To assess the accuracy of body mass index (BMI), Z score of the BMI, waist circumference, and waist-to-height ratio in selecting obese children with fasting metabolic impairments or impaired glucose tolerance.

In a cohort of 883 obese children and adolescents (age 8-18 years), we assessed the associations of anthropometric indices with traditional metabolic complications of obesity (impaired fasting glucose, impaired glucose tolerance, hypertension, high triglycerides, low high-density lipoprotein-cholesterol). The accuracy of anthropometric indices as markers of metabolic impairment was assessed by receiver operating characteristic analysis and the areas under the receiver operating characteristics curves (AUROCs) of anthropometric indices were compared with each other by the DeLong test.

BMI, Z score of the BMI, waist circumference, and waist-to-height ratio were associated with metabolic impairments but showed low to moderate accuracy in discriminating both single and clustered metabolic impairments. The AUROCs ranged from 0.55-0.70. The 4 anthropometric indices did not show significantly different AUROCs as predictors of clustered metabolic risk factors (all P values of DeLong tests: >.05).

Commonly used anthropometric indices are not satisfactory markers of metabolic comorbidity among obese children and adolescents and should not be adopted as screening tools for the metabolic assessment of this category of patients.