Insulin resistance means a poorer response to anti-HCV therapy in HIV/HCV coinfected patients

HIV-positive patients coinfected with hepatitis C virus who have insulin resistance have a poor response to anti-hepatitis C therapy, according to a small Italian study published in the February 1^st edition of the Journal of Acquired Immune Deficiency Syndromes. The investigators suggest that diagnosing and correcting insulin resistance in coinfected patients before initiating therapy for hepatitis C could lead to better treatment outcomes.

Treatment with anti-HIV therapy has been associated with an increased risk of insulin resistance , glucose intolerance and type-2 diabetes. It has been suggested that protease inhibitors may have a significant role in the development of these side-effects, although traditional risk factors may also be important.

There is a relationship between infection with hepatitis C virus and an increased risk of insulin resistance. The presence of insulin resistance has been associated with poorer six month response to anti-hepatitis C treatment with pegylated interferon and ribavirin in patients monoinfected with hepatitis C.

Coinfection with hepatitis C is common in HIV-positive patients, and although insulin resistance occurs with greater frequency in coinfected than hepatitis C-monoinfected patients, its effect on the outcome of anti-hepatitis C therapy in coinfected patients is poorly understood.

Investigators therefore undertook a study to see if there was a relationship between insulin resistance and early response to anti-hepatitis C treatment in HIV/hepatitis C coinfection. An early response to hepatitis C therapy – an undetectable hepatitis C viral load after three months of treatment – is a good indication of the likely long-term success of such treatment.

The study involved 29 patients who received anti-hepatitis C therapy from January 2006. All were men and the median age was 43 years. Insulin resistance was present in ten patients (35%).

After three months of anti-hepatitis C therapy median ALT and AST levels fell significantly in both patients with insulin resistance (p

But despite these improvements in liver function, the investigators noted that there insulin resistance appeared to have a significant effect on the chances of achieving both an early and rapid virological response to treatment (undetectable hepatitis C viral load after a month of therapy).

A rapid response to therapy was achieved by eight of the patients without insulin resistance but one of the patients with insulin resistance.

Furthermore, of the 19 patients without insulin resistance, 16 had an undetectable hepatitis C viral load after three months of therapy with pegylated interferon and ribavirin. However, none of the ten patients with insulin resistance had an early virological response.

“In the present study, including only HIV/hepatitis C virus-infected subjects, we found that subjects without insulin resistance at baseline are more likely to reach rapid virological response and an early virological response than others…the presence of insulin resistance does not allow for the achievement of a rapid virological response and an early virological response”, write the investigators.

The investigators recommend that coinfected patients should always be monitored for the presence of insulin resistance before anti-hepatitis C therapy is initiated. They add, “the correction of insulin resistance, and the consequent recovery of insulin sensitivity, could improve early virological response in the HIV/hepatitis C-coinfected population treated with pegylated interferon and ribavirin.”