Usefulness of TyG-index to determines insulin resistance in obese adolescents

Abstract

Background: Obesity is associated with Insulin Resistance (IR). The Triglycerides Glucose (TyG) index have been used to assess IR, however it needs to establish cut-off points to use in the obese adolescence. Purpose: This study aims to analyse the TyG-index as marker of IR in obese adolescence. Methods: A cross sectional study was conducted on obese adolescents aged 13-18 years in secondary school. Anthropometric measurements were performed. Lipid profile, fasting blood glucose, and insulin level were measured. HOMA IR were calculated using the formula: [glucose (mg/dL) x Insulin (µu/L)] / 405, cut-off value to describes IR was > 3.43 for both sexes which performs for pediatric population. TyG-index was calculated by the formula: TyG = Ln [TG (mg/dl) × FBG (mg/dl)]/2. Receiving operation characteristic (ROC) were carried out to determines area under curve (AUC) and cut-off points of IR for TyG-index determines by the biggest value of Youden index. Results: A total of 256 adolescents with obesity were participated this study. 59.8% (153/256 or) were non-IR, while 40.2% (103/256) had IR; Male: female ratio was 144/112. TyG-index was higher significantly in subjects with IR than non-IR (4.63 + 0.25 vs 4.46 + 0.26; p<0.05). HOMA-IR correlated positively with TyG-index (r=0.397, p=0.000). AUC for TyG-index was 0.703, p=0.000 (95% CI [0.639-0.770]). The best cut-off points for TyG-index to determines IR >4.50, with sensitivity of 70.3% and specificity of 63.23%. Conclusion: TyG-index is useful to be an alternative marker for assessing IR in obese adolescence with the best cut-off point to distinguish IR is > 4.50.