Insulin Resistance Correlates With HCV Load and SVR in HCV/HIV-Coinfected

50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), September 12-15, 2010, Boston
Mark Mascolini

A study of 107 people coinfected with HCV and HIV found a strong correlation between insulin resistance and both HCV load and sustained virologic response (SVR) to pegylated interferon (PegIFN) alfa2a plus ribavirin [1]. Researchers from the University of Brescia believe their findings help explain the reduced response to PegIFN/ribavirin in coinfected people with insulin resistance.

The study involved 107 HCV/HIV-coinfected people who started PegIFN (180 mcg/week) and ribavirin (1000 to 1200 mg/day) since January 2005. The investigators used the HOMA-IR method to calculate insulin resistance. Study participants had a median age of 43 years (interquartile range [IQR] 40 to 46) and a median HCV load of 5.7 log IU/mL (IQR 4.9 to 6.0). Sixty people (56%) had METAVIR-determined advanced liver fibrosis.

Forty-seven study participants (44%) had a sustained virologic response. Multivariate analysis identified three factors that independently predicted SVR:

-- HCV genotype 1 or 4 lowered the chance of SVR 90% (adjusted odds ratio [AOR] 0.1, 95% confidence interval [CI] 0.04 of 0.3, P < 0.01).

-- HCV RNA below 400,000 IU/mL tripled the chance of SVR (AOR 3.08, 95% CI 1.08 to 8.6, P = 0.03).

-- HOMA-IR below 3 more than tripled chances of SVR (AOR 3.5, 95% CI 1.2 to 10.1, P < 0.001).

Factors that did not independently affect chances of SVR in this analysis included advanced liver fibrosis, HIV load below 50 copies, total cholesterol, low-density lipoprotein cholesterol, and triglycerides.

Median HOMA-IR score was 2.9 in people with an HCV load below 6 log and 3.3 in those with a higher load, a significant difference (P = 0.006). Linear regression analysis confirmed a strong correlation between HOMA-IR and HCV load at an r(2) value 0.93 (P < 0.0001). HCV genotype 1 or 4 correlated with HCV load more strongly than genotype 2 or 3: r(2) 0.9 (P < 0.0001) versus 0.6 (P < 0.0006).

Earlier work by these same investigators found that insulin resistance impaired rapid virologic response to PegIFN/ribavirin in coinfected people [2].

References

1. Nasta P, Gatti F, Borgh F, et al. Insulin resistance is associated with hepatitis C viremia and reduces the success of peginterferon alfa2a plus ribavirin in HIV/HCV co-infected patients. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). September 12-15, 2010. Boston. Abstract H-1673.

2. Nasta P, Gatti F, Puoti M, et al. Insulin resistance impairs rapid virologic response in HIV/hepatitis C virus coinfected patients on peginterferon-alfa-2a. AIDS. 2008;22:857-861.

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