Characteristics of OGTT and Correlation Between the Insulin to C-Peptide Molar Ratio, HOMA-IR, and Insulin Antibodies in T2DM Patients

Figures & data

Table 1 Serum Glucose, Insulin, C-Peptide and ICPR Values in OGTTs Between the Two Groups (Median (Interquartile Range))

	0h	0.5h	1h	2h
Glucose (mmol/L)
IA+	7.25(2.11)	13.64(3.41)	17.56(4.94)	18.28(4.10)
IA-	7.84(2.49)	13.81(3.54)	17.33(5.32)	18.68(5.83)
Insulin (pmol/L)
IA+	56.19(93.64)*	145.00(215.59)	199.00(336.17)	289.70(455.30)*
IA-	29.56(41.49)	81.57(86.56)	134.35(126.71)	157.10(212.88)
C-peptide (nmol/L)
IA+	0.56(0.46)	0.78(0.88)	1.17(1.20)	2.02(1.52)
IA-	0.55(0.43)	0.79(0.65)	1.14(0.87)	1.62(1.20)
ICPR
IA+	0.09(0.29)*	0.14(0.25)*	0.15(0.25)*	0.15(0.22)*
IA-	0.07(0.05)	0.11(0.08)	0.11(0.05)	0.10(0.06)

Note: *Compared with the IA- group, P<0.05.

Abbreviation: ICPR, the insulin to C-peptide molar ratio.

Figure 1 Changing trends of serum glucose, insulin, C-peptide levels, and ICPR values in OGTTs between the IA+ group and IA- group in T2DM patients.

Notes: (A) serum glucose levels; (B) serum insulin levels. (C) serum C-peptide levels. (D) ICPR, the insulin to C-peptide molar ratio. Data are presented as median (interquartile range).

Table 2 Correlation Analysis of ICPR, HOMA-IR, and IAs

Index	Correlation Coefficient	P-value	95% CI
ICPR-0h	0.319	0.005	0.096~0.512
ICPR-2h	0.381	<0.001	0.165~0.562
HOMA-IR	0.221	0.054	−0.10~0.429

Abbreviations: HOMA-IR, homeostasis model assessment of insulin resistance; ICPR-0h, the insulin to C-peptide molar ratio at 0h in oral glucose tolerance test; ICPR-2h, the insulin to C-peptide molar ratio at 2h in oral glucose tolerance test.

Table 3 ROC Analysis of ICPR-0h, ICPR-2h for Predicting the Presence of IAs

Index	AUC	Se	Sp	Youden Index	P-value	95% CI
ICPR-0h	0.697	0.600	0.769	0.369	0.005	0.563~0.831
ICPR-2h	0.735	0.760	0.635	0.395	<0.001	0.616~0.853

Abbreviations: AUC, area under curve; Se, sensitivity; Sp, specificity.

Figure 2 ROC curves of ICPR-0h and ICPR-2h for the predictive value of IA.