INS and type 2 diabetes mellitus: Therefore, the objective of this study was to compare available, simple OGTT-based BCF indices that use plasma concentrations of glucose, insulin and/or C-peptide to identify their ability to discriminate glucose metabolism status (normal glucose metabolism [NGM], prediabetes [meaning impaired fasting glucose and/or impaired glucose tolerance] and type 2 diabetes), which may approximate conceptually a more physiological aspect of BCF assessment.