Dt. Finegood et D. Tzur, REDUCED GLUCOSE EFFECTIVENESS ASSOCIATED WITH REDUCED INSULIN RELEASE- AN ARTIFACT OF THE MINIMAL-MODEL METHOD, American journal of physiology: endocrinology and metabolism, 34(3), 1996, pp. 485-495
Reduced glucose effectiveness associated with reduced insulin release:
artifact of the minimal-model method. Am. J. Physiol. 271 (Endocrinol
. Metab. 34): E485-E495, 1996.-We previously demonstrated that minimal
model-derived estimates of glucose effectiveness (S-G), based on the
frequently sampled intravenous glucose tolerance test (S-GFSIGT), were
reduced in islet-transplanted or streptozotocin-treated dogs and in p
atients with insulin-dependent diabetes mellitus. To ascertain the val
idity of our observations, we compared S-GFSIGT With estimates based o
n a basal hormone replacement glucose clamp (S-GBRCLAMP) and a basal h
ormone replacement glucose tolerance test (S-GBRGTT) in normal control
(CNTL, n = 12) and streptozotocin-treated dogs with normal fasting pl
asma glucose (STZ-Rx, n = 9). S-GFSIGT was reduced in STZ-Rx compared
with CNTL (P < 0.05). However, neither S-GBRCLAMP nor S-GBRGTT was red
uced in the STZ-Rx group (P > 0.05). Comparison of protocols for each
subject indicated that S-GFSIGT was greater than either S-GBRCLAMP or
S-GBRGTT in control (P < 0.002) but not in STZ-Rx dogs (P > 0.1). The
relationship of S-GFSIGT to insulin secretory function suggests that o
ur previous conclusion that S-GFSIGT was reduced in subjects with limi
ted insulin release may be an artifact of the minimal-model method. Ou
r results suggest that caution must be exercised in the interpretation
of differences in minimal-model estimates of S-G between subject grou
ps with significantly different levels of insulin secretory function.