Table 2.

Hormone and substrate concentrations at baseline and during the clamp

	Fasting Glucose, mg/dl	2-h Glucose, mg/dl	Insulin, μU/ml	C-Peptide, ng/ml	FFA, μmol/l	Glycerol, μmol/l	Lactate, mmol/l
Baseline
NGT	91±1.2	102±6.7‡	10.0±1.8	2.6±0.2	585±37	88±9	0.7±0.09
IFG	112±3.0*	93±6.2‡	11.4±1.3	3.2±0.2*	543±43	101±19	0.5±0.07
IGT/IFG	111±2.4*	163±4.0	10.0±1.6	2.8±0.2	668±58	105±13	0.9±0.15†
Low-dose (4 mU·m2·min−1) clamp
GIR, mg glucose·kg−1·min−1
NGT	0.31±0.12	93±1.0	11.1±1.8	2.2±0.2	498±40	71±6	0.4±0.04
IFG	0.00±0.00*	100±2.0*	12.6±0.7	2.6±0.2	491±50	82±10	0.5±0.07
IGT/IFG	0.00±0.00*	102±1.6*	12.5±1.5	2.3±0.2	496±45	85±9	0.6±0.08
High-dose (40 mU·m2·min−1) clamp
GIR, mg glucose·kg−1·min−1
NGT	3.8±0.5	89±1.0	76±8	1.3±0.2	59±18	39±6	0.7±0.05
IFG	4.0±0.6	90±1.3	70±10	1.3±0.2	97±41	45±8	0.6±0.07
IGT/IFG	3.1±0.5	89±2.7	69±5.4	1.1±0.1	65±19	56±14	0.8±0.10

Values are means ± SE. GIR, glucose infusion rate.

^*P < 0.05 vs. NGT;

^†P < 0.05 vs. IFG;

^‡P < 0.05 vs. IFG/IGT.