HIV-positive individuals who are coinfected with hepatitis C virus are significantly less likely to have elevated cholesterol levels than patients who are HIV-monoinfected, according to a study published in the November edition of HIV Medicine.
Liver disease, often caused by hepatitis C virus, and cardiovascular illness, due to some anti-HIV drugs, are emerging as major causes of illness and death in HIV-positive individuals and investigators from Texas wished to establish the effect of hepatitis C infection on the lipid profiles of HIV-positive patients.
They therefore performed a retrospective analysis of the records of 359 HIV-positive patients (25% of whom were coinfected with hepatitis C virus) and 112 hepatitis C monoinfected individuals to determine the effect of hepatitis C infection on total triglycerides, total cholesterol, LDL ("bad") cholesterol and HDL ("good") cholesterol. The patients were receiving their HIV or hepatitis C care from the US Department of Veterans’ Affairs and were seen between 2003 and 2004.
Data were obtained on all patients’ demographic characteristics. Information on HIV-positive patients' type and duration of antiretroviral therapy was also extracted from medical records, as were data regarding CD4 cell count and viral load. The investigators also noted if HIV-positive patients had been diagnosed with body fat changes (lipodystrophy).
The median age of the study population was 51 years, 98% were male, and 53% were white.
Amongst the HIV-positive patients, infection with hepatitis C was associated with a significantly reduced risk of increased total cholesterol (p
After controlling for the use of anti-HIV therapy, gender and race, coinfection with hepatitis C remained significantly associated a reduced risk of increased cholesterol, but not elevated triglycerides.
Further analysis was performed to take account of the use of lipid lowering therapy. This too showed that coinfected patients were less likely to have dyslipidaemia or to require lipid lowering therapy (p = 0.002).
The investigators then compared rate of lipodystrophy between patients who had only HIV and those who were also infected with hepatitis C. HIV-monoinfected patients had a significantly higher rate of lipodystrophy (28%) than coinfected patients (17%, p = 0.015). However, this difference disappeared in multivariate analysis.
Comparisons were then made between the lipid profiles of the HIV/hepatitis C coinfected patients and the HIV-negative, but hepatitis C-infected patients included in the study. There was no significant difference in the proportion of coinfected and hepatitis C-monoinfected patients with increased cholesterol. But significantly more of the coinfected patients had elevated triglycerides (48% versus 16% of hepatitis C monoinfected, p
A set of multivariate analyses were then performed by the investigators. These showed that being hepatitis C-negative (p = 0.019), older age (p = 0.041) and white race (p = 0.001) all predicted dyslipidaemia and the use of lipid lowering drugs. Predictors of lower rates of elevated cholesterol were infection with hepatitis C virus (p = 0.01) and shorter duration of treatment with a protease inhibitor (p = 0.03). White race was the only factor associated with an increased risk of elevated triglycerides (p
The investigators believe that their findings “significantly strengthen the hypothesis of an apparent protective effect of hepatitis C virus infection on the development of dyslipidaemia.”
They draw three conclusions:
- Hepatitis C infection is associated with lower rates of dyslipidaemia among HIV-infected patients;
- Hepatitis C infection does not independently affect the risk of lipodystrophy in multivariate analysis, and
- Black race and hepatitis C are associated with lower rates of dyslipidaemia among HIV-positive patients.
Although the patient population was larger than in previous studies looking at the link between HIV/hepatitis C coinfection and lipids, the investigators note that there is still a need for larger, prospective studies to confirm their findings.
They speculate that hepatitis C might occupy LDL receptors on cells, preventing the entry of LDL cholesterol. However, they think that a more plausible explanation could be that hepatitis interferes in the dysregulation of the lipid metabolism caused by HIV.
Bedimo R et al. Lipid abnormalities in HIV/hepatitis C virus-coinfected patients. HIV Med 7: 530 – 536, 2006.