Insulin Resistance and Diabetes in Patients with Chronic Hepatitis C

Symptoms: Some people with type 2 diabetes have no symptoms; others exerience symptoms that may include:

It is increasingly recognized that metabolic disorders, including insulin resistance and type 2 diabetes, appear to play a role in liver disease progression.

As reported in the May 2006 issue of Diabetes Care, Spanish researchers conducted a case-control study to assess pathogenic mechanisms that might contribute to diabetes in people with hepatitis C.

The study included 28 consecutive non-diabetic patients with chronic hepatitis C, and 14 control subjects with chronic hepatitis due to other causes. Both groups were closely matched in terms of clinical variables associated with insulin resistance and degree of liver fibrosis.

Results

There were no differences between the HCV positive and control groups regarding hepatic insulin extraction measured by calculating the ratio between C-peptide and insulin.

Insulin resistance, measured using the homeostasis model assessment of insulin resistance (HOMA-IR), was greater in HCV positive compared with HCV negative subjects (4.35 vs 2.58; P = 0.01).

Levels of all the proinflammatory cytokines analyzed -- tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptors 1 and 2 (sTNFR1 and sTNFR2), and interleukin-6 -- were significantly higher in the HCV positive patients.

sTNFR1 and sTNFR2 levels were directly correlated with HOMA-IR scores.

Baseline insulin secretion (HOMA-ß), as well as insulin and C-peptide responses after an intravenous glucagon challenge test, were significantly greater in HCV positive compared with HCV negative individuals.

Conclusion

The authors concluded that, "Insulin resistance mediated by proinflammatory cytokines, but not a deficit in insulin secretion, could be the primary pathogenic mechanism involved in the development of diabetes associated with HCV infection."

7/25/06

Reference
A Lecube, C Hernandez, J Genesca, and others. Glucose Abnormalities in Patients with Hepatitis C Virus Infection: Epidemiology and pathogenesis. Diabetes Care 29(5): 1096-1101. May 2006.