title: A Diagnostic Score for Insulin Resistance in Nondiabetic Patients with Ischemic Stroke or Transient Ischemic Attack.
abstract: OBJECTIVE
  We sought to develop an instrument to screen for insulin resistance in nondiabetic patients with recent ischemic stroke or transient ischemic attack (TIA).
  
  
  METHODS
  Subjects were 7262 nondiabetic patients aged greater than or equal to 40 years with ischemic strokes or TIA within the past 6 months. Features were analyzed in bivariate analysis for association with insulin resistance, measured by the homeostasis model assessment of insulin resistance (HOMA-IR). Features significantly associated with HOMA-IR (P < .05) were entered into multivariable analysis. The magnitudes of regression coefficients from the multivariable model were used to assign point values for 2 diagnostic scoring instruments: a basic instrument that did not incorporate laboratory test values and an enhanced instrument that did. The performance of the instruments was tested using receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  In the basic model, 5 features were retained in the multivariable regression analysis: male gender, abdominal obesity, body mass index (BMI), elevated waist-to-hip ratio, and systolic blood pressure. In the enhanced model, 4 features were retained in the multivariable regression analysis: BMI, abdominal obesity, fasting glucose greater than or equal to 100 mg/dL, and triglyceride/high-density lipoprotein ratio. In the basic model, the area under the ROC curve (aROC) was .73 in the validation cohort. In the enhanced model, the aROC was .78 in the validation cohort.
  
  
  CONCLUSIONS
  Our 2 scoring systems performed well in identifying stroke patients with insulin resistance, but they are probably not sufficiently accurate for high-stake clinical decisions. We suggest strategies for improving the accuracy of future instruments.
authors.affiliation: Department of Internal Medicine, Yale Health, Yale University, New Haven, Connecticut. Electronic address: jin.xu@yale.edu.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Viscoli
authors.affiliation: The University of Oxford and Oxford University Hospitals NHS Foundation Trust, Oxfordshire, UK.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Ford
authors.affiliation: Department of Neurological Sciences, Vermont College of Medicine, Burlington, Vermont.
authors.forename: Mark
authors.initials: M
authors.lastname: Gorman
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Walter N
authors.initials: WN
authors.lastname: Kernan
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D015992:Body Mass Index; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis; D005260:Female; D044882:Glucose Metabolism Disorders / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D002546:Ischemic Attack, Transient / Q000150:complications* / Q000175:diagnosis; D008075:Lipoproteins, HDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D056128:Obesity, Abdominal / Q000150:complications / Q000175:diagnosis; D011237:Predictive Value of Tests; D012372:ROC Curve; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000150:complications* / Q000175:diagnosis; D014280:Triglycerides / Q000097:blood; D049629:Waist-Hip Ratio
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D008075:Lipoproteins, HDL; D014280:Triglycerides
keywords: Stroke; insulin resistance; ischemic stroke; obesity; transient ischemic attack