Temporal Trends of the Prevalence of Abdominal Obesity and Metabolic Syndrome in Korean Children and Adolescents between 2007 and 2020

Background: The prevalence of obesity in children and adolescents is increasing worldwide, which is of concern because obesity can lead to various complications such as metabolic syndrome (MS). Waist circumference (WC) and waist-height ratio (WHtR) are useful indicators of abdominal obesity and MS. In this study, we investigate trends in the prevalence of abdominal obesity and MS using two different references.Methods: Data from the Korea National Health and Nutrition Examination Survey (2007 to 2020) were used. In total, 21,652 participants aged 2 to 18 years and 9,592 participants aged 10 to 18 years were analyzed for abdominal obesity and MS, respectively. The prevalence of abdominal obesity and that of MS were compared using the Korean National Growth Chart in 2007 (REF2007) and the newly published WC and WHtR reference values in 2022 (REF2022).Results: Both WC and WHtR showed an increasing trend. The prevalence of abdominal obesity was 14.71% based on REF2022, 5.85% points higher than that of 8.86% based on REF2007. MS based on REF2022 had a higher prevalence for both the National Cholesterol Education Program definition (3.90% by REF2007, 4.78% by REF2022) and the International Diabetes Federation definition (2.29% by REF2007, 3.10% by REF2022). The prevalence of both abdominal obesity and MS increased over time.Conclusion: The prevalence of abdominal obesity and MS increased in Korean children and adolescents from 2007 to 2020. When analyzed by REF2022, both abdominal obesity and MS showed higher prevalence rates than when using REF2007, indicating that previous reports were underestimated. Follow-up for abdominal obesity and MS using REF2022 is needed.