THE RELATIONSHIP BETWEEN THE TRIGLYCERIDE-GLUCOSE INDEX AND INSULIN RESISTANCE, INFLAMMATION, IRON METABOLISM AND MICRONUTRIENT PROFILE IN INDIVIDUALS WITH OBESITY
Introduction: The aim of this study was to compare metabolic parameters, inflammatory markers, indicators of iron metabolism and micronutrient levels among groups of obese individuals categorised according to the Triglyceride-Glucose (TyG) index, and to assess the relationship between the TyG index and these parameters. Methods: The data of 110 obese individuals with a BMI ≥ 30 kg/m² who presented at Eskişehir City Hospital were retrospectively analysed. Patients were divided into two groups according to the TyG index (Group 1: TyG < 8.85, n=48; Group 2: TyG ≥ 8.85, n=62). Demographic, anthropometric and laboratory data were compared. The diagnostic performance of the TyG index in predicting insulin resistance (HOMA-IR > 2.5) was assessed using ROC analysis. Results: In Group 2, BMI (37.8±4.5 vs. 32.4±2.1 kg/m²), waist circumference (114.2±12.6 vs. 98.6±8.4 cm), HOMA-IR (5.12±1.64 vs. 2.38±0.72), CRP (5.9±1.8 vs. 2.2±0.9 mg/L), ferritin (128±34 vs. 45±12 ng/mL) and uric acid (6.4±1.2 vs. 4.8±0.8 mg/dL) were significantly higher; serum iron (58±22 vs. 85±18 μg/dL), vitamin D (14.2±6.1 vs. 22.4±8.6 ng/mL), vitamin B12 (228±74 vs. 312±88 pg/mL), folate (7.2±2.6 vs. 9.8±3.1 ng/mL) and magnesium (1.75±0.3 vs. 2.08±0.2 mg/dL) were found to be significantly low. The strongest positive correlations with TyG were observed with HOMA-IR (r=+0.67) and CRP (r=+0.61). In the ROC analysis, the AUC value of the TyG index for predicting insulin resistance was 0.85 (p<0.001), and the optimal cut-off value was determined to be 8.85 (sensitivity 76.8%, specificity 81.2%). In the gender-based subgroup analysis, elevated uric acid levels were more pronounced in men (p=0.003 for interaction). Conclusion: The TyG index is a comprehensive metabolic marker that reflects insulin resistance, alongside inflammation, iron metabolism disorders and micronutrient deficiencies, in obese individuals. The use of the TyG index in the metabolic risk assessment of obese individuals may provide clinical benefits, particularly in the early detection of functional iron deficiency and micronutrient deficiencies.