Table 2.

OGTT Indexes of Insulin Sensitivity and β-Cell Function

	Y-NGT	O-NGT	O-IGT	P a
Glucose excursions during OGTT
ΔG0–30, mmol/L	39.3 ± 3.0	41.2 ± 3.1	39.6 ± 4.0	0.74
ΔG30–120, mmol/L	129.5 ± 17.2	156.8 ± 19.0	387.0 ± 21.4b,c	0.0001
Insulin sensitivity
HOMA-IR	1.21 ± 0.18	1.26 ± 0.13	1.56 ± 0.27	0.17
Matsuda index	11.0 ± 1.4	8.1 ± 0.7	6.5 ± 0.7b	0.009
Insulin concentrations and secretion during OGTT
ΔI0–30, nmol/L	4.6 ± 0.6	3.6 ± 0.5	2.5 ± 0.5b	0.03
ΔI30–120, nmol/L	24.9 ± 2.6	27.7 ± 3.6	31.0 ± 4.5b	0.48
ΔISR0–30, (nmol/min	22.6 ± 2.2	22.6 ± 2.4	13.7 ± 2.2b,c	0.02
ΔISR30–120, nmol/min	83.8 ± 5.2	101.6 ± 7.8	111.8 ± 8.4b	0.02
(ΔI/ΔG)0–30, pmol/mmol	127 ± 20	102 ± 17	68 ± 16b	0.02
(ΔI/ΔG)30–120, pmol/mmol	578 ± 479	415 ± 119	84 ± 12b,c	0.002
(ΔISR/ΔG)0–30, nmol/min/mmol/L	0.710 ± 0.099	0.683 ± 0.140	0.380 ± 0.073b,c	0.004
(ΔISR/ΔG)30–120, nmol/min/mmol/L	4.327 ± 4.429	1.480 ± 0.403	0.300 ± 0.025b,c	<0.0001
β-Cell function
Kd, pmol/m2/mM	4097 ± 1011	3560 ± 1379	1919 ± 508	0.03
Glucose sensitivity, pmol/min/m2/mM	509 ± 55	479 ± 65	266 ± 28b,c	0.04
(ΔI/ΔG)0–30 × Matsuda	1134 ± 176	752 ± 141	358 ± 74b,c	<0.0005
(ΔI/ΔG)0–120 × Matsuda	4026 ± 1864	1685 ± 351	462 ± 63b,c	<0.001
(ΔISR/ΔG)0–30 × Matsuda	7.9 ± 1.7	5.1 ± 1.1	2.3 ± 0.4b,c	<0.0002
(ΔISR/ΔG)0–120 × Matsuda	17.9 ± 5.9	7.4 ± 1.7	1.9 ± 0.3b,c	<0.0001

Abbreviations: HOMA-IR, homeostatic model assessment of insulin resistance; Kd, rate sensitivity.

^aOld vs young.

^b P < 0.05 vs Y-NGT.

^c P < 0.05 vs O-NGT.