title: Defining insulin resistance from hyperinsulinemic-euglycemic clamps.
abstract: OBJECTIVE
  This study was designed to determine a cutoff point for identifying insulin resistance from hyperinsulinemic-euglycemic clamp studies performed at 120 mU/m(2)·min in a white population and to generate equations from routinely measured clinic and blood variables for predicting clamp-derived glucose disposal rate (GDR), i.e., insulin sensitivity.
  
  
  METHODS
  We assembled data from hyperinsulinemic-euglycemic clamps (120 mU/m(2)·min insulin dose) performed at the Pennington Biomedical Research Center between 2001 and 2011. Subjects were divided into subjects with diabetes (n = 51) and subjects without diabetes (n = 116) by self-report and/or fasting glucose ≥126 mg/dL.
  
  
  RESULTS
  We found that 75% of individuals with a GDR <5.6 mg/kg fat-free mass (FFM) + 17.7·min were truly insulin resistant. Cutoff values for GDRs normalized for body weight, body surface area, or FFM were 4.9 mg/kg·min, 212.2 mg/m(2)·min, and 7.3 mg/kgFFM·min, respectively. Next, we used classification tree models to predict GDR from routinely measured clinical and biochemical variables. We found that individual insulin resistance could be estimated with good sensitivity (89%) and specificity (67%) from the homeostasis model assessment of insulin resistance (HOMA-IR) >5.9 or 2.8< HOMA-IR <5.9 with HDL <51 mg/dL.
  
  
  CONCLUSIONS
  We developed a cutoff for defining insulin resistance from hyperinsulinemic-euglycemic clamps. Moreover, we now provide classification trees for predicting insulin resistance from routinely measured clinical and biochemical markers. These findings extend the clamp from a research tool to providing a clinically meaningful message for participants in research studies, potentially providing greater opportunity for earlier recognition of insulin resistance.
authors.affiliation: Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA.
authors.forename: Charmaine S
authors.initials: CS
authors.lastname: Tam
authors.forename: Wenting
authors.initials: W
authors.lastname: Xie
authors.forename: William D
authors.initials: WD
authors.lastname: Johnson
authors.forename: William T
authors.initials: WT
authors.lastname: Cefalu
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Redman
authors.forename: Eric
authors.initials: E
authors.lastname: Ravussin
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003663:Decision Trees; D015309:Glucose Clamp Technique / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008875:Middle Aged; D008954:Models, Biological; D012016:Reference Values
chemical_list: D007328:Insulin