Association of Hepatitis C Virus Infection and Diabetes Mellitus

Abstract

Both hepatitis C virus infection (HCV) and diabetes mellitus type 2 (DM2) are chronic conditions with significant morbidity and mortality. Over 4 million Americans are seropositive for hepatitis C virus (HCV) infection. DM2 is approaching epidemic proportions worldwide, and by the year 2025, over 300 million people will have been diagnosed with diabetes mellitus. Epidemiologically, there is a relationship between DM2 and chronic HCV infection. Several potential mechanisms explaining this relationship have been suggested, the most important of which seems to be insulin resistance. HCV infection may lead to post receptor insulin signaling defects contributing to insulin resistance and leading to the development of DM2. HCV is also associated with hepatic steatosis to a greater extent than other inflammatory liver diseases. A significant association between elevated serum ferritin level and newly diagnosed DM2 also exists. Interferon-␣ (IFN-␣) therapy is also thought to contribute to the development of diabetes. Diabetes type 1 (DM1) has not been shown to be strongly associated with HCV infection. DM2 has been reported to increase the risk of hepatocellular carcinoma and is also thought to contribute to the excess mortality seen in patients with hepatocellular carcinoma. Given the major clinical implications of HCV and DM2 comorbidity, the question arises whether all patients with HCV should be screened for diabetes mellitus. There is no data evaluating outcomes with this kind of screening, and it may be premature to screen all HCV patients for DM2. However, as more data accumulates, it may become apparent that this is a valid intervention. (The Endocrinologist 2006;16: 41-48) Learning Objectives• Point out ways in which demographic factors such as age and race may help to clarify the established association between type 2 diabetes mellitus (DM2) and hepatocellular carcinoma (HCC). • Identify which of the several pathophysiological mechanisms that have been proposed for the development of DM in HCV-infected individuals is most plausible. • Describe possible complications of these comorbid disorders, particularly HCC, and address the question of whether to screen all HCV-infected persons for DM2.O ver 4 million Americans are seropositive for hepatitis C virus (HCV), which translates to approximately 1.8% of the U.S. population. Currently, over 2.7 million Americans are chronically infected with HCV, and it is the leading cause of chronic liver disease. 1 The current treatment for chronic HCV infection achieves sustained viral clearance in only approximately 50% of patients with chronic HCV-related liver disease. Hepatitis C is associated with numerous adverse effects, including type 2 diabetes mellitus (DM2), and may progress to hepatocellular carcinoma. 2 DM2 is approaching epidemic proportions worldwide and by the year 2025, over 300 million people will have been diagnosed with diabetes mellitus. 3 Both HCV and DM2 are chronic conditions with significant morbidity and mortality. Hence, identification of risk of com...