Examining metabolic syndrome definitions in overweight Hispanic youth: a focus on insulin resistance.

OBJECTIVE To examine the prevalence of the metabolic syndrome in overweight Hispanic youth according to 3 published pediatric definitions. Furthermore, the relationship of each definition to directly measured insulin resistance was examined. STUDY DESIGN We conducted a secondary data analysis of 218 overweight Hispanic youth with a family history of type 2 diabetes mellitus. The metabolic syndrome was defined as >/=3 of these criteria: elevated triglyceride level, low high-density lipoprotein cholesterol level, elevated blood pressure, abdominal obesity, and hyperglycemia. The cutoff points were derived from updated definitions of Cook et al,(1) Cruz et al,(2) and Weiss et al.(3) Insulin sensitivity was determined with the insulin-modified frequently sampled intravenous glucose tolerance test. RESULTS Prevalence of the metabolic syndrome ranged from 25.7% to 39%, with moderate to substantial agreement between definitions (kappa = 0.52-0.70). Regardless of definition, an inverse relationship between metabolic risk and insulin sensitivity was noted such that children with the metabolic syndrome had 51% to 60% lower insulin sensitivity compared with children without any risk factors (P </=.001 for all definitions). CONCLUSION The metabolic syndrome is prevalent in overweight Hispanic youth and may provide pediatricians with additional clinical insight for identifying the most metabolically at-risk children. Working toward a uniform and practical definition of the metabolic syndrome may improve its clinical implementation.