title: A comparison between the minimal model and the glucose clamp in the assessment of insulin sensitivity across the spectrum of glucose tolerance. Insulin Resistance Atherosclerosis Study.
abstract: An insulin-modified frequently sampled intravenous glucose tolerance test (FSIGTT) with minimal model analysis was compared with the glucose clamp in 11 subjects with normal glucose tolerance (NGT), 20 with impaired glucose tolerance (IGT), and 24 with non-insulin-dependent diabetes mellitus (NIDDM). The insulin sensitivity index (SI) was calculated from FSIGTT using 22- and 12-sample protocols (SI(22) and SI(12), respectively). Insulin sensitivity from the clamp was expressed as SI(clamp) and SIP(clamp). Minimal model parameters were similar when calculated with SI(22) and SI(12). SI could not be distinguished from 0 in approximately 50% of diabetic patients with either protocol. SI(22) correlated significantly with SI(clamp) in the whole group (r = 0.62), and in the NGT (r = 0.53), IGT (r = 0.48), and NIDDM (r = 0.41) groups (P < 0.05 for each). SI(12) correlated significantly with SI(clamp) in the whole group (r = 0.55, P < 0.001) and in the NGT (r = 0.53, P = 0.046) and IGT (r = 0.58, P = 0.008) but not NIDDM (r = 0.30, P = 0.085) groups. When SI(22), SI(clamp), and SIP(clamp) were expressed in the same units, SI(22) was 66 +/- 5% (mean +/- SE) and 50 +/- 8% lower than SI(clamp) and SIP(clamp), respectively. Thus, minimal model analysis of the insulin-modified FSIGTT provides estimates of insulin sensitivity that correlate significantly with those from the glucose clamp. The correlation was weaker, however, in NIDDM. The insulin-modified FSIGTT can be used as a simple test for assessment of insulin sensitivity in population studies involving nondiabetic subjects. Additional studies are needed before using this test routinely in patients with NIDDM.
authors.affiliation: Department of Medicine, University of Southern California Medical School, Los Angeles 90033.
authors.forename: M F
authors.initials: MF
authors.lastname: Saad
authors.forename: R L
authors.initials: RL
authors.lastname: Anderson
authors.forename: A
authors.initials: A
authors.lastname: Laws
authors.forename: R M
authors.initials: RM
authors.lastname: Watanabe
authors.forename: W W
authors.initials: WW
authors.lastname: Kades
authors.forename: Y D
authors.initials: YD
authors.lastname: Chen
authors.forename: R E
authors.initials: RE
authors.lastname: Sands
authors.forename: D
authors.initials: D
authors.lastname: Pei
authors.forename: P J
authors.initials: PJ
authors.lastname: Savage
authors.forename: R N
authors.initials: RN
authors.lastname: Bergman
mesh_terms: D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D015309:Glucose Clamp Technique; D018149:Glucose Intolerance / Q000097:blood*; D005951:Glucose Tolerance Test; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012016:Reference Values; D012044:Regression Analysis; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D007328:Insulin