After conducting a multivariate analysis that takes into consideration the development of diabetes as a risk factor, investigators found that when HIV-positive patients were compared with HIV-negative patients, the HIV-positive group that also had HCV infection had a 64% greater chance of being diagnosed with diabetes, and that data were adjusting for age, race, gender, and history of drug and alcohol use, Butt says.
"The other major finding is that both age and minority race were very significantly associated with diabetes in the HIV-positive group, but not that much in the HIV-negative group," Butt explains.
For example, for every 10 years of age in the HIV-positive group, there was a 64% increase in the risk of diabetes, while in the HIV-negative group the difference between age groups was not significantly different, he says. Also, among African-Americans who were HIV-positive, there was a 28% increased risk of diabetes, and HIV- positive Hispanics had a 35% increase in diabetes risk, while HIV-negative people of both ethnicity’s had not significant difference in risk, Butt adds.
"In the HAART era, HIV infection appears to be associated with the high risk of diabetes, and this risk is increased by hepatitis C co-infection, increasing age, and minority race in this group," he states.
These findings suggest that HIV clinicians diligently screen patients for diabetes, particularly when there is a hepatitis C co-infection, increasing age, and minority race, Butt adds.
Canadian researchers have examined the impact of HIV on hepatitis C infection among a small cohort of patients who had been infected with both viruses for about two decades.
"What I wanted to do was demonstrate the negative impact HIV has on hepatitis C infection and indicate why it’s important we talk about treatment with this population," says Curtis L. Cooper, MD, FRCPC, assistant professor at the University of Ottawa in the division of infectious diseases.
"Our data indicate that patients who are co-infected are more likely to have high levels of liver fibrosis compared with those who are just hepatitis C-infected," he says.
Co-infected patients had a significantly higher rate of advanced stages of liver scarring than did patients who were only HCV-infected, and the liver enzymes in the co-infected population were 1.5 to two times higher than the population only infected with HCV, according to Cooper.
"Excess alcohol consumption was the same in both groups — 25%," he adds. "We found that the things that predicted rapid fibrosis rate included HIV infection, not being on HAART, male sex, and high liver enzymes."
Cooper and co-investigators also examined the effectiveness of hepatitis C therapy in a co-infected population, particularly looking at patients who had started to receive ribavirin. There were 11 co-infected patients who had initiated use of ribavirin and interferon for their hepatitis C infection, he says.
"We saw that the sustained virologic response rates were 20% in co-infected and 40% in HCV mono-infected populations," Cooper explains. "So what this shows us is how HIV really impairs people’s ability to get sustained virologic responses [to HCV medication]."
This result was despite the fact that of the patients who were treated with HAART for their HIV infection, 80% had achieved an HIV virological suppression of at least below 500 copies, he adds.
"So the point is that patients who start HAART, a large portion of them are able to stay on HAART and get good virologic response," Cooper says. "By contrast, those on interferon-based therapies for hepatitis C infection rarely get sustained virologic response rates."
The study also found that HIV patients who were started on HAART were far less likely to stay on their antiretroviral regimen if they were consuming excess alcohol at the time of initiating treatment or if they had a history of injection drug use, he notes.
The message to clinicians is to first get their HIV/HCV co-infected patients to reduce alcohol consumption and drug use, then to help them achieve virologic goals on HAART, and then to treat their hepatitis C, Cooper says.
"In most cases, the biggest bang for your buck is to get them on HAART and cut alcohol consumption," he states. "So a key point is that we should be putting our efforts into alcohol cessation as much as we are into antiretrovirals and interferon therapies."
In further HIV/HCV research presented at ICAAC investigators found that HIV/HCV co-infected patients appeared to have a lower virological response rate when treated with HCV drugs and that patients who were unsuccessful early on with peginterferon alfa-2a monotherapy received no benefit from additional treatment with ribavirin.3
References
1. Butt AA, Fultz SL, Skanderson M, et al. Understanding the association between DM and HIV and HCV infections in the era of HAART. Presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy. Chicago; Sept. 14-17, 2003. H-1715.
2. Cooper CL, LaRoche A, Kane M, et al. Evaluation of the benefits of HAART in HIV-HCV co-infected subjects. Presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy. Chicago; Sept. 14-17, 2003. H-826.
3. Khalili M, Hoffman-Terry M, Fisher E, et al. Efficacy and safety of peginterferon Alfa-2a (40 KD) treatment of patients with HIV/HCV: Results of a multicenter trial. Presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy. Chicago; Sept. 14-17, 2003. V-1727.
Several studies presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) have shown how HIV patients who are co-infected with hepatitis C are at greater risk for medical complications, including diabetes.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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