Elevated serum tumor necrosis factor alpha and ferritin may contribute to the insulin resistance found in HCV positive Egyptian patients.
OBJECTIVE: There is evidence of an increased incidence of insulin resistance and diabetes mellitus (DM) in patients with hepatitis C virus (HCV) infection. Several mechanisms have been proposed, including inadequate insulin secretion or interference with signaling within the insulin receptor. We assessed serum tumor necrosis factor alpha (TNFalpha) and ferritin levels as potential mediators of insulin resistance in HCV positive Egyptian patients. PATIENTS AND RESULTS: Patients (n = 27) with HCV infection, patients (n = 23) with hepatitis C and DM (HCV + DM), patients (n = 22) with DM, and sex- and age-matched controls (n = 18) were included in this study. The degree of insulin resistance (HOMA index) was significantly higher in the HCV, HCV + DM and DM groups compared to the controls. The mean +/- SD of the HOMA index was 4.53 +/- 2.84, 6.1 +/- 2.36, 3.69 +/- 2.2 and 1.32 +/- 0.49, in HCV, HCV + DM, DM and controls, respectively. Serum TNFalpha levels were significantly higher in the HCV, HCV + DM groups compared with the healthy controls and DM patients (p < 0.001). The median (range) values of TNFalpha in HCV, HCV + DM, DM patients and controls subjects were 25.5 (0.43-124.0), 19.8 (0.51-139), 0.85 (0-10.5) and 0.32 (0-5.8) pg/mL, respectively. There was a significant positive correlation between the HCV load and both HOMA index and TNF alpha level. HCV and HCV + DM patients also had significantly higher serum ferritin levels compared with healthy controls and patients with DM. The mean +/- SD of serum ferritin in HCV, HCV + DM, DM patients and controls subjects was 258.1 +/- 116.2, 285.8 +/- 124.3, 86.9 +/- 41.8 and 159.9 +/- 76.9 ng/mL, respectively. CONCLUSION: Patients with HCV infection had a significantly higher level of TNFalpha and ferritin which may explain their insulin resistance. HOMA index and serum TNFalpha levels correlated positively with the HCV load.