Risk factors for Type 2 Diabetes Mellitus in Chronic Hepatitis C Virus-Infected Patients: A Retrospective Cohort Study in Southern China

Background Chronic hepatitis C (CHC) is associated with an increased risk of type 2 diabetes mellitus (T2DM). However, regional variations in HCV genotypes and clinical characteristics may influence this association. This study aimed to investigate the association between chronic Hepatitis C virus (CHC) infection and the development of T2DM of CHC patients in southern China. Methods A retrospective cohort study analyzed 442 CHC patients (242 non-diabetic, 200 diabetic) from 2010–2018. Biochemical parameters, HCV genotypes, and clinical characteristics were compared. Multivariate logistic regression and ROC analysis were performed to evaluate predictors of T2DM. Results The CHC + DM group exhibited significantly higher age, BMI, fasting blood glucose, fasting insulin, HOMA-IR(Homeostasis Model Assessment-Insulin Resistance) index, transaminases alanine transaminase (ALT) and aspartate transaminase (AST), total bilirubin, γ-Glutamyl Transferase (GGT), and cirrhosis prevalence (all P < 0.05). Logistic regression analysis showed that age (OR: 1.09), fasting blood glucose (OR: 16.20), fasting insulin (OR: 1.23), HOMA-IR (OR: 0.48), and GGT (OR: 1.01), cirrhosis (OR: 15.32) and hypertension (OR: 31.00) were the risk factors of DM in CHC patients. HCV genotype 3a was more prevalent in T2DM patients ( P  = 0.008). Receiver Operating Characteristic curve analysis highlighted fasting glucose (AUC = 0.904) as the strongest predictor. Conclusion Age, metabolic dysregulation, liver cirrhosis, hypertension, and HCV genotype 3a are key risk factors for T2DM in CHC patients. Early screening for glucose intolerance and genotype-specific interventions are critical in high-risk populations.