Polimorfismo N363S do gene do receptor de glucocorticoide: efeito sobre a adiposidade visceral medida pela tomografia computadorizada

OBJECTIVE: To verify whether N363S polymorphism of the glucocorticoid receptor-gene can be associated to visceral fat by CT scan in obese individuals, and the impact of this variant on metabolic profile. METHODS: The N363S variant was screened in 295 Brazilians, 195 were obese and 100 presented normal weight. Based on genotype, obese N363S SNP carriers were paired with obese wild-type subjects. This group was submitted to a CT scan and metabolic profile assessment. RESULTS: Ten subjects were found to be heterozygous for the variant (A/G genotype frequency 3.4%), 8 (4.1%) obese and 2 (2.0%) non-obese. No differences were reported for visceral adiposity area (145.8 ± 49.9 vs.147.7 ± 48.8 cm²; p = 0.92) based on CT scan results but N363S SNP carriers showed a proneness to unfavorable metabolic changes. CONCLUSION: The N363S polymorphism prevalence is low in the Brazilian population, although its presence may contribute to the worsening of individuals' metabolic profiles.OBJETIVO: Verificar se a presença do polimorfismo N363S do gene do receptor de glucocorticoide estaria associada, em indivíduos obesos, à presença de adiposidade visceral pela tomografia computadorizada, e sobre o impacto desta variante genética no perfil metabólico. MÉTODOS: A variante N363S do receptor do glicocorticoide foi verificada em um grupo de 295 indivíduos brasileiros, sendo 295 obesos e 100 com peso normal. Com base na genotipagem, os indivíduos obesos carreadores do polimorfismo N363S foram pareados com obesos normais. O grupo com polimorfismo foi submetido a exames de tomografia computadorizada abdominal e laboratoriais para a caracterização de seu perfil metabólico. RESULTADOS: Dez indivíduos eram heterozigotos para a variante AG (3,4%), sendo oito obesos (4,1%) e dois não-obesos (2%). Não foram encontradas diferenças na quantidade de adiposidade visceral (145,8 ± 49,9 versus 147,7 ± 48,8 cm²; p = 0,92) baseados no TC de abdômen. No entanto, os indivíduos carreadores do N363S SNP (single nucleotide polymorphism) apresentaram tendência a perfil metabólico desfavorável. CONCLUSÃO: O polimorfismo N363S do gene do receptor de glucocorticoide teve prevalência baixa na população estudada. A sua presença pode contribuir para a deterioração do perfil metabólico desses indivíduos

Augmented muscle vasodilatory responses in obese children with Glu27 beta(2)-adrenoceptor polymorphism

This study examined forearm vasodilatation during mental challenge and exercise in 72 obese children (OC; age = 10 +/- 0.1 years) homozygous with polymorphism in the allele 27 of the beta(2)-adrenoceptors: Gln27 (n = 61) and Glu27 (n = 11). Forearm blood flow was recorded during 3 min of each using the Stroop color-word test (MS) and handgrip isometric exercise. Baseline hemodynamic and vascular measurements were similar. During the MS, peak forearm vascular conductance was significantly greater in group Glu27 (Delta = 0.35 +/- 0.4 vs. 0.12 +/- 0.1 units, respectively, p = .042). Similar results were found during exercise (Delta = 0.64 +/- 0.1 vs. 0.13 +/- 0.1 units, respectively, p = .035). Glu27 OC increased muscle vasodilatory responsiveness upon the MS and exercise

Allelic variations in the vitamin D receptor gene, insulin secretion and parents' heights are independently associated with height in obese children and adolescents

Polymorphisms in the VDR gene were reported to be associated with variations in intrauterine and postnatal growth and with adult height, but also with other traits that are strongly correlated such as the BMI, insulin sensitivity, insulin secretion and hyperglycemia. Here, we assessed the impact of VDR polymorphisms on body height and its interactions with obesity- and glucose tolerance-related traits in obese children and adolescents. We studied 173 prepubertal (Tanner's stage 1) and 146 pubertal (Tanner's stages 2-5) obese children who were referred for a weight-loss program. Three single nucleotide polymorphisms were genotyped: rs1544410 (BsmI), rs7975232 (ApaI) and rs731236 (TaqI). BsmI and TaqI genotypes were significantly associated with height in pubertal children, but the associations did not reach statistical significance in prepubertal children. In stepwise regression analyses, the lean body mass, insulin secretion, BsmI or TaqI genotypes and the father's and the mother's height were independently and positively associated with height in pubertal children. These covariables accounted for 46% of the trait variance. The height of homozygous carriers of the minor allele of BsmI was 0.65 z-scores (4 cm) higher than the height of homozygous carriers of the major allele (P=.0006). Haplotype analyses confirmed the associations of the minor alleles of BsmI and TaqI with increased height. In conclusion, VDR genotypes were significantly associated with height in pubertal obese children. The associations were independent from the effects of confounding traits, such as the body fat mass, insulin secretion, insulin sensitivity and glucose tolerance. (C) 2012 Elsevier Inc. All rights reserved.FAPESP, BrazilFAPESP (Brazil)Societe Francophone du Diabete (SFD - Alfediam)Societe Francophone du Diabete (SFD Alfediam)Association Diabete Risque Vasculaire (ADRV), FranceAssociation Diabete Risque Vasculaire (ADRV), FranceCNPq, BrazilCNPq (Brazil

Binge eating symptoms, diet composition and metabolic characteristics of obese children and adolescents

This study aimed to determine the occurrence of symptoms of binge eating (BE) among children and adolescents seeking treatment for their obesity, as well as to evaluate their diet composition and metabolic characteristics. The Binge Eating scale (BES) was answered by 128 children and adolescents (10.77 +/- 2.04 years, BMI 29.15 +/- 4.98 kg/m(2), BMI Z score 2.28 +/- 0.46, 53.91% pubescent), who were classified into two subgroups-binge eaters (score greater than or equal to IS points) and non-binge eaters (score lower than 18 points). Anthropometric data, body composition and Tanner stages were collected and dietary evaluation conducted. Blood pressure was determined, and glucose, lipid profile and insulin assays were performed. insulin resistance was determined using HOMA-IR. BE symptoms were present in 39.06% of patients. Carbohydrate intake in diet composition was significantly higher among binge eaters. Children with BE did not demonstrate significant dissimilar metabolic characteristics when compared to their counterparts without BE. Therefore, BE seems to be a prevalent problem among children and adolescents seeking help for their obesity. When associated with obesity, this eating behaviour can influence macronutrient consumption through increased carbohydrate intake. Further research would be valuable to verify the reproducibility of these findings. (c) 2007 Elsevier Ltd. All rights reserved