Table 3.

Glucose homeostasis and substrate oxidation

	IFG	IGT	IFG + IGT
FPG, mg/dl
Pre	105.2 ± 1.9†	94.6 ± 1.6	104.9 ± 1.6†
Δ	−9.6 ± 1.8*†	−0.8 ± 1.3	−8.7 ± 2.8*†
FPI, μU/ml
Pre	18.6 ± 3.9	13.2 ± 2.2	22.2 ± 4.0
Δ	−7.1 ± 2.4*	−2.9 ± 1.2*	−9.1 ± 3.2*
2-h OGTT glucose, mg/dl
Pre	116.1 ± 4.0	153.7 ± 3.7‡	163.9 ± 7.9‡
Δ	6.9 ± 11.2	−12.2 ± 6.5	−9.5 ± 12.6
2-h OGTT Insulin, μU/ml
Pre	98.5 ± 42.8	135.2 ± 37.6	145.1 ± 25.4
Δ	−39.8 ± 25.1	−63.1 ± 26.1*	−40.0 ± 24.7
GLC iAUC OGTT, mg·dl−1·180 #
Pre	2,508.5 ± 433.5	5,164.4 ± 465.7‡	4,503.5 ± 482.3‡
Δ	142.8 ± 772.5	−1,027.4 ± 269.7*	−667.8 ± 718.7
INS iAUC OGTT, μU·ml−1·180
Pre	4,974.6 ± 1,002.9	7,981.5 ± 2,060.6	8,114.8 ± 1,609.1
Δ	−1,930.7 ± 625.5*	−3,551.5 ± 1,525.4*	−2,954.2 ± 844.8*
RQfasted#
Pre	0.87 ± 0.02	0.86 ± 0.03	0.83 ± 0.02
Δ	−0.04 ± 0.02	−0.05 ± 0.02*	0.01 ± 0.02
CHO oxidationfasted, mg·kg−1·min−1
Pre	1.4 ± 0.2	1.2 ± 0.2	1.0 ± 0.2
Δ	−0.6 ± 0.3*	−0.4 ± 0.1*	0.3 ± 0.2
Lipid oxidationfasted, mg·kg−1·min−1
Pre	0.3 ± 0.1	0.4 ± 0.1	0.5 ± 0.1
Δ	0.1 ± 0.1	0.3 ± 0.1	0.1 ± 0.1
RQ clamp
Pre	0.86 ± 0.03	0.83 ± 0.03	0.81 ± 0.02
Δ	0.03 ± 0.02	0.02 ± 0.02	0.03 ± 0.03
CHO oxidationclamp, mg·kg−1·min−1
Pre	1.4 ± 0.3	1.2 ± 0.2	0.9 ± 0.3
Δ	0.4 ± 0.2	0.5 ± 0.3	0.3 ± 0.3
Lipid oxidationclamp, mg·kg−1·min−1
Pre	0.5 ± 0.2	0.6 ± 0.1	0.7 ± 0.2
Δ	−0.1 ± 0.1	0.0 ± 0.1	−0.2 ± 0.1
NOGDclamp, mg·kg−1·min−1#
Pre	1.3 ± 0.6	1.6 ± 0.5	2.5 ± 0.7
Δ	1.3 ± 0.3*	1.4 ± 0.9*	−0.0 ± 0.5‡§

Data are means ± SE. FPG, fasting plasma glucose; FPI, fasting plasma insulin; iAUC, incremental area under the curve; GLC, glucose; INS, insulin; RQ, respiratory quotient; NOGD, nonoxidative glucose disposal.

^#Data were log-transformed for statistical analysis but are presented herein as raw values. ANOVA was performed to detect between-group differences. Between-group effect (

^†P < 0.05 vs. IGT;

^‡P < 0.05 and

^§P < 0.10 vs. IFG). Within effect (paired t-test;

^*P < 0.05, ^P < 0.09).