Fig. 1Relationship between fasting plasma glucose and early phase insulin secretion. Data represents the means and 95% confidence intervals. IGI, insulinogenic index; HOMA-IR, homeostasis model assessment-insulin resistance; ACR, acute C-peptide response. aRefers to P < 0.05 vs. F1 (FPG ≤ 86 mg/dL), bP < 0.01 vs. F1, cP < 0.05 vs. F2 (FPG 87-95 mg/dL), dP < 0.01 vs. F2.
Fig. 2Relationship between postprandial plasma glucose and early phase insulin secretion. Data represents means and 95% confidence intervals. IGI, insulinogenic index; HOMA-IR, homeostasis model assessment-insulin resistance; ACR, acute C-peptide response. aRefers to P < 0.05 vs. P1 (PP2 < 112 mg/dL), bP < 0.01 vs. P1, cP < 0.05 vs. P2 (PP2 113-132 mg/dL), dP < 0.01 vs. P2.
Fig. 3Relationship between postprandial plasma glucose and early phase insulin secretion. Data represents means and 95% confidence intervals. IGI, insulinogenic index; HOMA-IR, homeostasis model assessment-insulin resistance; ACR, acute C-peptide response. aRefers to P < 0.05 vs. H1 (HbA1c < 5.0%), bP < 0.01 vs. H1, cP < 0.05 vs. H2 (HbA1c 5.1-5.2%), dP < 0.01 vs. H2.
Table 1Clinical characteristics of study subjects
Table 2Comparison of insulin secretion and insulin resistance parameters according to glucose tolerance
Table 3Relationships among early phase insulin secretion indices adjusted by insulin resistance (IGI/HOMA-IR and ACR/HOMA-IR) and the fasting plasma glucose, the 2-hr plasma glucose, and the HbA1c