Using weight-for-age as a screening tool for metabolic syndrome in apparently healthy adolescents

Background: The increasing prevalence of metabolic syndrome (MetS) among adolescents necessitates a simple and easy-to-use screening tool. This study aimed to develop and validate a simple model based on age, sex, race, and weight-for-age or BMI-for-age to identify adolescents with MetS. Methods: A cross-sectional study of adolescents (aged 12–18 years) who participated in the American National Health and Nutrition Examination Survey (NHANES) was performed. Participants with pre-existing hypertension, diabetes or dyslipidemia were excluded. Data from 2005–2018 were randomly divided into training (70%) and validation (30%) sets. Anthropometric, demographic data, and MetS criteria were extracted. Results: The training group included 1974 adolescents (52% boys, median age 15 years), and the validation group included 848 adolescents (50% boys, median age 14 years). Both weight- and BMI-for-age demonstrated good discrimination ability in the training group (AUC = 0.897 and 0.902, respectively), with no significant difference between them (p = 0.344). Multivariable models showed similar discrimination ability. Therefore, weight-for-age was chosen and using Youden’s index, the 93rd weight-for-age percentile (SDS 1.5) was identified as the optimal cut-off value for MetS. Similar values were observed in the validation group. Conclusions: Among adolescents aged 12–18 years, weight-for-age percentiles are an easy-to-use primary screening indicator for the presence of MetS. Impact: The prevalence of metabolic syndrome in adolescents is increasing. An early detection screening tool is required to prevent related adulthood morbidity. Screening adolescents for metabolic syndrome is challenging. This study suggests the use of weight-for-age as a single criterion for primary screening of adolescents aged 12–18. Using weight-for-age as a single predictor of metabolic syndrome is expected to increase screening rates compared to using BMI-for-age, due to its simplicity.