Association between serum total bilirubin levels and the risk of type 2 diabetes mellitus

Abstract Aim To confirm whether serum bilirubin is an independent risk factor of type 2 diabetes mellitus (T2DM) onset in patients with impaired fasting glycemia (IFG) and impaired glucose tolerance (IGT). Methods This was a prospective cohort study carried out at the Diabetic Identification Center of Tianjin Metabolic Diseases Hospital. Serum total bilirubin (TBIL) was measured at baseline and the patients were grouped according to baseline bilirubin quartiles. The outcome was the confirmation of T2DM by oral glucose tolerance test (OGTT) during the 3-year follow-up. Logistic regression was used to determine the risk factors for T2DM development and whether bilirubin levels are independently associated with T2DM development. Results Finally, 523 patients were analyzed. After 3 years, 310 participants were diagnosed with diabetes based on OGTT. Baseline quartiles of total bilirubin were inversely associated with diabetes risk, even after multivariable adjustment. The adjusted ORs for diabetes were 1.0 (reference), 0.83 (95% CI 0.74–0.96), 0.78 (95% CI 0.68–0.90), 0.74 (95% CI 0.64–0.87) for the 1st, 2nd, 3rd, and 4th quartiles of baseline serum total bilirubin, respectively ( P Conclusion In patients with IFG or IGT, low levels of serum total bilirubin were associated with a significantly increased risk of T2DM.