Insulin resistance derived from zinc deficiency in non-diabetic patients with chronic hepatitis C

Abstract

Chronic hepatitis C virus (HCV) infection frequently evokes metabolic abnormalities including insulin resistance. A decrease in serum zinc (Zn) levels is often observed in association with hepatic fibrosis. Zn also plays important roles in insulin secretion. However, little is known about the relationship between Zn deficiency and insulin resistance in patients with HCV-related chronic liver disease. The main purpose of this study was to examine the contribution of Zn deficiency to insulin resistance in patients with chronic hepatitis C (CH-C). Forty-eight non-diabetic patients with CH-C were enrolled. Serum alanine aminotransferase (ALT), ferritin and Zn levels were examined in the enrolled patients with CH-C. Insulin resistance was determined by the Homeostasis model for assessment of insulin resistance (HOMA-IR). Zn deficiency was defined as serum Zn levels <65 μg/dl. Seven out of the 48 (15%) patients with CH-C fulfilled the criteria for Zn deficiency. Serum Zn levels were inversely correlated with serum ferritin levels (r=-0.364, p=0.0140). The values of HOMA-IR were positively linked to serum ferritin levels (r=0.299, p=0.0484). The mean value of HOMA-IR in the Zn deficiency group was significantly higher than that in the normal-range Zn group (3.76±0.66 vs. 2.08±1.35, p=0.0019). Serum ALT levels were also closely associated with serum ferritin levels (r=0.727, p<0.001). These findings were independent of HCV genotypes or loads of HCV-RNA. Our data suggest that iron overload in patients with CH-C derives from Zn deficiency and thereby causes insulin resistance.