The measurement of in vivo insulin sensitivity was performed using the minimal model analysis of the frequently sampled intravenous glucose tolerance test (FSIVGTT).
In the minimal adequate analysis of covariance (ANCOVA) model (Table 2), the only statistically significant effects on log variance were due to log mean, to treatment, and to treatment × log mean interaction, indicating differences in slope among treatments.
To determine the effect of metformin on insulin and glucose dynamics in I-R ponies, six ponies were studied in a cross-over design by Minimal Model analysis of a frequently-sampled intravenous glucose tolerance test (FSIGT).
Indices of insulin sensitivity (SI) and glucose effectiveness (SG) were determined by minimal model analysis of insulin and glucose concentrations during the FSIVGTT as previously described [ 32].
The euglycemic-hyperinsulinemic clamp (6) and the minimal modeling analysis of the frequently sampled intravenous glucose tolerance test (FSIVGTT) (7) are currently considered the gold standard measures for the assessment of IS.
The minimal model analysis of glucose and insulin levels during intravenous or oral glucose loading allows assessment without the use of intravenous insulin, but still necessitates multiple blood samples.
An IVGTT-derived measure of insulin sensitivity, Si, (IVGTT-Si) was provided by minimal model analysis of IVGTT glucose and insulin concentrations, implemented according to an optimised algorithm, as described previously [ 16].
Rotter observed that fasting insulin reflects physiologic processes other than IR and so is a relatively crude measure, with heritability less than that for insulin sensitivity based on the minimal model analysis of the intravenous glucose tolerance test (14).
The insulinogenic index was calculated as where CP 0 and G 0 are the baseline fasting plasma levels of plasma C-peptide and glucose, respectively, and CP30 and G 30 are their levels at 30 min. β-Cell function was also estimated by minimal model analysis of plasma glucose and C-peptide response to a 2-h 75 g OGTT (17).
The finding that gene expression profiles in KIKO mice skeletal muscle and liver were suggestive of decreased insulin sensitivity prompted us to test insulin sensitivity in 14 non-diabetic FRDA patients by intravenous glucose-tolerance testing and minimal model analysis of glucose kinetics.
