Diabetes, Vol 27, Issue 7 715-725, Copyright © 1978 by American Diabetes Association
Reproducibility and comparative analysis of repeated intravenous and oral glucose tolerance tests
OP Ganda, JL Day, JS Soeldner, JJ Connon and RE Gleason
We have developed a methodology for measuring the reproducibility of the
oral glucose tolerance test (OGTT) and the intravenous glucose tolerance
test (IVGTT) in normal subjects and in offspring of conjugal diabetic
parents. Both groups of subjects revealed more striking correlations of
several parameters of blood glucose and insulin secretion between two
IVGTTs than between two OGTTs. Employing arbitrary criteria, we calculated
a "reproducibility index" as a quantitative measure of blood glucose
variability in each subject. No significant difference was found in the
reproducibility of OGTT versus IVGTT, nor in normals versus the offspring.
Only about 50 per cent of the tests in normals and in the offspring could
be considered to be "reproducible." The offspring revealed greater
correlations of several parameters, particularly insulin secretion, between
the two IVGTTs and between the two OGTTs as compared with the normal group.
However, the blood glucose variations tended to be considerably greater in
the offspring from one to the other test.