NEW YORK (Reuters Health) – Patients with type 2 diabetes who also have liver cirrhosis associated with hepatitis C virus (HCV) infection fare significantly better when they’re treated with metformin, results of a French study indicate.

“We found that metformin treatment was independently associated with a decrease in HCC (hepatocellular carcinoma) occurrence and with a decreased rate of liver-related death,” the researchers report in the August issue of the Journal of Clinical Endocrinology and Metabolism.

The authors point out that type 2 diabetes and hyperinsulinemia are common in patients with HCV cirrhosis, and that there’s evidence indicating that insulin resistance plays a role in the development of liver cancer. Therefore, treatment with metformin could be beneficial in this setting.

To investigate, Dr. Emmanuel Cosson, with Hopital Jean Verdier in Bondy and Paris-Nord University, and colleagues studied a prospective cohort of 100 consecutive patients with ongoing HCV cirrhosis and type 2 diabetes, 26 of whom were treated with metformin.

During follow-up for a median of 5.7 years, 39 patients developed HCC and 33 either died of liver-related causes or underwent a liver transplant, according to the report.

The team found that the 5-year rate of HCC was 9.5% among the group receiving metformin compared with 31.2% in those who did not. On multivariate analysis, metformin was independently associated with reduced risk of HCC (hazard ratio 0.19, p=0.023).

Similarly, the corresponding rate of death or transplantation was 5.9% vs 17.4% in the two groups, respectively. This translated to an adjusted hazard ratio for death/transplantation of 0.22 (p=0.049), Dr. Cosson and colleagues report.

They note that this was an observational study, so cause and effect cannot be determined. “However,” they conclude, “our findings add to the increasing body of evidence and may justify the initiation of clinical trials evaluating metformin in patients with hyperinsulinemia and HCV cirrhosis.”

Impact of Metformin on the Prognosis of Cirrhosis Induced by Viral Hepatitis C in Diabetic Patients
J Clin Endocrinol Metab 2011;96.