title: Validation of steady-state insulin sensitivity indices in chronic kidney disease.
abstract: OBJECTIVE
  Insulin resistance may contribute to cardiovascular disease and the progression of renal insufficiency in patients with chronic kidney disease (CKD). However, feasible methods for estimating insulin sensitivity in large-population CKD studies have not been validated. The purpose of this study was to attempt to validate several commonly used steady-state insulin sensitivity (SI-SS) indices in a CKD population.
  
  
  METHODS
  Twenty-seven subjects with estimated glomerular filtration rate (eGFR) ranging from 70 to <10 ml/min per 1.73 m2 (median eGFR = 48) underwent a frequently sampled intravenous glucose tolerance test (FSIVGTT) on a single occasion. Correlations were obtained between the minimal model-derived insulin sensitivity parameter from the FSIVGTT (SI-FSIVGTT) and seven SI-SS indices derived from fasting insulin and glucose data obtained just before the FSIVGTT.
  
  
  RESULTS
  Each of the seven steady-state indices was significantly correlated with SI-FSIVGTT. For indices obtained using the mean of four fasting insulin and glucose values over 15 min, Pearson correlation coefficients (|r|) ranged from 0.51 to 0.87 (P < 0.01 for each). For indices using single fasting insulin and glucose values, |r| ranged from 0.51 to 0.72 (P < 0.01 for each). By both the four and one time point approaches, 1/I(0) had the highest correlation with SI-FSIVGTT. The correlation with SI-FSIVGTT did not change significantly according to eGFR level for any of the SI-SS indices.
  
  
  CONCLUSIONS
  SI-SS indices are valid surrogates for SI-FSIVGTT in the CKD population. Their use will expand the range of testable hypotheses in CKD cohort studies.
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, University of Pennsylvania School of Medicine, Room 778, Clinical Research Building, 415 Curie Blvd., Philadelphia, PA 19104, USA. mcrutchl@mail.med.upenn.edu
authors.forename: Michael F
authors.initials: MF
authors.lastname: Crutchlow
authors.forename: Bruce
authors.initials: B
authors.lastname: Robinson
authors.forename: Binu
authors.initials: B
authors.lastname: Pappachen
authors.forename: Neil
authors.initials: N
authors.lastname: Wimmer
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Cucchiara
authors.forename: Debbie
authors.initials: D
authors.lastname: Cohen
authors.forename: Raymond
authors.initials: R
authors.lastname: Townsend
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D007674:Kidney Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged