RESUMOObjetivo: Estabelecer, entre os pontos de corte do índice homeostatic model assessment for insulin resistance (HOMA-IR), citados na literatura, o melhor em identifi car a síndrome metabólica (SM) em crianças com obesidade e sobrepeso. Métodos: Foram estudadas 140 crianças pré-púberes. A defi nição de SM foi adaptada da International Diabetes Federation. Para cada ponto de corte de HOMA-IR foram estimados sensibilidade e especifi cidade, tomandose como desfecho a SM. Uma curva receiver operating characteristic (ROC) foi construída com estes valores. Resultados: O grupo estudado constituiu-se de 106 crianças com obesidade (37 meninas e 69 meninos) e 34 com sobrepeso (19 meninas e 15 meninos), média de idade 6,5 ± 2,3 anos. A acurácia da curva ROC foi 72%, e o melhor ponto de corte foi 2,5, com sensibilidade 61% e especifi cidade 74%. Conclusões: O índice HOMA-IR pode ser útil para detectar a SM, e o ponto de corte 2,5 mostrou-se o melhor para crianças pré-pú-beres com obesidade e sobrepeso. Objective: To establish, among the cut-off values for the homeostatic model assessment for insulin resistance index (HOMA-IR) cited in the literature, the best in identifying metabolic syndrome (MS) in obese and overweight children. Methods: A total of 106 pre-pubertal children were studied. The defi nition of MS was adapted from that of the International Diabetes Federation. For each cut-off values for HOMA-IR, it was estimated sensibility and specifi city for MS. A receiver operating characteristic (ROC) curve was generated using these values. Results: The study included 106 obese (37 girls and 69 boys) and 34 overweight (19 girls and 15 boys) children aged 6,5 ± 2,3 years. The accuracy of the ROC curve was 72%, and the best cut-off value for HOMA-IR was 2,5, with sensitivity of 61% and specifi city of 74%. Conclusions: HO-MA-IR may be useful to detect MS and the cut-off 2,5 seems to be the best in obese and overweight pre-pubertal children.

Objective: To verify the impact of obesity on metabolic syndrome components and adipokine levels in prepubertal children. Methods:This cross-sectional study compared 30 obese, 31 overweight and 33 eutrophic children attending a university hospital-based outpatient pediatric clinic. Parameters assessed included glucose, serum lipids, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), glucose/insulin relation, adiponectin, and leptin. We compared the frequency of acanthosis nigricans and changes in waist, blood pressure, glucose, serum lipids, and insulin. The correlation between body mass index (BMI) z score and adipokines was evaluated.Results: Among obese children, there was a difference in the mean values of HDL cholesterol and adiponectin, whereas among the eutrophic children, there was a difference in the mean values of insulin, HOMA-IR, glucose/insulin relation, and leptin (p < 0.001). A difference was also observed regarding the frequency of acanthosis nigricans and alteration in waist and HDL cholesterol (p < 0.005) in the obese group. The BMI z score showed a positive correlation with leptin (p < 0.001) and a negative correlation with adiponectin (p = 0.001). In multiple linear regression, this correlation was maintained only for leptin; HDL-cholesterol correlated with adiponectin (p = 0.007) and HOMA-IR correlated with both variables (p < 0.05). Conclusion:These findings provide evidence of the influence of obesity on metabolic syndrome components and on adipokine levels in prepubertal children, indicating that these components may contribute to the beginning of cardiovascular diseases.J Pediatr (Rio J). 2009;85(3):261-268: Adiponectin, cardiovascular diseases, risk factors, homeostasis, body mass index, insulin, leptin, insulin resistance. ResumoObjetivo: Verificar o impacto da obesidade sobre os componentes da síndrome metabólica e sobre os níveis de adipocitoquinas em crianças pré-púberes. Métodos: Estudo transversal comparando 30 crianças obesas, 31com sobrepeso e 33 eutróficas, oriundas do ambulatório de pediatria geral de um hospital universitário, quanto às médias de glicose, lipídios séricos, insulina, HOMA-IR (homeostasis model assessment-insulin resistance), relação glicose/insulina, adiponectina e leptina. Compararam-se as frequências de acantose nigricans e das alterações de cintura, pressão arterial, glicose, lipídios séricos e insulina. Avaliou-se a correlação entre escore z de índice de massa corporal (IMC) e adipocitoquinas.Resultados: Houve diferença nas médias dos obesos, quanto a HDL-colesterol e adiponectina, e nas dos eutróficos, quanto a insulina, HOMA-IR, relação glicose/insulina e leptina (p < 0,001). O mesmo ocorreu em relação às frequências dos obesos quanto a acantose nigricans e alteração de cintura e HDL-colesterol (p < 0,005). O escore z de IMC se correlacionou positivamente com leptina (p < 0,001) e negativamente com adiponectina (p = 0,001). Na regressão linear múltipla, esta correlação se manteve apenas para leptina; o HDL-colesterol se correlaci...

Objective: Leptin has been suggested as a potential biomarker of cardiovascular risk. This paper aims to ascertain, based on a sample of prepubertal children, which serum leptin value best suited to identify metabolic syndrome (MS). Subjects and methods: This observational, cross-sectional study recruited children from the outpatient pediatrics clinic, with the purpose of validating serum leptin level cutoffs to identify MS. All obese and overweight children who met eligibility criteria were included in the study, as was a sample of normal-weight children. The sample underwent clinical assessment and blood fasting glucose, lipid profile, insulin, and leptin were measured. Sensitivity and specificity were estimated for each leptin measurement, using MS as the outcome. These values were used to construct a receiver operating characteristic (ROC) curve. The association between MS and leptin was assessed using logistic models to predict MS. Results: A total of 65 normal weight, 46 overweight, and 164 obese children were analyzed (160 boys, 115 girls; age: 93.7 ± 17.8 months). The most appropriate leptin cutoff was 13.4 ng/mL (sensitivity 67.6%; specificity 68.9%; accuracy 72.1%). The logistic model indicated that leptin levels above 13.4 ng/dL were significantly associated with MS and that, for every 1 ng/dL increase in leptin levels, the odds of MS increase by 3% (p = 0.002; OR 1.03; 95% CI 1.01-1.05). Conclusions: Leptin may be a useful biomarker of cardiovascular risk in prepubertal children, with an optimal cutoff of 13.4 ng/mL. Identification of potential new risk markers for cardiovascular disease in children could contribute to the development of preventive strategies.Arch Endocrinol Metab. 2017;61(1):7-13

ResumoDesde os anos pré-púberes, crianças com excesso de peso são expostas precocemente a fatores de risco cardiovascular que atuam de forma negativa no endotélio vascular e na íntima-média dos vasos, levando ao início da doença aterosclerótica nessa faixa etária. Esta revisão tem por objetivo trazer ao conhecimento dos profissionais de saúde a importância da identificação e da intervenção terapêutica precoces em crianças com excesso de peso, sabidamente em risco para a instalação da síndrome metabólica, na tentativa de evitar a evolução para doenças crônicas, em especial para as doenças cardiovasculares. Atualmente a obesidade atinge todas as faixas etárias da população e, assim como nos adultos, vem alcançando proporções epidêmicas nas crianças e adolescentes, já sendo considerada um dos desafios mais sérios de saúde pública no século XXI. Ao contrário do que se acreditava, que crianças obesas não apresentavam risco cardiovascular até atingirem a idade adulta, os estudos apontam que a aterosclerose se inicia na infância. A constatação de que o excesso de peso na infância e os fatores de risco a ele relacionados persistem até a vida adulta foi documentada em ao menos três grandes estudos de coorte: o Muscatine Study, o Cardiovascular Risk in Young Finns Study e o Bogalusa Heart Study. O tempo de exposição aos múltiplos fatores de risco nessa etapa da vida até a adultícia parece estar diretamente associado à morbimortalidade por doença cardiovascular. A demonstração de que as doenças cardiovasculares podem ter sua origem na infância leva à necessidade de que seus fatores de risco sejam amplamente investigados nesse período, com o objetivo de planejar intervenções cada vez mais precoces e possivelmente mais efetivas, reduzindo no futuro a morbimortalidade por doenças cardiovasculares.Descritores: Criança; Obesidade; Fatores de risco; Doenças cardiovasculares. AbstractPrepubertal children with excess weight are already exposed to cardiovascular risk factors that affect negatively the vascular endothelium and the intima media of the blood vessels inducing atherosclerotic changes. The objective of this review is to bring to the attention of health professionals the importance of early identification and intervention in children with excess weight, a known risk factor for metabolic syndrome, with the goal of preventing the development of chronic diseases, especially cardiovascular diseases. Obesity affects people of all ages and is considered an epidemic in children and adolescents, already the most important health challenge of the 21st century. Previously considered an adult disease, atherosclerosis is now believed to initiate during childhood. The proof that excess weight and its cardiovascular risk factors persist to adulthood came from at least three large cohort studies: the Muscatine Study, the Cardiovascular Risk in Young Finns Study, and the Bogalusa Heart Study. The length of time exposed to the multiple risk factors during this stage of life seems to be directly associated to cardiovascular disease morbimo...

Objective: Insulin resistance has a central role in the pathophysiology of cardiovascular atherosclerotic disease. Adipose tissue is of capital importance in view of its production of adipokines. The present study aims to determine the association of metabolic syndrome components, which constitute risk factors for cardiovascular atherosclerotic disease, and leptin and adiponectin with insulin resistance in prepubertal children. Methods: We conducted a cross-sectional study involving 197 children. Of these, 112 children were obese, 36 were overweight and 49 had normal weight. The association of sex, waist circumference, Acanthosis nigricans , age, BMI Z -score, serum lipids, leptin and adipocytokines with insulin resistance [defi ned as the homeostatic model assessment for insulin resistance (HOMA-IR) index higher than or equal to 2.5] was investigated using logistic regression. Results: There was positive association of sex (female), age, BMI Z-score, triglycerides and leptin with insulin resistance (p < 0.05). Conclusion: Among the conventional components of metabolic syndrome, the role of BMI Z-score and triglycerides stands out in insulin resistance of prepubertal children. Sex (female), age and leptin also showed to be of major importance.