CST3 and type 2 diabetes mellitus: Combination strategies provided flexible performance: "OR" rule (either high cystatin C or low IBIL) achieved 80.6% sensitivity, while "AND" rule (both high cystatin C and low IBIL) reached 94.9% specificity.<h4>Conclusions</h4>Serum cystatin C and IBIL are independent predictors of STDR in T2DM.