Interferon-alpha reduces insulin resistance and beta-cell secretion in responders among patients with chronic hepatitis B and C

This study aimed at elucidating the effects of interferon (IFN)-a on glucose metabolism in patients with chronic hepatitis B and C infections. Twenty-eight biopsy-proven patients with chronic hepatitis B (ten cases) and hepatitis C (18 cases) were given IFN-α for a total of 24 weeks. The patients received a 75 g oral glucose tolerance test (OGTT), glucagon stimulation test, tests for type 1 diabetes-related autoantibodies and an insulin suppression test before and after IFN-α therapy. Ten of the 28 patients responded to IFN-a therapy. Steady-state plasma glucose of the insulin suppression test decreased significantly in responders (13.32 ′ 1.48 (S.E.M.) vs 11.33 ′ 1.19 mmol/l, P=0.0501) but not in non-responders (12.29 ′ 1.24 vs 11.11 ′ 0.99 mmol/l, P=0.2110) immediately after completion of IFN-a treatment. In the oral glucose tolerance test, no significant difference was observed in plasma glucose in either responders (10.17 ′ 0.23 vs 10.03 ′ 0.22 mmol/l) or non-responders (10.11 ′ 0.22 vs 9.97 ′ 0.21 mmol/l) 3 months after completion of IFN-α treatment. However, significant differences were noted in C-peptide in both responders (2.90 ′ 0.13 vs 2.20 ′ 0.09) nmol/l, P=0.0040) and non-responders (2.45 ′ 0.11 vs 2.22 ′ 0.08 nmol/l, P=0.0287) before vs after treatment. The changes of C-peptide in an OGTT between responders and non-responders were also significantly different (P=0.0028), with responders reporting a greater reduction in C-peptide. No case developed autoantibodies during the treatment. In patients who were successfully treated with IFN-α, insulin sensitivity improved and their plasma glucose stayed at the same level without secreting as much insulin from islet β-cells.