Frequency of the metabolic syndrome in obese Spanish pediatric population

Objective: Obesity is associated with insulin-resistance (IR), type 2 diabetes (T2D) and a constellation of cardiovascular risk factors at the early years of life. These features define the so-called metabolic syndrome (MS). Aims: To assess the frequency of the MS among obese pediatric Spanish population and analyse the individual contribution and the predictive potential of individual components to the development of the syndrome. Patients and methods: A total of 429 patients, 220 boys and 209 girls, aged 4-18 years, with a body mass index of > 2 standard deviation scores for Spanish normative charts, were included in the study. Forty-seven percent were prepubertal and ten percent had Hispanic ethnicity. HbA1c, lipids, liver enzymes and uric acid levels were determined from blood and a standard 2-h oral glucose tolerance test was performed. MS was defined by the National Cholesterol Education Program's Adult Treatment Panel III criteria modified by Cook as having at least three features among: obesity, low high-density lipoprotein (HDL), hypertriglyceridemia, hypertension (HTA) or impaired glucose metabolism (IGM). We defined IR as homeostatic model assessment of IR index and/or fasting insulin levels > 95th centile of the control population. Results: Almost 18% of the patients had MS, with significantly higher frequency in Hispanic (32%) than in Caucasian (16%) population. There were no differences by sex or pubertal status. Prevalence of low HDL, HTA, hypertriglyceridemia and IGM were 2 7, 2 3, 16 and 7% respectively. No silent T2D was identified. According to International Obesity Task Force charts, 22% of the patients were overweight and not obese, but no differences in the frequency of individual features of MS between these two groups were observed. Among IR patients (35% of our population), the frequency of MS reached 28%. IR predicted the presence of MS independently from age and race. Conclusion: MS is present in 18% of our obese pediatric population. IR is closely associated with the components of MS and strongly predicts its development.