Decreased glucose effectiveness associated with decreased acute
insulin release is an artifact of the minimal-model method.
Finegood, Diane T., and Dan Tzur.
Departments of Medicine and Physiology, and the Surgical Medical
Research Institute, University of Alberta, Edmonton, Alberta, Canada
T6G 2S2
APStracts 3:0102E, 1996.
We previously demonstrated that minimal-model derived estimates of
glucose effectiveness (SG(FSIGT)) were reduced in islet transplanted
or streptozotocin treated dogs, and in patients with insulin
dependent diabetes mellitus. To ascertain the validity of our
observations, we compared SG(FSIGT) to estimates based on a basal
hormone replacement glucose clamp (SG(BRCLAMP)) and a basal hormone
replacement glucose tolerance test (SG(BRGTT)) in normal control
(CNTL, n = 12) and streptozotocin treated dogs with normal fasting
plasma glucose (STZ-Rx, n = 9). SG(FSIGT) was reduced in STZ-Rx as
compared to CNTL (P < 0.05). However, neither SG(BRCLAMP) or
SG(BRGTT) were reduced in the STZ-Rx group (P > 0.05).
Comparison of protocols for each subject indicated that SG(FSIGT) was
greater than either SG(BRCLAMP) or SG(BRGTT) in control subjects (P
< 0.002), but not in STZ-Rx dogs (P > 0.1). The
relationship of SG(FSIGT) to insulin secretory function suggests that
our previous conclusion that SG(FSIGT) was reduced in subjects with
limited insulin release may be an artifact of the minimal-model
method. Our results suggest that caution must be exercised in the
interpretation of differences in minimal-model estimates of glucose
effectiveness between subject groups with significantly different
levels of insulin secretory function.
Received 7 November 1995; accepted in final form 6 May 1996.
APS Manuscript Number E524-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96