Patient: Male, 55 Final Diagnosis: Hepatitis C Symptoms: Icterus Medication: - Clinical Procedure: - Specialty: Endocrinology and Metabolic Objective: Unusual clinical course Background: Chronic hepatitis C virus (HCV) infection is associated with increased insulin resistance and risk of type 2 diabetes. Successful antiviral treatment can improve insulin resistance and allow a reduction in blood glucose-lowering treatment. There have been case reports of a reduced insulin requirement in this situation, although 1 case in which insulin was stopped exhibited a subsequent deterioration in glycemic control. Case Report: A 55-year-old Italian man was diagnosed with HCV infection in 2000 at the age of 39 years and with type 2 diabetes 6 years later. He was started on metformin but progressed to multiple daily insulin injections after 3 years. He was treated with pegylated interferon, ribavirin, and telaprevir over 12 months from early 2013, and achieved a sustained virologic response and normalization of hepatic function within 6 months of starting therapy. He was subsequently able to reduce his insulin doses from 0.56 to 0.44 U/kg/day over the next 2 years and, based on a random serum C-peptide of 1.73 nmol/L (fasting reference range 0.37-1.47 nmol/L) in the presence of serum glucose 7.9 mmol/L (143 mg/dL) and negative glutamic acid decarboxylase antibodies, he accelerated withdrawal and stopped insulin 6 months later. He is currently taking linagliptin 5 mg daily with good glycemic control. His body mass index and HbA(1c) have remained < 25 kg/m(2) and < 6.0% (< 42 mmol/mol), respectively, throughout. Conclusions: This case shows that complete withdrawal of long-term insulin therapy may be possible after HCV treatment has induced a sustained virologic response.