Location: Children's Nutrition Research CenterTitle: Triglyceride glucose index as a surrogate measure of insulin sensitivity in obese adolescents with normoglycemia, prediabetes, and type 2 diabetes mellitus: Comparison with the hyperinsulinemic–euglycemic clamp Author
|Mohd Nor, Noor - University Of Pittsburgh Medical Center|
|Lee, So - University Of Pittsburgh Medical Center|
|Bacha, Fida - Children'S Nutrition Research Center (CNRC)|
|Tfayli, Hala - American University Of Beirut|
|Arslanian, Silva - University Of Pittsburgh Medical Center|
Submitted to: Pediatric Diabetes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2015
Publication Date: 8/6/2015
Citation: Mohd Nor, N.S., Lee, S.J., Bacha, F., Tfayli, H., Arslanian, S. 2015. Triglyceride glucose index as a surrogate measure of insulin sensitivity in obese adolescents with normoglycemia, prediabetes, and type 2 diabetes mellitus: Comparison with the hyperinsulinemic–euglycemic clamp. Pediatric Diabetes. doi:10.1111/pedi.12303.
Interpretive Summary: There is a need to identify simple measures to estimate insulin sensitivity in large scale studies of overweight/obese children. We compared an index of insulin sensitivity, the triglyceride glucose index (TyG) to insulin sensitivity measured from the gold standard method of the hyperinsulinemic-euglycemic clamp, and to other indices of insulin sensitivity. We found that the TyG index was adequate to evaluate insulin sensitivity in large scale studies. Given that it is based on easily obtainable blood levels of glucose and lipids, this index represent an adequate measure of insulin sensitivity in large scale studies.
Technical Abstract: There is a need for simple surrogate estimates of insulin sensitivity in epidemiological studies of obese youth because the hyperinsulinemic-euglycemic clamp is not feasible on a large scale. Objectives: (i) To examine the triglyceride glucose (TyG) index (Ln[fasting triglycerides (mg/dL)'×'fasting glucose (mg/dL)/2]) and its relationship to in vivo insulin sensitivity in obese adolescents (OB) along the spectrum of glucose tolerance and (ii) to compare TyG index with triglyceride/high-density lipoprotein TG/HDL and 1/fasting insulin (1/IF), other surrogates of insulin sensitivity. Cross-sectional data in 225 OB with normal glucose tolerance (NGT), prediabetes (preDM), and type 2 diabetes (T2DM) who had a 3-h hyperinsulinemic-euglycemic clamp and fasting lipid measurement. Insulin-stimulated glucose disposal (Rd) declined significantly across the glycemic groups from OB-NGT to OB-preDM to OB-T2DM with a corresponding increase in TyG index (8.3'+/-'0.5, 8.6'+/-'0.5, 8.9'+/-'0.6, p'<'0.0001). The correlation of TyG index to Rd was -0.419 (p'<'0.0001). The optimal TyG index for diagnosis of insulin resistance was 8.52 [receiver operating characteristic-area under the ROC curves (ROC-AUC) 0.750, p'<'0.0001]. The ROC-AUC for 1/IF was 0.836. In multiple regression analysis, 64.8% of the variance in Rd was explained by TyG index, 1/IF, body mass index (BMI) z-score, glycemic group, and sex. The TyG index affords an easily and widely available simple laboratory method as a surrogate estimate of insulin sensitivity that could be used repeatedly in large-scale observational and/or interventional cohorts of OB. Although not superior to 1/IF, TyG index offers the advantage of having a standardized method of measuring triglyceride and glucose, which is not the case for insulin assays.