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

Body weight, metabolism and clock genes

Biological rhythms are present in the lives of almost all organisms ranging from plants to more evolved creatures. These oscillations allow the anticipation of many physiological and behavioral mechanisms thus enabling coordination of rhythms in a timely manner, adaption to environmental changes and more efficient organization of the cellular processes responsible for survival of both the individual and the species. Many components of energy homeostasis exhibit circadian rhythms, which are regulated by central (suprachiasmatic nucleus) and peripheral (located in other tissues) circadian clocks. Adipocyte plays an important role in the regulation of energy homeostasis, the signaling of satiety and cellular differentiation and proliferation. Also, the adipocyte circadian clock is probably involved in the control of many of these functions. Thus, circadian clocks are implicated in the control of energy balance, feeding behavior and consequently in the regulation of body weight. In this regard, alterations in clock genes and rhythms can interfere with the complex mechanism of metabolic and hormonal anticipation, contributing to multifactorial diseases such as obesity and diabetes. The aim of this review was to define circadian clocks by describing their functioning and role in the whole body and in adipocyte metabolism, as well as their influence on body weight control and the development of obesity

Variantes genéticos influenciando a efetividade das estratégias de perda de peso

Body weight excess has an increasingly high prevalence in the world. Obesity is a complex disease of multifactorial origin with a polygenic condition affected by environmental factors. Weight loss is a primary strategy to treat obesity and its morbidities. Weight changes through life depend on the interaction of environmental, behavioral and genetic factors. Interindividual variation of weight loss in response to different types of interventions (behavioral, caloric restriction, exercise, drug or surgery) has been observed. In this article, currently available data on the role of candidate gene polymorphisms in weight loss are reviewed. Even though control of weight loss by genotype was described in twin and family studies, it is premature to recommend use of genotyping in the design of therapeutic diets or drug treatment. Future studies will have to be large in order to assess the effects of multiple polymorphisms, and will have to control factors other than diet.A prevalência do excesso de peso cresce no mundo todo. De origem multifatorial, a obesidade é uma doença complexa, com condição poligênica afetada por fatores ambientais. A perda de peso é a estratégia primária utilizada para prevenir e tratar a obesidade bem como suas comorbidades. Mudanças de peso durante a vida dependem da interação entre fatores ambientais, comportamentais e genéticos. Observa-se grande variação da perda de peso entre indivíduos em resposta a diferentes modelos de intervenções (comportamentais, restrições da ingesta cálorica, exercícios físicos, drogas antiobesidade ou cirurgias). Este artigo é uma revisão atual da literatura disponível, que busca abordar o papel dos polimorfismos dos genes candidatos à obesidade e sua influência na perda de peso. Apesar da interação do genótipo na perda de peso corporal, descrita nos estudos de gêmeos e familiares, é prematuro recomendar o uso da genotipagem para estratégias de perda de peso. É necessário ampliar as pesquisas sobre os efeitos sinérgicos dos polimorfismos genéticos com coorte maior e associá-los não somente à restrição alimentar mas também às outras intervenções que auxiliam na perda de peso

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

Journal of Clinical Endocrinology and Metabolism

Texto completo: acesso restrito. p.2074-2078Activating mutations of the G protein genes have been associated with the development of several endocrine neoplasms. Such activating mutations, gip2, affecting the α-subunit of the Gαi2 protein were previously described by a single group in 30% of ovarian sex cord stromal tumors. Other activating mutations of the α-subunit of the Gs (gsp) have been identified in GH-secreting and nonfunctioning pituitary tumors, autonomous thyroid adenomas, and all affected McCune-Albright tissues, but not in sex cord stromal tumors. In the present study, we investigated the presence of gip2 and gsp mutations in 14 human sex cord stromal tumors. Six Leydig cell tumors (4 ovaries and 2 testes), 2 thecomas, 2 granulosa cell tumors, 3 androblastomas, and 1 gonadoblastoma (sex cord and germ cell) were included in this study. Genomic DNA was obtained from either fresh-frozen tumor tissues or paraffin-embedded sections and in some cases from blood samples. Using PCR, denaturing gradient gel electrophoresis, and direct sequencing, we detected 4 tumors (66.6%) with the gsp mutation (R201C) in our series of ovarian and testicular Leydig cell tumors. In contrast, no gip2 mutations were found in any of the sex cord stromal tumors studied. In conclusion, our findings suggest that the putative oncogene gsp may play a significant role in the molecular mechanism of these tumors

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