Insulin Resistance is Not a Significant Predictor of Sustained Response to Interferon-based Therapy in HIV-HCV Coinfected Patients

By Liz Highleyman

The relationship between insulin resistance and hepatitis C virus (HCV) infection and its treatment are not fully understood. Some studies in HCV monoinfected individuals have shown that insulin resistance is associated with accelerated liver fibrosis progression and poorer response to interferon-based therapy, but others have not seen these effects. There has been less extensive research with HIV-HCV coinfected patients.

Nicolas Merchante and colleagues from several centers in Spain looked at the relationship between baseline insulin resistance and response to pegylated interferon plus ribavirin in 155 consecutive HIV-HCV coinfected patients. Merchante's group previously demonstrated that insulin resistance was not linked to fibrosis progression in coinfected individuals.

The main outcome variable was SVR, defined as undetectable HCV RNA 24 weeks after completion of treatment. Insulin resistance was determined using the Homeostatic Model Assessment (HOMA) method, with a threshold of 4.

Results

Overall, 55 of 155 patients (36%) achieved SVR.

38% of patients with HOMA scores below 4 achieve a sustained response compared with 29% of those with higher HOMA scores, not a statistically significant difference (P = 0.27).

Among participants with HCV genotypes 1 or 4, SVR rates were also similar for those with HOMA scores above and below 4 (27% vs 24%; P = 0.8).

In a multivariate analysis, HCV genotype 3, baseline HCV viral load below 600,000 IU/mL, and baseline LDL ("bad") cholesterol above 100 mg/dL were independent predictors of SVR.

Based on these findings, the researchers concluded, "Insulin resistance is not a relevant predictor of sustained virological response to pegylated interferon plus ribavirin in HIV-HCV coinfected patients."

Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Servicio de Análisis Clínicos & Unidad de Enfermedades Infecciosas, Hospital Universitario de Valme, Sevilla, Spain; Servicio de Medicina Interna-Enfermedades Infecciosas, Hospital Universitario de La Princesa, Madrid, Spain; Servicio de Medicina Interna, Hospital Juan Ramón Jiménez, Huelva, Spain; Unidad de Enfermedades Infecciosas, Hospital Universitario Virgen de la Victoria, Málaga, Spain.

7/7/09

References

N Merchante, I de Los Santos-Gil, D Merino, and others. Insulin resistance is not a relevant predictor of sustained virological response to pegylated interferon plus ribavirin in HIV/HCV co-infected patients. Journal of Hepatology 50(4): 684-692. April 2009.

C Cammà and S Petta. Insulin resistance in HCV mono-infected and in HIV/HCV co-infected patients: Looking to the future. Journal of Hepatology 50(4): 648-651. April 2009