title: Measurement of insulin-mediated glucose uptake: direct comparison of the modified insulin suppression test and the euglycemic, hyperinsulinemic clamp.
abstract: BACKGROUND
  Two direct measurements of peripheral insulin sensitivity are the M value derived from the euglycemic, hyperinsulinemic clamp (EC) and the steady-state plasma glucose (SSPG) concentration derived from the insulin suppression test (IST). Prior work suggests that these measures are highly correlated, but the agreement between them is unknown. To determine the agreement between SSPG and M and to develop transformation equations to convert SSPG to M and vice versa, we directly compared these two measurements in the same individuals.
  
  
  METHODS
  A total of 15 nondiabetic subjects (9 women and 6 men) underwent both an EC and a modified version of the IST within a median interval of 5days. We performed standard correlation metrics of the two measures and developed transformation regression equations for the two measures.
  
  
  RESULTS
  The mean±SD age of the subjects was 57±7years and body mass index, 27.7±3.9kg/m(2). The median (interquartile range) SSPG concentration was 6.7 (5.1, 9.8) mmol/L and M value, 49.6 (28.9, 64.2) μmol/min/kg-LBM. There was a highly significant correlation between SSPG and M (r=-0.87, P <0.001). The relationship was best fit by regression models with exponential/logarithmic functions (R(2)=0.85). Bland-Altman plots demonstrated an excellent agreement between these measures of insulin action.
  
  
  CONCLUSIONS
  The SSPG and M are highly related measures of insulin sensitivity and the results provide the means to directly compare the two measurements.
authors.affiliation: Stanford University, Division of Cardiovascular Medicine, Falk CVRC, 300 Pasteur Dr., Stanford, CA 94305-5406, USA. knowlej@stanford.edu
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Knowles
authors.forename: Themistocles L
authors.initials: TL
authors.lastname: Assimes
authors.forename: Philip S
authors.initials: PS
authors.lastname: Tsao
authors.forename: Andrea
authors.initials: A
authors.lastname: Natali
authors.forename: Andrea
authors.initials: A
authors.lastname: Mari
authors.forename: Thomas
authors.initials: T
authors.lastname: Quertermous
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Reaven
authors.forename: Fahim
authors.initials: F
authors.lastname: Abbasi
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D005260:Female; D005765:Gastrointestinal Agents; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D006801:Humans; D007004:Hypoglycemic Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015282:Octreotide; D012044:Regression Analysis
chemical_list: D001786:Blood Glucose; D005765:Gastrointestinal Agents; D007004:Hypoglycemic Agents; D007328:Insulin; D005947:Glucose; D015282:Octreotide