Adipokines and Gamma-Glutamyl Transferase as Biomarkers of Metabolic Syndrome Risk in Mexican School-Aged Children

Background/Objectives: The prevalence of metabolic syndrome in children has been increasing, raising concerns about early detection and clinical management. Adipokines, which are secreted by adipose tissue, play a critical role in metabolic regulation and inflammation, while gamma-glutamyl transferase (GGT), as a liver enzyme, is linked to oxidative stress and metabolic disorders. The objective was to examine the association of circulating adipokines and GGT with metabolic syndrome risk in school-aged children from Northeast Mexico. Methods: A total of 140 children from 6 to 12 years of age in the state of Nuevo León, Mexico, participated in this study. Obesity was classified according to the BMI z-score by the World Health Organization (WHO, 2007), and metabolic syndrome was classified according to the International Diabetes Federation (IDF, 2007). Serum levels of leptin, adiponectin, TNF-α, IL-6, and GGT were measured. Statistical analysis was performed using the Student's t-test, simple linear regression analysis, and receiver operating characteristic (ROC) curve analysis. Results: Among the 140 participants, 60 children (43%) were classified as obese, and of those children with obesity, 55% were diagnosed with metabolic syndrome. Leptin was significantly associated with waist circumference (WC), systolic blood pressure (SBP), serum glucose, triglycerides, and HDL cholesterol (HDL-c). Adiponectin also showed significant associations with WC, SBP, serum triglycerides, and HDL-c. GGT was significantly correlated with WC and HDL-c, while IL-6 and TNF-α did not indicate significance. Associations were observed among leptin, adiponectin, and GGT, highlighting their combined role as potential markers for metabolic syndrome in children. The ROC curve analysis and Youden's index provided cut-off points for these biomarkers: leptin: 8.3665 ng/mL, adiponectin: 9.87 µg/mL, GGT: 17.8 U/L, IL-6 2.77 pg/mL, and TNF-α: 6.68 pg/mL; Conclusions: These findings emphasize the utility of leptin, adiponectin, and GGT as early biomarkers for identifying children with obesity who are at risk of developing metabolic syndrome.