Effects of perilipin (PLIN) gene variation on metabolic syndrome risk and weight loss in obese children and adolescents.

CONTEXT: Genetic polymorphisms at the perilipin (PLIN) locus have been investigated for their potential utility as markers for obesity and metabolic syndrome (MS). We examined in obese children and adolescents (OCA) aged 7-14 yr the association of single-nucleotide polymorphisms (SNP) at the PLIN locus with anthropometric, metabolic traits, and weight loss after 20-wk multidisciplinary behavioral and nutritional treatment without medication. DESIGN: A total of 234 OCA [body mass index (BMI = 30.4 +/- 4.4 kg/m(2); BMI Z-score = 2.31 +/- 0.4) were evaluated at baseline and after intervention. We genotyped four SNPs (PLIN1 6209T-->C, PLIN4 11482G-->A, PLIN5 13041A-->G, and PLIN6 14995A-->T). RESULTS: Allele frequencies were similar to other populations, PLIN1 and PLIN4 were in linkage disequilibrium (D' = 0.999; P < 0.001). At baseline, no anthropometric differences were observed, but minor allele A at PLIN4 was associated with higher triglycerides (111 +/- 49 vs. 94 +/- 42 mg/dl; P = 0.003), lower high-density lipoprotein cholesterol (40 +/- 9 vs. 44 +/- 10 mg/dl; P = 0.003) and higher homeostasis model assessment for insulin resistance (4.0 +/- 2.3 vs. 3.5 +/- 2.1; P = 0.015). Minor allele A at PLIN4 was associated with MS risk (age and sex adjusted) hazard ratio 2.4 (95% confidence interval = 1.1-4.9) for genotype GA and 3.5 (95% confidence interval = 1.2-9.9) for AA. After intervention, subjects carrying minor allele T at PLIN6 had increased weight loss (3.3 +/- 3.7 vs. 1.9 +/- 3.4 kg; P = 0.002) and increased loss of the BMI Z-score (0.23 +/- 0.18 vs. 0.18 +/- 0.15; P = 0.003). Due to group size, risk of by-chance findings cannot be excluded. CONCLUSION: The minor A allele at PLIN4 was associated with higher risk of MS at baseline, whereas the PLIN6 SNP was associated with better weight loss, suggesting that these polymorphisms may predict outcome strategies based on multidisciplinary treatment for OCA.

Angiotensin converting enzyme insertion/deletion polymorphism is associated with increased adiposity and blood pressure in obese children and adolescents.

BACKGROUND: The insertion/deletion polymorphism in the gene encoding the angiotensin-converting enzyme (ACE I/D) was associated with arterial hypertension and obesity in adults, but the data in children are scarce and yielded contrasting results. We assessed the impact of the ACE I/D on blood pressure and obesity related traits in a Brazilian cohort of obese children and adolescents. METHODS AND RESULTS: ACE I/D was genotyped in 320 obese children and adolescents (64% of girls) aged 7-16years, referred for a weight-loss program. We observed an association of the D-allele with blood pressure and with pre-hypertension/hypertension in boys (odds ratio 2.44, 95% C.I. 1.34-4.68, p=0.005 for a codominant model). The D-allele, insulin resistance and body fat mass had independent and additive effects and explained 14% of the variance of pre-hypertension/hypertension. The BMI, waist circumference, and body fat mass were significantly higher in DD/ID boys than in II boys (p<0.005). Allelic associations with obesity related traits were independent of the association with blood pressure. No genotype associations were observed in girls. CONCLUSIONS: The D-allele of the ACE I/D polymorphism was associated with arterial hypertension and with obesity related traits in boys, but not in girls, in a cohort of obese children and adolescents. These associations were independent of each other, as well as of the effects of other confounding traits such as insulin secretion, insulin sensitivity and glucose tolerance. Our results are in agreement with experimental evidences suggesting that the renin-angiotensin system plays a role in the regulation of visceral adipose tissue accumulation.

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 (4cm) 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.

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/m2, BMI Z score 2.28+/-0.46, 53.91% pubescent), who were classified into two subgroups--binge eaters (score greater than or equal to 18 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.

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.

Associação das variantes no ADIPOQ e concentrações séricas de adiponectina com alterações metabólicas em crianças e adolescentes obesos / Association between variants in ADIPOQ and adiponectina levels with metabolic features in obese children and adolescents

Adiponectina é um hormônio produzido e secretado em abundância pelo tecido adiposo, que regula o metabolismo melhorando a sensibilidade à insulina pela sua ação hepática e muscular. Diferentemente dos outros hormônios do tecido adiposo, seus níveis séricos diminuem à medida que aumenta a adiposidade e são inversamente correlacionados com a obesidade, resistência à insulina e síndrome metabólica. Variações no gene da adiponectina foram associadas a níveis de adiponectina, resistência à insulina e risco de diabetes. O objetivo deste estudo foi avaliar os níveis de adiponectina e as variantes no gene da adiponectina em crianças e adolescentes obesos e sem obesidade e correlacionar os achados às características antropométricas e metabólicas. Níveis de adiponectina sérica foram mais baixos em obesos e em indivíduos púberes. Em não obesos, os níveis de adiponectina a correlacionaram-se negativamente com a adiposidade, entretanto nos obesos, a resistência à insulina e o desenvolvimento puberal foram os fatores de diminuição dos níveis de adiponectina. Independentemente da adiposidade, da resistência à insulina e da puberdade, menores níveis de adiponectina (abaixo de 10g/mL) correlacionaram-se com maior risco de hipertrigliceridemia, baixo HDLC e síndrome metabólica. Na análise do gene da adiponectina foram identificados os SNPs -11391G>A (rs17300539), -11377C>G (rs822387) na região promotora, +45T>G (rs22411766) no exon 2, +349A>G (rs6773957) no intron 2, Y111H (rs17366743) e a mutação G90S no exon 3. O SNP-11391G>A estava em desequilíbrio de ligação de Hardy-Weinberg. As variantes Y111H e G90S estavam em forte desequilíbrio de ligação com SNP-11377C>G e G90S com SNP+45T>G. Foi observada associação do alelo G do SNP-11377 a maior adiposidade central e menores níveis séricos de glicose. Após construção dos haplótipos com os SNPs -11377C>G, +45T>G e +349A>G observou-se que a presença do alelo G do SNP-11377T>G associou-se a maior obesidade (GTA vs CTA)...

Adiponectin, present in high concentrations in blood circulation is produced in adipocytes. Adiponectin regulates insulin sensibility acting in liver and muscle. Plasma adiponectin decreases as adiposity increases and are inversely related to insulin resistance and metabolic syndrome. Variants in the adiponectin encoding gene have been associated with adiponectin levels, insulin resistance and type 2 diabetes. The aim of this study was to evaluate adiponectin levels, identify variants in the adiponectin gene and determine the relationship between adiponectin levels, genetic variances and anthropometric and metabolic features in obese and non-obese children and adolescents. We found lower adiponectin levels in obese and pubertal individuals. Adiponectin was inversely correlated to adiposity in non-obese. Instead, in obese youngsters, adiponectin levels were negatively associated to insulin resistance and pubertal state. Independent of adiposity, insulin resistance and pubertal stage, lower adiponectin levels (under 10g/mL) were related to lower HDLC, higher triglycerides and higher risk of having metabolic syndrome. We have identified 6 variants in adiponectin gene: SNPs -11391G>A (rs17300539), -11377C>G (rs822387) in promoter region, SNP+45T>G (rs22411766) in exon 2, SNP+349A>G (rs6773957) in intron 2 and SNP Y111H (rs17366743) and G90S mutation in exon 3. We found strong linkage disequilibrium between variant Y111H and -11377C>G SNP and between G90S mutation and -11377C>G and +45T>G SNPs. We detected an association between -11377C>G G allele and higher central adiposity and lower glucose levels. Haplotypes were constructed using the SNPs -11377C>G, +45T>G and +349A>G, and the results showed an association between -11377SNP G allele presence and higher adiposity (GTA vs CTA), whereas the presence of the recessive alleles of SNPs +45T>G and +349A>G was associated to a lower adiposity (GTA vs GGG). Hypertension was more frequent in the presence of +349A>G G...