title: Assessment of insulin sensitivity by the hyperinsulinemic euglycemic clamp: Comparison with the spectral analysis of photoplethysmography.
abstract: We compare spectral analysis of photoplethysmography (PTG) with insulin resistance measured by the hyperinsulinemic euglycemic clamp (HEC) technique.
  
  
  
  A total of 100 nondiabetic subjects, 43 men and 57 women aged 20-63years, 30 lean, 42 overweight and 28 obese were enrolled in the study. These patients underwent an examination with HEC, and an examination with the PTG spectral analysis and calculation of the PTG Total Power (PTG-TP). Receiver-operating characteristic (ROC) curves were constructed to determine the specificity and sensitivity of PTG-TP in the assessment of insulin resistance.
  
  
  
  There is a moderate correlation between insulin sensitivity (M-value) and PTG-TP (r=- 0.64, p<0.0001). The ROC curves showed that the most relevant cutoff to the whole study group was a PTG-TP>406.2. This cut-off had a sensitivity=95.7%, specificity =84,4% and the area under the ROC curve (AUC)=0.929 for identifying insulin resistance. All AUC ROC curve analysis were significant (p<0.0001).
  
  
  
  The use of the PTG-TP marker measured from the PTG spectral analysis is a useful tool in screening and follow up of IR, especially in large-scale studies.
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences - State University of Campinas (UNICAMP), Campinas, SP, Brazil. Electronic address: aglecios@fcm.unicamp.br.
authors.forename: Aglecio Luiz
authors.initials: AL
authors.lastname: De Souza
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences - State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Gisele Almeida
authors.initials: GA
authors.lastname: Batista
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences - State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Sarah Monte
authors.initials: SM
authors.lastname: Alegre
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis*; D003940:Diagnostic Techniques, Endocrine / Q000592:standards; D005260:Female; D015309:Glucose Clamp Technique / Q000379:methods*; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D017156:Photoplethysmography / Q000379:methods*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D001786:Blood Glucose
keywords: Diabetes; Hyperinsulinemic euglycemic clamp; Insulin resistance; Photoplethysmography; ROC curve