Figure 3

Distribution of ΔCA activities and δ_DOB ¹⁸O values against HbA1c (%) for non-diabetic control (NDC), pre-diabetes (PD) and type 2 diabetes (T2D).

(a), Plot represents the clear transitions of ΔCA activities and δ_DOB ¹⁸O from NDC (green) to PD (yellow) and T2D (red). (b), (c), From receiver operating characteristic (ROC) curves analysis, the optimal diagnostic cut-off points were determined. The ΔCA activity <−1.31 for NDC; ΔCA activity >3.15 for T2D and −1.31 ≤ ΔCA activity ≤ 3.15 for PD, whereas δ_DOB ¹⁸O ‰ <−1.14 for NDC; δ_DOB ¹⁸O ‰ >2.77 for T2D and −1.14 ≤ δ_DOB ¹⁸O ‰ ≤ 2.77 for PD. Data are means ± SD.