Childhood Metabolic Syndrome

The metabolic syndrome, also known as “syndrome X,” describes a cluster of cardiovascular risk factors that have been shown to predict the development of cardiovascular disease and type 2 diabetes (1). Some suggest that the cluster is driven by the consequences of peripheral insulin resistance (2), whereas others believe that obesity-related inflammation is the culprit (3). Many putative molecular mechanisms can provide excellent explanations for both theories regarding the primary driving mechanism of the clustering of cardiovascular risk factors (4) and how each one accelerates atherogenesis (5). Yet teasing inflammation and peripheral insulin resistance apart in individual patients or even in large cohorts is difficult because of their coexistence and possible vicious exacerbation of each other. The general paradigm regarding the evolvement of the syndrome is that adipocyte dysfunction in some obese individuals who are genetically prone or exposed to specific environmental signals leads to peripheral insulin resistance and subclinical inflammation culminating in accelerated atherosclerosis and overt clinical manifestations (6). The clinical utility of defining this syndrome in children and adolescents has been debated, since some propose that from a clinical standpoint, addressing each component of the cluster individually has comparable clinical and predictive outcomes, whereas others suggest such definitions are inappropriate for the pediatric age group. This debate has important implications from an epidemiological and public health standpoint. Yet it is imperative to indicate that the underlying pathophysiology that leads to the typical metabolic milieu characteristic of individuals with obesity-driven peripheral insulin resistance and/or subclinical inflammation has common features in all ages and is postulated to be the “driving force” of the development of accelerated atherogenesis and altered glucose metabolism in susceptible individuals. Several definitions of the metabolic syndrome in children have been proposed by various research groups (7,8) and expert consensus (9), and the use of …