Background: Early intervention and diagnosis of Metabolic Syndrome (MetS) are crucial for preventing adult cardiovascular disease. However, the optimal indicator for identifying MetS in adolescent remains controversial.

Methods: In total,1408 Chinese adolescents and 3550 American adolescents aged 12-17 years were included. MetS was defined according to the modified version for adolescents based on Adult Treatment Panel III (NCEP-ATP III) criteria. Areas under the curve (AUC) and corresponding 95% confidence interval (95% CI) of 8 anthropometric/metabolic indexes, such as waist circumference (WC), body mass index (BMI), a body shape index (ABSI), waist triglyceride index (WTI), were calculated to illustrate their ability to differentiate MetS. Sensitivity analysis using the other MetS criteria was performed.

Results: Under the modified NCEP-ATP III criteria, WTI had the best discriminating ability in overall adolescents, with AUC of 0.922 (95% CI: 0.900-0.945) in Chinese and 0.959 (95% CI: 0.949-0.969) in American. In contrast, ABSI had the lowest AUCs. Results of sensitivity analysis were generally consistent for the whole Chinese and American population, with the AUC for WC being the highest under some criteria, but it was not statistically different from that of WTI.

Conclusions: WTI had relatively high discriminatory power for MetS detection in Chinese and American adolescents, but the performance of ABSI was poor.

Impact: While many studies have compared the discriminatory power of some anthropometric indicators for MetS, there are few focused on pediatrics. The current study is the first to compare the discriminating ability of anthropometric/metabolic indicators (WC, BMI, TMI, ABSI, WHtR, VAI, WTI, and TyG) for MetS in adolescents. WTI remains the optimal indicator in screening for MetS in adolescents. WC was also a simple and reliable indicator when screening for MetS in adolescents, but the performance of ABSI was poor. This study provides a theoretical basis for the early identification of MetS in adolescents by adopting effective indicators.