Insulin Resistance Independently Associated With Chronic Hepatitis C

NEW YORK (Reuters Health) Feb 27 - The results of a study published in the February issue of Gastroenterology suggest that insulin resistance is a specific feature of chronic hepatitis C virus (HCV) infection, independent of disease severity or the presence of metabolic factors.

Insulin resistance is also significantly more common in patients chronically infected with hepatitis C genotypes 1 and 4, and in patients with high viral loads, French investigators report. They also found insulin resistance to be an independent predictor of significant fibrosis.

"HCV infection is now recognized as a systemic disease involving lipid metabolism, oxidative stress, and mitochondrial function," lead author Dr. Rami Moucari, of Universite Denis Diderot-Paris, and colleagues write. "In some previous studies, HCV infection was associated with an increased risk of diabetes mellitus or insulin resistance."

In a prospective study, the researchers examined the association between insulin resistance, HCV genotypes, serum HCV RNA level, and liver fibrosis stage in 500 consecutive patients with chronic HCV who were evaluated on the day of liver biopsy.

Insulin resistance was present in 150 (32.4%) of the 462 non-diabetic patients. In this group, insulin resistance was associated with the metabolic syndrome, genotypes 1 and 4, significant fibrosis, severe steatosis, and being older than 40 years of age.

Among 145 chronic HCV patients without metabolic syndrome or significant fibrosis, insulin resistance was diagnosed in 22 (15%). Insulin resistance in this population was also associated with genotypes 1 and 4, high serum HCV RNA level, and moderate-to-severe liver necro-inflammation.

Insulin resistance was more frequent in chronic HCV patients (35%) than a group of matched chronic hepatitis B patients (5.0%). All insulin resistance parameters were also significantly higher among the chronic HCV patients (p < 0.001).

"Insulin resistance should be assessed in the routine management of patients with chronic hepatitis C," Dr. Moucari said in an interview with Reuters Health. "Surveillance of insulin resistance should be performed during the management course of patients with hepatitis C, and subsequent management of insulin resistance is needed in those patients who develop features of diabetes subsequently."

"A large study is ongoing to assess the impact of insulin resistance on the response to antiviral treatment in patients with chronic hepatitis C, and to assess the evolution of the 'virus induced' insulin resistance according to viral eradication," Dr. Moucari added.

Another study is assessing the "presence of a specific sequence within the virus genome that confers to HCV this feature of a 'metabolic virus.'"

Gastroenterology 2008;134:416-423.