TyG index cutoff point is an accurate marker for predicting the prevalence of metabolic syndrome in obese Caucasian subjects.

BACKGROUND: Recently, the triglyceride-glucose (TyG) index has been suggested as a surrogate insulin resistance marker. This index could act as an early screening marker in individuals with high risk of Metabolic Syndrome (MS) such as obesity subjects.

AIMS: The objective of this work was to detect the cut-off point of the TyG index for the diagnosis of MS according to ATPIII criteria on obese subjects and to compare with HOMA-IR.

METHODS: We conducted a cross sectional study in 1494 obese subjects. Measurements of adiposity parameters, blood pressure, fasting blood glucose, insulin concentration, insulin resistance (HOMA-IR), lipid profile, C reactive protein, adipokines and prevalence of Metabolic Syndrome were determined. The TyG index was calculated from the next equation: Ln (fasting triglycerides (mg/dl) x fasting glucose (mg/dl))/2.

RESULTS: A total of 1494 subjects were recruited, 421 males (28.1%) and 1073 females (71.8%) with an average age of 45.8+15.3 years (range: 29-62). A total of 677 subjects had MS (45.5%) and 817 did not show MS (54.6%). The averages of HOMA-IR and TyG index values increased as the components of MS were aggregated and both indexes were higher in subjects with MS. The area under the curve (AUC) of TyG index according ATPIII criteria showed values of 0.746 (0.721-0.771:p=0.001). The cut-off point according to the Youden index was 4.72, with sentivity and specificity of 87% and 88.2%, respectively. For the HOMA-IR, the area under the curve (AUC) showed values of 0.682 (0.654-0.710:p=0.01). The cutoff point was 3.23, with sentivity and specificity of 78% and 70.1%, respectively.

CONCLUSIONS: TyG index is more powerful for predicting MS than HOMA-IR in Caucasian obese subjects.