Context No universal waist circumference (WC) percentile cutoffs used have been proposed for screening central obesity in children and adolescents. Objective To develop international WC percentile cutoffs for children and adolescents with normal weight based on data from 8 countries in different global regions and to examine the relation with cardiovascular risk. Design and Setting We used pooled data on WC in 113,453 children and adolescents (males 50.2%) aged 4 to 20 years from 8 countries in different regions (Bulgaria, China, Iran, Korea, Malaysia, Poland, Seychelles, and Switzerland). We calculated WC percentile cutoffs in samples including or excluding children with obesity, overweight, or underweight. WC percentiles were generated using the general additive model for location, scale, and shape (GAMLSS). We also estimated the predictive power of the WC 90th percentile cutoffs to predict cardiovascular risk using receiver operator characteristics curve analysis based on data from 3 countries that had available data (China, Iran, and Korea). We also examined which WC percentiles linked with WC cutoffs for central obesity in adults (at age of 18 years). Main Outcome Measure WC measured based on recommendation by the World Health Organization. Results We validated the performance of the age- and sex-specific 90th percentile WC cutoffs calculated in children and adolescents (6-18 years of age) with normal weight (excluding youth with obesity, overweight, or underweight) by linking the percentile with cardiovascular risk (area under the curve [AUC]: 0.69 for boys; 0.63 for girls). In addition, WC percentile among normal weight children linked relatively well with established WC cutoffs for central obesity in adults (eg, AUC in US adolescents: 0.71 for boys; 0.68 for girls). Conclusion The international WC cutoffs developed in this study could be useful to screen central obesity in children and adolescents aged 6 to 18 years and allow direct comparison of WC distributions between populations and over time.

Growth references are useful in monitoring a child's growth, which is an essential part of child care. The aim of this paper is to provide updated growth references for Polish preschool children and to assess how well children in Poland match or diverge from the World Health Organization (WHO) growth standards/references and recent German height-for-age references. The height-, weight-, body mass index-for-age, and weight-for-height references were constructed with the LMS method using data from a recent, large, population-representative sample of 4,941 preschool children aged 3 to 6 years (the OLA study). In the case of boys, the third, 50th, and 97th height percentiles of new Polish and German references overlap almost completely, whereas the WHO growth standards/references percentiles are systematically lower. In the case of girls, comparison between the new Polish and German height references showed conformity on the third and 50th percentile, whereas body height values of the WHO standards/references are shorter. Polish children aged 3 to 6 years from for the nation representative sample, had significantly greater than zero mean z scores of height-, weight-, and BMI-for-age and weight-for-height, relative to the WHO growth standards/references. The number of children in the sample with height-for-age below −2 SD was significantly lower than expected and number of children with height-for-age above +2 SD was significantly higher than expected. Conclusion: The OLA study growth references can be recommended as national references for preschool children in Poland.

THRA mutations may be more common than expected. In patients with clinical symptoms of mild hypothyreosis without confirmation in endocrine studies, a molecular study of THRA defects is strongly recommended.

The growth pattern differs between patients with MPS I and II. It reflects the clinical severity of MPS and may assist in the evaluation of clinical efficacy of available therapies.

The observed high p.R152W carrier frequency in the Lithuanian population may indicate a possible founder effect in this region. The high prevalence of this mutation observed in the whole series, as well as the Slavic origin of the majority of patients homozygous for this mutation, suggest that p.R152W may be of Slavic, not Lithuanian origin. Resettlement of the Polish population after World War II resulted in dilution of the prevalence of carriers in Poland and a very low MPS VI incidence.