ESPE Abstracts

Background: Triglyceride glucose (TyG) index, a product of fasting triglyceride and glucose, was widely used as an alternative tool for identifying insulin resistance in adults but not in children. Recent study in children showed association between the TyG index and HOMA-IR and a usefulness of TyG index as a surrogate marker of insulin resistance among adolescents.

Objective: To evaluated the potential role of the TyG index as a predictor of impaired glucose tolerance among overweight and obese children and adolescents and identified the cutoff values of TyG index for diagnosis of abnormal glucose tolerance test.

Method: Data of overweight and obese patients age 6–20 years who underwent clinical examination, fasting blood testing and oral glucose tolerance test at Phramongkutklao Hospital from January 2002 to December 2016 was reviewed. The TyG index was calculated as ln[fasting triglycerides (mg/dl) × fasting plasma glucose (mg/dl)/2]. Impaired glucose tolerance was defined as two-hour glucose levels of 140 to 199 mg/dl on the 75-gm oral glucose tolerance test.

Results: A total of 203 children and adolescents (122 males and 81 females) were included to our study. Mean age was 12.04+2.61 years (range 6.06–18.65) and BMI Z-score was 2.24+0.34 (range 1.41–3.01). One hundred and fifty-one children (74.4%) were obese. Of them, two (1%) had type 2 diabetes and 38(18.7%) had pre-diabetes: 1(0.5%) with impaired fasting glucose (IFG), 34 (16.7%) with impaired glucose tolerance (IGT) and 3(1.5%) with IFG and IGT. The patient was divided to two groups: normal glucose tolerance or NGT (N=163) and IGT (N=37) group. Age, fasting blood glucose, HbA1C and TyG index were significantly higher in IGT than the NGT group. The TyG index was 8.27+0.43 and 8.54+0.58 in NGT and IGT, respectively (P 0.001). The area under the receiver operating characteristics (ROC) curve for TyG index and IGT was 0.648. In subgroup analysis of patients age >13 years, the optimal cut-offs of the TyG index for diagnosis of impaired glucose tolerance was 8.3. The area under the ROC curve was 0.728 (95% confidence interval: 0.593–0.864) and represent sensitivity of 77.3% and specificity of 50%.

Conclusion: The TyG index is a simple parameter to use as a surrogate marker of impaired glucose tolerance in overweight and obese children age >13 years compared with oral glucose tolerance test.