The Cut-Off for Triglyceride-Glucose-Body Mass Index (TyG-BMI) and Triglyceride-Glucose-Waist Circumference Index (TyG-WC) Discriminating the Insulin Resistance Based on the SHBG Level and HOMA-IR Value in Caucasian Women with Polycystic Ovary Syndrome

TL;DR

This study identifies cut-off values for two indices to detect insulin resistance in Caucasian women with PCOS, using HOMA-IR and SHBG levels.

Contribution

The study provides novel cut-off values for TyG-BMI and TyG-WC indices specific to Caucasian women with PCOS.

Findings

Cut-off values for TyG-BMI and TyG-WC indices were determined for HOMA-IR ≥ 2.1 and SHBG < 41.5 nmol/L.

The indices showed high specificity and moderate sensitivity in identifying insulin resistance in the study population.

Abstract

Background and Objectives: Cut-off points for the triglyceride-glucose-body mass index (TyG-BMI) and the triglyceride-glucose-waist circumference index (TyG-WC) have been established for the assessment of insulin resistance (IR) only in the population of Asian women with polycystic ovary syndrome (PCOS). Therefore, the present study aimed to estimate the cut-off value for these indices discriminating the IR based on the homeostatic model assessment for insulin resistance (HOMA-IR) and sex hormone binding globulin (SHBG) levels established previously in Caucasian women with PCOS. Material and Methods: The medical records of 264 selected young adults (18–40 y.o.) Caucasian women with PCOS were the source of parameters: age, body weight, height, waist circumference, glucose, insulin, triglyceride, and SHBG levels, used for calculation of TyG-BMI and TyG-WC indices. The cut-off values for TyG-BMI and TyG-WC indices were calculated using receiver operating characteristic curve analysis. Results: The study group included 68 overweight (25.8%) and 62 overweight (23.4%) women. The empirical optimal cut-off values for TyG-BMI and TyG-WC indices corresponding to HOMA-IR values ≥ 2.1 were 233 and 735 [area under the curve (AUC) 85.1% and 86.7%, accuracy 0.814 and 0.784, sensitivity 66.3% and 67.3%, specificity 90.4% and 84.9%, PPV 80.2% and 72.5%, NPV 82.0% and 81.5%], respectively. The empirical optimal cut-off values for TyG-BMI and TyG-WC indices corresponding to SHBG levels < 41.5 nmol/L were 230 and 734 (AUC 79.5% and 77.1%, accuracy 0.735 and 0.723, Se 57.4% and 57.4%, Sp 87.3% and 85.2%, PPV 79.5% and 76.9%, NPV 70.4% and 69.9%), respectively. Conclusions: The cut-offs for the TyG-BMI and TyG-WC indices discriminating IR in young Caucasian women with PCOS were similar regardless of whether they are based on HOMA-IR values or SHBG levels.

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