Isabel Rey Madeira

Ponto de corte do índice Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) avaliado pela curva Receiver Operating Characteristic (ROC) na detecção de síndrome metabólica em crianças pré-púberes com excesso de peso

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 definition of MS was adapted from that of the International Diabetes Federation. For each cut-off values for HOMA-IR, it was estimated sensibility and specificity 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 HOMAIR was 2,5, with sensitivity of 61% and specificity of 74%. CONCLUSIONS: HOMA-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.

Impact of obesity on metabolic syndrome components and adipokines in prepubertal children

OBJECTIVES 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). CONCLUSIONS 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.

Leptin as a predictor of metabolic syndrome in prepubertal children

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.

Hiperparatireoidismo primário associado a epifisiólise de cabeça do fêmur em adolescente

Primary hyperparathyroidism (PHP) is an uncommon disease in children and adolescents. The association between PHP and slipped capital femoral epiphysis is rare, and so far only four cases have been reported in the literature. Herein, we report a case of PHP due to a parathyroid adenoma, with several painful skeletal deformities and associated with slipped capital femoral epiphysis in an 18-year-old male patient. Laboratory evaluation showed: calcium of 13.6 mg/dL, parathyroid hormone of 1,524 pg/mL and alkaline phosphatase of 3,449 U/L. Deformities were caused by late diagnosis during the growth spurt, and this association is the result of combinations between metabolic and mechanical factors. The patient underwent parathyroidectomy and, in agreement with the literature, since the removal of the adenoma is followed by prompt resolution of the slipped capital femoral epiphysis we decided for a conservative approach. We observed improvement of the pain and normalization of calcium and parathyroid hormone levels.

Prevalência de obesidade e baixo peso ao nascer na pubarca precoce

The prevalence of obesity and presence of low birth weight (LBW) were evaluated retrospectively in 96 children with premature pubarche (PP), from which 90 cases of premature adrenarche were selected. Information on BW was found in 46 charts, and 5 prematures were excluded. Tanner stages, body mass index (BMI), presence of acanthosis nigricans and bone age (BA) were evaluated. Obesity was considered when BMI > the 95th percentile and overweight when BMI > the 85 and <95 percentiles. After a six-month follow-up, the BMI of 62 patients was reeva luated. The results showed that BA was higher than chronological age (7.9±1.97 x 7.0±1.7 years, p<0.001). 70% of the sample showed pubic hair in Tanner II stage in and 31% had acanthosis nigricans. The BW was 3,168.2±528.2g. In 12% of the cases a history of LBW was present, a result not different from the general population (10%). No correlation was found between BMI and BW. Obesity was observed in 31% and overweight in 19% of the cases. BMI increased after follow-up (18±3.0 x 19.4±3.5kg/m2, p=0.008). The prevalence of obesity was higher in children with PP than in the Brazilian population (31% x 15%, p<0.02). In conclusion, although excess weight is a common finding in PP, birth weight is normal. It is remarkable that these children must be stimulated to lose weight, since PP and obesity are associated with a higher risk for policystic ovary and plurimetabolic syndromes in adulthood.

Ultrasound as a method to evaluate the distribution of abdominal fat in obese prepubertal children and the relationship between abdominal fat and metabolic alterations

Abstract. Objective To evaluate, using ultrasound, the distribution of abdominal fat in obese prepubertal children, as well as its possible correlation with metabolic changes due to obesity. Materials and Methods This was a cross-sectional study of prepubescent children: 77 obese children (33 girls and 44 boys), with a mean age of 7.31 years; and 31 normal-weight children (17 girls and 14 boys), with a mean age of 7.32 years. In all of the children, abdominal wall thickness (AWT) and abdominal fat thickness (AFT) were measured by ultrasound. For the evaluation of the associated metabolic alterations, serum levels of glycemia, HDL cholesterol, triglycerides, and insulin were determined. Results The obese children presented with greater abdominal fat, predominantly greater AWT, without a significant gender-related difference in AWT or AFT. The homeostasis model assessment of insulin resistance (HOMA-IR) showed a significant direct correlation with AWT and AFT. Conclusion In obese prepubertal children, the AWT, as measured by ultrasound, was shown to be more closely related to the HOMA-IR than to the lipid metabolism or glycemia.

Physical fitness and activity, metabolic profile, adipokines and endothelial function in children

OBJECTIVES The prevalence of obesity is increasing. The aim of this study was to investigate if there is endothelial dysfunction in children with normal or excess weight, and whether the metabolic profile, adipokines, and endothelial dysfunction would be more strongly associated with physical fitness or with physical activity levels. METHOD Cross-sectional study involving children aged 5-12 years. The evaluation included venous occlusion plethysmography, serum levels of adiponectin, leptin and insulin, lipid profile, physical activity score (PAQ-C questionnaire), and physical fitness evaluation (Yo-Yo test). RESULTS A total of 62 children participated in this study. Based on the body mass index, 27 were eutrophic, 10 overweight and 25 obese. Triglycerides, LDL cholesterol, HOMA-IR, and leptin were higher in the obese and excess-weight groups compared to the eutrophic group (p<0.01). HDL cholesterol and adiponectin levels were higher in the eutrophic group compared to the obese and excess-weight groups (p<0.01). Flow-mediated vasodilation after hyperemia was higher in the eutrophic group in comparison to obese and excess-weight subjects (p<0.05). There was no difference in the physical activity levels among groups measured by PAQ-C. The Yo-Yo test was significantly associated with HDL cholesterol (rho=-0.41; p=0.01), and this association remained after adjusting for body mass index z-score (rho=0.28; p=0.03). CONCLUSION This study showed that endothelial dysfunction is already present in obese children, suggesting a predisposition to atherosclerotic disease. Moreover, HDL cholesterol levels were correlated with physical fitness, regardless of body mass index.