First report on the validity of a continuous Metabolic Syndrome score as an indicator for Metabolic Syndrome in a national sample of paediatric population — the CASPIAN-III study Pierwsze doniesienie na temat wyniku oceny trafności ciągłego wskaźnika zespołu metabolicznego jako wskaźnika obecności zespołu metabolicznego przeprowadzonej w ogólnokrajowej próbie reprezentatywnej populacji pediatrycznej — badanie CASPIAN-III

Introduction: The aim of this study was to assess the validity of a continuous Metabolic Syndrome score (cMetS) in a nationally repre- sentative sample of Iranian children and to identify sex and age-specific optimal cut-off points of cMetS that are associated with MetS. Material and methods: This study was conducted among 3,254 schoolchildren aged 10-18 years. cMetS was derived by aggregating age and sex-standardised residuals of waist circumference (WC), mean arterial pressure (MAP), glucose, high density lipoprotein-cholesterol (HDL-C) and triglycerides (TG). To determine the optimal cut-off points of cMetS for predicting MetS, receiver operator characteristic (ROC) curve analysis was used with an estimation of the variables' sensitivity and specificity. Results: A graded relationship was documented between cMetS and the number of risk factors. Increasing mean values of cMetS with increasing numbers of components were apparent for both genders. The overall optimal cMetS cut-off point for predicting the presence of MetS was 2.93 (sen- sitivity = 92%, specificity = 91%, area of the curve = 0.96 (0.95-0.97)). The values for boys and girls were 2.97 and 3.26 respectively in the total study. Conclusion: This nationwide study confirmed the validity of the cMetS score in a population-based sample of Iranian children. cMetS appears to be an appropriate index for investigating the association between potential risk factors and MetS in epidemiological research in Iran. (Endokrynol Pol 2013; 64 (4): 278-284)