In multivariate logistic regression models adjusting for age, HbA1c, WC, systolic BP, diastolic BP, drinking, smoking and exercise habits, family history of diabetes, hsCRP, GGT, AST, ALT, TG, HDL-C, LDL-C and HOMA-IR, the adjusted RRs and 95% CI for incident type 2 diabetes across baseline quartile groups of serum ferritin levels were 1.10 (0.63–1.93), 1.16 (0.67–1.99), and 2.17 (1.27–3.72), respectively (P for trend = 0.013). Here, GPT is linked to diabetes mellitus.