Table 3.

Within-Subject Variability for 2-h Oral Glucose Tolerance Test Glucose and Breath-Derived Tests

	Lean		Obese		T2DM		All subjects
Test	CV	RMS-CV	CV	RMS-CV	CV	RMS-CV	CV	RMS-CV
2-h OGTT (mg/dL)	16.6 ± 8.2%	18.3	10.3 ± 6%	11.7	10.9 ± 5.2%	11.9	13 ± 7.1%bd	14.8
δ180 (‰)	5.3 ± 2.0%	5.6	7.6 ± 5.2%	8.9	10 ± 3.2%	10.4	7.4 ± 3.9%acd	8.3
AUC180 (‰ × min)	6.5 ± 3.6%	7.3	9.2 ± 8.9%	12.3	13.5 ± 4.3%	14.1	9.4 ± 6.3%b	11.2
Lox/Gox	6.5 ± 3.5%	7.3	8.7 ± 8.3%	11.6	13.3 ± 4.5%	14	9.2 ± 6%ab	11

Data are mean ± SD values.

Comparisons of coefficient of variationvalues across tests are presented in the second to last column for all subjects; superscripts indicate P < 0.05 comparing against ^a2-h oral glucose tolerance test (OGTT) blood glucose, ^bchange at 180 min (δ180), ^carea under the curve for enrichment to 180 min (AUC180), or ^dratio of lipid oxidation to glucose oxidation (Lox/Gox).

CV, coefficient of variation; RMS-CV, root mean squared CV; T2DM, type 2 diabetes mellitus.