Metabolic Syndrome in Children and Adolescents: Is There a Universally Accepted Definition? Does it Matter?

The concept of metabolic syndrome (MetS) as a cluster of cardiovascular risk factors (obesity, altered glucose metabolism, dyslipidemia, and hypertension) has been around for more than 30 years. It is considered to be the result of complex interactions between centrally located fat, insulin resistance, subclinical inflammation, and other factors in genetically predisposed individuals. MetS diagnosis in adults has been linked to increased risk for cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). However, MetS in children and adolescents remains a controversial issue despite the extensive research in the field. It is still uncertain which definition should be used for its diagnosis in this age group, what is the clinical significance of such a diagnosis, and how reliably it can predict the future risk of developing CVD and T2D. Even if a child is diagnosed with MetS, management includes addressing each of the syndrome's components individually with weight loss and lifestyle modifications as the basic approach. Co-morbid conditions, such as nonalcoholic fatty liver disease, obstructive sleep apnea, and polycystic ovary syndrome should also be considered. It seems that MetS in children and adolescents should be used clinically as a conceptual framework for the identification of risk factors clustered around obesity and insulin resistance rather than a syndrome that needs to be diagnosed by measuring absolute "all-or-none" criteria.