Circulating hepcidin was significantly and independently lower in type 2 diabetes. Metformin treatment is not associated with reductions in hepcidin but hypocaloric diet could be involved.

The aim of this study was to evaluate the metabolic syndrome (MetS) prevalence in adolescents using three different definitions for this age group. The evaluated sample consisted of 718 male and 743 female adolescents. Definitions by Cook et al., de Ferranti et al. and International Diabetes Federation (IDF) for adolescents were used to estimate the prevalence of MetS. The prevalence of MetS was 8.5, 2.5 and 1.2% by de Ferranti et al., Cook et al. and IDF definitions, respectively. High fasting glucose component had the lower prevalence whereas high triglycerides levels component was the most prevalent. In obese adolescents, the prevalence of MetS was higher. MetS classification in adolescents strongly depends on the definition chosen. Further research is required for the evaluation of the current definitions (multicentric studies), and for addition or design of new and useful criteria.

This study showed disturbing figures regarding cardiometabolic risk in the children based on comparisons with studies in adolescents. Further studies are needed to confirm the utility of the de Ferranti Mets definition in children.

Very few large studies in Latin America have evaluated the association between waist:height ratio (W-HtR) and cardiometabolic risk in children and adolescents. Further, multivariable analyses verifying the independence of located subcutaneous fat have not been conducted so far. The aim of this study was to evaluate the associations of W-HtR and waist circumference (WC) with metabolic syndrome abnormalities and high LDL-cholesterol levels in schooled adolescents before and after adjusting for trunk skinfolds and BMI. The sample consisted of 831 boys and 841 girls aged 10-17 years. Biochemical, blood pressure and anthropometrical variables were measured. Age-and sex-specific quartiles of W-HtR and WC were used in Poisson regression models to evaluate the associations. High WC values (highest quartile v. quartiles 1-3) were associated with high TAG levels in both sexes (prevalence ratio, boys: 2·57 (95 % CI 1·91, 3·44); girls: 1·92 (95 % CI 1·49, 2·47); P < 0·05), and with high blood pressure specifically in female adolescents (3·07 (95 % CI 1·58, 5·98); P < 0·05), independently of trunk skinfolds or BMI (P < 0·05). Associations of high WC with high fasting glucose (boys), low HDL-cholesterol and having at least two abnormalities did not remain significant in most of the adjustments for trunk skinfolds or BMI (P > 0·05). High W-HtR (highest quartile v. quartiles 1-3) was only independently associated with high TAG in female adolescents (1·99 (95 % CI 1·55, 2·56); P < 0·05). In conclusion, WC showed better association with cardiometabolic risk than W-HtR in the children of this study. This observation does not support W-HtR as a relevant adiposity marker for cardiovascular and metabolic risk in adolescence.

In the adolescents of this study, zinc intake could be more associated to a clustering of anthropometric, vascular, and metabolic alterations than to these alterations separately, and also it is inversely related to this clustering (MetS). However, studies in other populations are necessary to confirm and explain the finding of exclusive association zinc intake-MetS in male gender adolescents. Further research is required to explore biomarkers of physiological processes (antioxidant function, blood flow regulation, and epigenetic modulation dependent of zinc) in relation to zinc intake and MetS in pediatric and adult populations.