title: Development and Validation of a Method to Estimate Insulin Sensitivity in Patients With and Without Type 1 Diabetes.
abstract: BACKGROUND
  People with type 1 diabetes (T1D) have markedly reduced insulin sensitivity (IS) compared to their nondiabetic counterparts, and reduced IS is linked to higher cardiovascular risk.
  
  
  OBJECTIVE
  This study aimed to develop and validate an improved method for estimating IS in people with T1D.
  
  
  METHODS
  Prospective cohort.
  
  
  METHODS
  Adults (36 with T1D, 41 nondiabetic) were recruited from the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study for measurement of IS by hyperinsulinemic-euglycemic clamp to develop a clinically useful IS prediction equation (eIS) for T1D and nondiabetic individuals. These equations were then compared with previously published equations from the SEARCH and Pittsburgh Epidemiology of Diabetes Complications studies for the ability to predict measured IS in test sets of adults and adolescents from independent clamp studies.
  
  
  METHODS
  None.
  
  
  METHODS
  Comparison of clamp-measured IS to estimated IS.
  
  
  RESULTS
  The best-fit prediction model (eIS) differed by diabetes status and included waist circumference, triglycerides, adiponectin, and diastolic blood pressure in all CACTI adults and insulin dose in adults with T1D (adjusted R(2) = 0.64) or fasting glucose and hemoglobin A1c (HbA1c) in nondiabetic adults (adjusted R(2) = 0.63). The eIS highly correlated with clamp-measured IS in all of the non-CACTI comparison populations (r = 0.83, P = .0002 in T1D adults; r = 0.71, P = .01 in nondiabetic adults; r = 0.44, P = .008 in T1D adolescents; r = 0.44, P = .006 in nondiabetic adolescents).
  
  
  CONCLUSIONS
  eIS performed better than previous equations for estimating IS in individuals with and without T1D. These equations could simplify point-of-care assessment of IS to identify patients who could benefit from targeted intervention.
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Lindsey M
authors.initials: LM
authors.lastname: Duca
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: David M
authors.initials: DM
authors.lastname: Maahs
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Irene E
authors.initials: IE
authors.lastname: Schauer
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Bergman
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Kristen J
authors.initials: KJ
authors.lastname: Nadeau
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Petter
authors.initials: P
authors.lastname: Bjornstad
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Marian
authors.initials: M
authors.lastname: Rewers
authors.affiliation: Barbara Davis Center for Diabetes (L.M.D., D.M.M., P.B., M.R., J.K.S.-B.), School of Medicine, University of Colorado, Aurora, Colorado 80045; Colorado School of Public Health (L.M.D., D.M.M., J.K.S.-B.), University of Colorado, Aurora, Colorado 80045; Division of Endocrinology, Metabolism, and Diabetes (I.E.S., B.C.B.), Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado 80045; Division of Pediatric Endocrinology (K.J.N.), Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045; and Denver VA Medical Center (I.E.S.), Denver, Colorado 80220.
authors.forename: Janet K
authors.initials: JK
authors.lastname: Snell-Bergeon
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012727:Sex Characteristics; D055105:Waist Circumference; D055815:Young Adult