Visceral adiposity indicators and cardiovascular risk in hemodialytic patients

ABSTRACT Objective: Cardiovascular diseases represent the main cause of death in chronic kidney disease (CKD). We aimed to evaluate the prevalence and association of the hypertriglyceridemia-waist phenotype (HWP) and visceral adiposity index (VAI) with cardiometabolic risk factors (CR) in patients with CKD on hemodialysis (HD). Materials and methods: The study is based on a cross-sectional design with 265 HD patients in two cities in northeastern Brazil. The VAI was calculated considering the variables body mass index (BMI), waist circumference (WC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-c). HWP was defined as the concomitant elevation of WC and TG. The Poisson Regression Model with robust variance estimation was adjusted considering a hierarchical approach for explanatory variables. Prevalence ratios (PR) were also estimated. The level of significance adopted was 5%. Results: In our study HWP and VAI prevalence's were 29.82% and 58.49%, respectively. In the final model, there was an association between VAI and female gender (PR = 1.46; p < 0.0001) and high body fat (% BF) (PR = 1.33; p < 0.0019). HWP was associated with females (PR = 1.80; p = 0.002), alcohol consumption (PR = 1.58; p = 0.033), obesity (PR = 1.89; p = 0.0001), high %BF (PR = 1.76; p = 0.012) and reduced HDL-c (PR = 1.48; p = 0.035). Conclusion: The HWP stood out as the association with more CR factors, representing a promising method for tracking cardiometabolic risk in HD patients, mainly female.

Is it Possible to Easily Identify Metabolically Healthy Obese Women? / É Possível Identificar Facilmente Mulheres Obesas Metabolicamente Saudáveis?

Abstract Background: Obesity is recognized as a major risk factor for the development of several metabolic complications. However, some obese individuals have a favorable metabolic profile. Objective: The aim of this study was to identify an easy parameter for recognizing metabolically healthy obese (MHO) women. Methods: A total of 292 non-diabetic women with a body mass index (BMI) ≥ 30 kg/m2 were selected, and 239 composed the final cohort. We classified the participants according to their metabolic state determined by homeostasis model assessment (HOMA) into MHO or metabolically unhealthy obese (MUO). Both groups were compared regarding biochemical, anthropometric, and body composition characteristics. Results: The average age of the cohort was 43.9 ± 10.9 years and the average BMI was 37.2 ± 5.3 kg/m2. In total, 75.7% of the participants were classified as MHO by HOMA. A cutoff of 108.2 cm for waist circumference (WC) identified MHO participants with a sensitivity of 72.4% (95% confidence interval [CI]: 59.8-82.3%), specificity of 66.9% (95% CI: 59.71-73.3%), and negative likelihood ratio of 0.41 (95% CI: 0.36-0.47). Additionally, a visceral adiposity index cutoff value of 99.2 identified MHO women with a sensitivity of 89.7% (95% CI: 79.2-95.2%), specificity of 48.6% (95% CI: 41.4-55.9%), and negative likelihood ratio of 0.21 (95% CI: 0.15-0.30). Conclusion: Women classified as MHO exhibited smaller WC measurements and lower body fat percentages, as well as lower blood glucose and insulin levels. WC emerged as an easy parameter for identifying MHO women.

Resumo Fundamento: A obesidade é reconhecida como um fator de risco importante no desenvolvimento de várias complicações metabólicas. Porém, alguns indivíduos obesos apresentam um perfil metabólico favorável. Objetivo: O objetivo do presente estudo foi identificar um parâmetro fácil para reconhecer mulheres obesas metabolicamente saudáveis (OMS) Métodos: Foram selecionadas 292 mulheres não diabéticas com índice de massa corporal (IMC) ≥ 30 kg/m2 e a coorte final foi composta de 239. De acordo com o estado metabólico determinado pelo modelo de avaliação da homeostase (HOMA), as participantes foram classificadas como obesas metabolicamente saudáveis (OMS) ou obesas metabolicamente não saudáveis (OMNS). Compararam-se ambos os grupos quanto às características bioquímicas, antropométricas e de composição corporal. Resultados: A idade média da coorte foi de 43,9 ± 10,9 anos e o IMC médio foi 37,2 ± 5,3 kg/m2. No total, 75,7% das participantes foram classificadas como OMS pelo HOMA. O ponto de corte para a circunferência da cintura (CC) de 108,2 identificou mulheres OMS com sensibilidade de 72,4% (intervalo de confiança [IC] de 95%: 59,8-82,3%), especificidade de 66,9% (IC 95%: 59,71-73,3%) e razão de verossimilhança negativa (RVN) de 0,41 (IC 95%: 0,36-0,47). Adicionalmente, o ponto de corte de 99,2 para o índice de adiposidade visceral (IAV) identificou mulheres OMS com sensibilidade de 89,7% (IC 95%: 79.2-95.2%), especificidade de 48,6% (IC 95%: 41,4-55,9%) e RVN de 0,21 (IC 95%: 0.15-0.30). Conclusões: Mulheres classificadas como OMS apresentaram menor CC, menor percentual de gordura corporal e menores níveis séricos de glicose e de insulina. A CC foi identificada como um parâmetro fácil para identificar mulheres OMS.

Visceral adiposity index and triglyceride/high-density lipoprotein cholesterol ratio in hypogonadism

ABSTRACT Background Cardiometabolic risk is high in patients with hypogonadism. Visceral adiposity index (VAI) and triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio are the practical markers of atherosclerosis and insulin resistance and independent predictors of cardiaovascular risk. To date, no study has evaluated VAI levels and TG/HDL-C ratio in hypogonadism. Subjects and methods A total of 112 patients with congenital hypogonadotrophic hypogonadism (CHH) (mean age, 21.7 ± 2.06 years) and 124 healthy subjects (mean age, 21.5 ± 1.27 years) were enrolled. The demographic parameters, VAI, TG/HDL-C ratio, asymmetric dimethylarginine (ADMA), high-sensitivity C-reactive protein (hs-CRP), and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured for all participants. Results The patients had higher total cholesterol (p = 0.04), waist circumference, triglycerides, insulin, and HOMA-IR levels (p = 0.001 for all) than the healthy subjects. VAI and ADMA and TG/HDL-C levels were also higher in patients than in healthy subjects (p < 0.001 for all). VAI was weakly correlated with ADMA (r = 0.27, p = 0.015), HOMA-IR (r = 0.22, p = 0.006), hs-CRP (r = 0.19, p = 0.04), and total testosterone (r = −0.21, p = 0.009) levels, whereas TG/HDL-C ratio was weakly correlated weakly with ADMA (r = 0.30, p = 0.003), HOMA-IR (r = 0.22, p = 0.006), and total testosterone (r = −0.16, p = 0.03) levels. Neither VAI nor TG/HDL-C ratio determined ADMA, HOMA-IR, and hs-CRP levels. Conclusions The results of this study demonstrate that patients with hypogonadism have elevated VAI and TG/HDL-C ratio. These values are significantly correlated with the surrogate markers of endothelial dysfunction, inflammation, and insulin resistance. However, the predictive roles of VAI and TG/HDL-C ratio are not significant. Prospective follow-up studies are warranted to clarify the role of VAI and TG/HDL-C ratio in predicting cardiometabolic risk in patients with hypogonadism.

Hypomagnesemia and its relation with chronic low-grade inflammation in obesity / Hipomagnesemia e sua relação com a inflamação crônica de baixo grau na obesidade

Summary Introduction: The accumulation of visceral fat in obesity is associated with excessive production of proinflammatory adipokines, which contributes to low-grade chronic inflammation state. Moreover, the literature has shown that mineral deficiency, in particular of magnesium, has important role in the pathogenesis of this metabolic disorder with relevant clinical repercussions. Objective: To bring updated information about the participation of hypomagnesemia in the manifestation of low-grade chronic inflammation in obese individuals. Method: Articles published in PubMed, SciELO, LILACS and ScienceDirect, using the following keywords: "obesity," "magnesium" and "low grade inflammation." Results: Scientific evidence suggests that magnesium deficiency favors the manifestation of low-grade chronic inflammation in obese subjects. Conclusion: From literature data, it is evident the participation of magnesium through biochemical and metabolic reactions in protecting against this metabolic disorder present in obesity.

Resumo Introdução: O acúmulo de gordura visceral na obesidade está associado à produção excessiva de adipocinas pró-inflamatórias, o que contribui para o estado de inflamação crônica de baixo grau. A literatura também tem mostrado que a deficiência de minerais, em particular do magnésio, possui papel importante na patogênese desse distúrbio metabólico com repercussões clínicas relevantes. Objetivo: Trazer informações atualizadas sobre a participação da hipomagnesemia na inflamação crônica de baixo grau em indivíduos obesos. Método: Bases de dados Pubmed, SciELO, Lilacs e ScienceDirect, utilizando as palavras-chave: "obesity", "magnesium" e "low grade inflammation". Resultados: As evidências científicas sugerem que a deficiência de magnésio favorece a manifestação da inflamação crônica de baixo grau em indivíduos obesos. Conclusão: É evidente a participação do magnésio, por meio de reações bioquímicas e metabólicas, na proteção contra esse distúrbio metabólico presente na obesidade.

High-fat diet or low-protein diet changes peritoneal macrophages function in mice

BACKGROUND: Obesity and protein malnutrition are major food problems nowadays, affecting billions of people around the world. The nutrition transition that has occurred in recent decades is changing the nutritional profile, reducing malnutrition and increasing the percentage of obese people. The innate immune response is greatly influenced by diet, with significant changes in both malnutrition and obesity. Therefore, we investigate the effects of protein malnutrition and obesity in nutritional and immunological parameters in mice. RESULTS: Peritoneal macrophages of malnourished animals showed reduced functions of adhesion, spreading, and fungicidal activity; production of hydrogen peroxide and nitric oxide were lower, reflecting changes in the innate immune response. However, the high-fat animals had macrophage functions slightly increased. CONCLUSIONS: Animals subjected to low-protein diet have immunosuppression, and animals subjected to high-fat diet increased visceral adipose tissue and the presence of an inflammatory process with increased peritoneal macrophage activity and similar systemic changes to metabolic syndrome.

Estrogen deficiency in ovariectomized rats: can resistance training re-establish angiogenesis in visceral adipose tissue?

OBJECTIVE: The purpose of this study was to investigate the effects of resistance training on angiogenesis markers of visceral adipose tissue in ovariectomized rats. METHOD: Adult Sprague-Dawley female rats were divided into four groups (n=6 per group): sham-sedentary, ovariectomized sedentary, sham-resistance training and ovariectomized resistance training. The rats were allowed to climb a 1.1-m vertical ladder with weights attached to their tails and the weights were progressively increased. Sessions were performed three times per week for 10 weeks. Visceral adipose tissue angiogenesis and morphology were analyzed by histology. VEGF-A mRNA and protein levels were analyzed by real-time PCR and ELISA, respectively. RESULTS: Ovariectomy resulted in higher body mass (p=0.0003), adipocyte hypertrophy (p=0.0003), decreased VEGF-A mRNA (p=0.0004) and protein levels (p=0.0009), and decreased micro-vascular density (p=0.0181) in the visceral adipose tissue of the rats. Resistance training for 10 weeks was not able to attenuate the reduced angiogenesis in the visceral adipose tissue of the ovariectomized rats. CONCLUSION: Our findings indicate that the resistance training program used in this study could not ameliorate low angiogenesis in the visceral adipose tissue of ovariectomized rats.

Esteatosis hepática, grasa visceral y alteraciones metabólicas, en individuos con sobrepeso/obesidad aparentemente sanos / Hepatic steatosis, visceral fat and metabolic alterations in apparently healthy overweight/obese individuals

La observación clínica indica que muchos obesos no presentan alteraciones metabólicas importantes, por lo que el objetivo del presente estudio fue comprobar si el sobrepeso/obesidad (SP/OB) simple, no asociado a otros factores de riesgo, se acompañaba de alteraciones metabólicas; o si estaba presente el fenómeno conocido como “paradoja de la obesidad”. A 30 individuos aparentemente sanos de Maracaibo, Venezuela, entre 20 y 59 años de edad, e índice de masa corporal (IMC) superior a 25 kg/m², y a un grupo control de 11 individuos con IMC inferior a 25 kg/m², se les realizó una historia clínica, medida de parámetros antropométricos, determinaciones basales de glicemia, insulina y lípidos, medición ultrasonográfica para esteatosis hepática y ultrasonografía e impedancia bioeléctrica para estimar la grasa visceral. El estudio demostró que solo en un tercio de los individuos con SP/OB, con elevado IMC y circunferencia de cintura (CC), se encontraron concentraciones elevadas de insulina, HOMA-IR y triglicéridos. A pesar de ello, la presencia de esteatosis hepática fue muy elevada (91%) en el grupo SP/OB, si se compara con 9% en el grupo control. La grasa visceral, en el grupo control, estuvo asociada a la CC y a la glicemia; sin embargo, no se relacionó con el IMC, insulina, HOMA-IR o HDLc; mientras que en el grupo SP/OB, aunque estadísticamente elevada en relación al grupo control, reveló una pérdida de estas asociaciones. Los resultados resaltan la importancia de investigar más la presencia de esteatosis hepática en los individuos con SP/OB, que la estimación de la grasa visceral, para identificar sujetos con alto riesgo cardiometabólico.

Clinical observation indicates that many obese individuals do not display important metabolic alterations. Consequently, the objective of this study was to establish whether simple obesity, non concurrent with other important risk factors, was associated with metabolic alterations; or if the phenomenon known as “obesity paradox” was present. A clinical history, measurements of anthropometric and metabolic parameters and estimation of hepatic steatosis and visceral fat, were determined in 30, apparently healthy, individuals from Maracaibo, Venezuela, between 20 and 59 years of age and a body mass index (BMI) above 25 kg/m²,and compared to a lean control group of 11 individuals with BMI less than 25 kg/m². The study demonstrated that only one third of overweight/obese individuals (OW/OB), with high body mass index (BMI) and waist circumference (WC), presented elevated values of insulin, HOMA-IR and triglycerides. Nevertheless, the presence of hepatic steatosis was elevated in the OW/OB group (91%) vs. 9% in the control group. The visceral fat in the lean control group was associated with both, WC and glycemia; however, it was not related to the BMI or insulin, HOMA-IR and HDLc. The visceral fat in the OW/OB group, although elevated in relation to the lean group, revealed a loss of these associations. In the OW/OB it was the BMI that was associated with insulin and HOMA-IR. The results emphasize the importance of investigating for the presence of hepatic steatosis, rather than visceral fat, in individuals with OW/OB, to identify subjects with high cardiometabolic risk.

Cortisol: the villain in Metabolic Syndrome? / Cortisol: o vilão na Síndrome Metabólica?

Objective This article reviews the state of the art regarding the association between glucocorticoid actions and both obesity and insulin resistance, two main features of the metabolic syndrome. Methods A methodological assessment of the literature on PubMed and SciELO databases was conducted by using the following terms: stress, metabolic syndrome, glucocorticoids, obesity, insulin resistance, hypothalamic-pituitary-adrenal-axis and 11β-hydroxysteroid dehydrogenase. Results Chronic stress, mainly through hypothalamic-pituitary-adrenal axis dysregulation, promotes the accumulation of visceral fat. Reciprocally, obesity promotes a systemic low-grade inflammation state, mediated by increased adipokine secretion, which can chronically stimulate and disturb stress system. This vicious cycle, probably initiated by visceral adipose tissue dysfunction, might be the trigger for the development of metabolic syndrome. Conclusion Given the strong evidences linking glucocorticoid release, obesity and type 2 diabetes, better understanding of the mechanisms underlying this connection might be useful for prevention and treatment of the metabolic syndrome. .

Objetivo Este artigo revê o estado da arte relativamente à associação entre as ações dos glicocorticoides e a obesidade e a resistência à insulina, dois dos principais componentes da síndrome metabólica. Métodos Uma revisão da literatura nas bases de dados PubMed e SciELO foi realizada usando os seguintes termos: estresse, síndrome metabólica, glicocorticoides, obesidade, resistência à insulina, eixo hipotálamo-hipófise-suprarrenal e 11β-hidroxiesteróide desidrogenase. Resultados O estresse crônico, principalmente através da desregulação do eixo hipotálamo-hipófise-suprarrenal, promove a acumulação de gordura visceral. Reciprocamente, a obesidade promove um estado inflamatório sistêmico de baixo grau, mediado por alterações na secreção de adipocinas, que cronicamente podem estimular e perturbar o sistema de estresse. Esse círculo vicioso, provavelmente iniciado pela disfunção do tecido adiposo visceral, pode ser o mecanismo primário que conduz ao desenvolvimento da síndrome metabólica. Conclusão Um conhecimento mais aprofundado sobre os mecanismos envolvidos na associação entre a liberação de glicocorticoides, a obesidade e o diabete tipo 2 pode ser útil na prevenção e tratamento da síndrome metabólica. .

Enhanced A-FABP expression in visceral fat: potential contributor to the progression of NASH

BACKGROUND/AIMS: Adipose tissue is an active endocrine organ that secretes various metabolically important substances including adipokines, which represent a link between insulin resistance and nonalcoholic steatohepatitis (NASH). The factors responsible for the progression from simple steatosis to steatohepatitis remain elusive, but adipokine imbalance may play a pivotal role. We evaluated the expressions of adipokines such as visfatin, adipocyte-fatty-acid-binding protein (A-FABP), and retinol-binding protein-4 (RBP-4) in serum and tissue. The aim was to discover whether these adipokines are potential predictors of NASH. METHODS: Polymerase chain reaction, quantification of mRNA, and Western blots encoding A-FABP, RBP-4, and visfatin were used to study tissue samples from the liver, and visceral and subcutaneous adipose tissue. The tissue samples were from biopsy specimens obtained from patients with proven NASH who were undergoing laparoscopic cholecystectomy due to gallbladder polyps. RESULTS: Patients were classified into two groups: NASH, n=10 and non-NASH, n=20 according to their nonalcoholic fatty liver disease Activity Score. Although serum A-FABP levels did not differ between the two groups, the expressions of A-FABP mRNA and protein in the visceral adipose tissue were significantly higher in NASH group than in non-NASH group (104.34 vs. 97.05, P<0.05, and 190.01 vs. 95.15, P<0.01, respectively). Furthermore, the A-FABP protein expression ratio between visceral adipose tissue and liver was higher in NASH group than in non-NASH group (4.38 vs. 1.64, P<0.05). CONCLUSIONS: NASH patients had higher levels of A-FABP expression in their visceral fat compared to non-NASH patients. This differential A-FABP expression may predispose patients to the progressive form of NASH.

Abdominal adiposity, insulin and bone quality in young male rats fed a high-fat diet containing soybean or canola oil

OBJECTIVES: A low ratio of omega-6/omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fatty diets can induce obesity. Our objective was to evaluate intra-abdominal adiposity, insulin, and bone growth in rats fed a high-fat diet containing low ratios of omega-6/omega-3 provided in canola oil. METHODS: After weaning, rats were grouped and fed either a control diet (7S), a high-fat diet containing soybean oil (19S) or a high-fat diet of canola oil (19C) until they were 60 days old. Differences were considered to be significant if p<0.05. RESULTS: After 60 days, the 19S and 19C groups showed more energy intake, body density growth and intraabdominal fat mass. However, the 19S group had a higher area (200 percent) and a lower number (44 percent) of adipocytes, while the 7S and 19C groups did not differ. The serum concentrations of glucose and insulin and the insulin resistance index were significantly increased in the 19C group (15 percent, 56 percent, and 78 percent, respectively) compared to the 7S group. Bone measurements of the 19S and 19C groups showed a higher femur mass (25 percent) and a higher lumbar vertebrae mass (11 percent) and length (5 percent). Computed tomography analysis revealed more radiodensity in the proximal femoral epiphysis and lumbar vertebrae of 19C group compared to the 7S and 19S groups. CONCLUSIONS: Our results suggest that the amount and source of fat used in the diet after weaning increase body growth and fat depots and affect insulin resistance and, consequently, bone health.

Beneficial effects of exercise training (treadmill) on insulin resistance and nonalcoholic fatty liver disease in high-fat fed C57BL/6 mice

C57BL/6 mice develop signs and symptoms comparable, in part, to the human metabolic syndrome. The objective of the present study was to evaluate the effects of exercise training on carbohydrate metabolism, lipid profile, visceral adiposity, pancreatic islet alterations, and nonalcoholic fatty liver disease in C57BL/6 mice. Animals were fed one of two diets during an 8-week period: standard (SC, N = 12) or very high-fat (HF, N = 24) chow. An exercise training protocol (treadmill) was then established and mice were divided into SC and HF sedentary (SC-Sed, HF-Sed), exercised groups (SC-Ex, HF-Ex), or switched from HF to SC (HF/SC-Sed and HF/SC-Ex). HF/HF-Sed mice had the greatest body mass (65 percent more than SC/SC-Sed; P < 0.0001), and exercise reduced it by 23 percent (P < 0.0001). Hepatic enzymes ALP (+80 percent), ALT (+100 percent) and AST (+70 percent) were higher in HF/HF mice than in matched SC/SC. Plasma insulin was higher in both the HF/HF-Sed and HF/SC-Sed groups than in the matched exercised groups (+85 percent; P < 0.001). Pancreatic islets, adipocytes and liver structure were greatly affected by HF, ultimately resulting in islet â-cell hypertrophy and severe liver steatosis. The HF group had larger islets than the SC/SC group (+220 percent; P < 0.0001), and exercise significantly reduced liver steatosis and islet size in HF. Exercise attenuated all the changes due to HF, and the effects were more pronounced in exercised mice switched from an HF to an SC diet. Exercise improved the lipid profile by reducing body weight gain, visceral adiposity, insulin resistance, islet alterations, and fatty liver, contributing to obesity and steatohepatitis control.

Metabólitos séricos da vitamina D não se correlacionam com pressão arterial em adolescentes / There are no association between vitamin D metabolites and blood pressure in adolescents

OBJETIVO: O objetivo deste estudo foi avaliar a associação entre o estado nutricional da vitamina D, a adiposidade e a pressão arterial (PA) em adolescentes. MÉTODOS: Foi realizada avaliação antropométrica, da composição corporal, da ingestão alimentar, de medidas bioquímicas e aferição da PA de 205 adolescentes, com média de idade de 18,2 anos. RESULTADOS: Destes, 12,19% apresentaram PA elevada. O nível sérico médio da 25OHD foi 29,2(0,8) ng/mL, e 62% dos adolescentes apresentaram insuficiência de vitamina D. Não foi encontrada correlação significativa entre a PAS e a PAD com a 25OHD e a 1,25(OH)2D. Houve correlação negativa entre a PAD com os níveis séricos de adiponectina, e tanto a PAS quanto a PAD apresentaram correlação positiva com a circunferência da cintura em ambos os sexos. CONCLUSÃO: Não houve relação entre os níveis séricos de vitamina D e a PA. Porém, a gordura visceral apresenta risco potencial para elevação da PA em adolescentes.

OBJETIVES: The purpose of this study was to evaluate the relationships between serum levels of vitamin D and blood pressure (BP) in adolescents. METHODS: The anthropometric measurements, body composition, dietary intake, blood pressure and biochemical measurements was undertaken. RESULTS: Two hundred and five adolescents, 106 boys and 99 girls, mean aged 18.2 years old, participate of the study. Elevated BP was observed in 12.19% of the adolescents. Mean 25OHD concentration was 29.2(0.8) ng/mL. Vitamin D insufficiency was observed in 62% of adolescents. There were no correlation between systolic and diastolic BP with 25OHD and 1,25(OH)2D concentration. An inverse correlation between adiponectin and diastolic BP was observed and positive significant correlation was observed between waist circumference with systolic and diastolic BP in both boys and in girls. In conclusion, no relationships between vitamin D levels and blood pressure were observed. CONCLUSION: However, the intra-abdominal adiposity offers potential risk to BP elevation in adolescents.

Adipose tissue at the crossroads in the development of the metabolic syndrome, inflammation and atherosclerosis / Tecido adiposo na encruzilhada no desenvolvimento da síndrome metabólica, inflamação e aterosclerose

The authors analyze insulin resistance, the metabolic syndrome and endothelial dysfunction as consequence of a common antecedent, a low grade inflammation, indicating that in obesity there is a chronically activated inflammatory state of the adipose tissue. Furthermore, the inflammatory signaling is discussed according to the adipose tissue depot, visceral or subcutaneous.

Os autores analisam a resistência à insulina, a síndrome metabólica e a disfunção endotelial como consequência de um antecedente comum, a inflamação de baixo nível, o que mostra que a obesidade é um estado inflamatório cronicamente ativado do tecido adiposo. Discute-se, aqui, a sinalização inflamatória de acordo com a localização do tecido adiposo subcutâneo ou visceral.

The N363S polymorphism in the glucocorticoid receptor gene: effects on visceral fat assessed by abdominal computed tomography / 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 percent), 8 (4.1 percent) obese and 2 (2.0 percent) 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 por cento), sendo oito obesos (4,1 por cento) e dois não-obesos (2 por cento). 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.

Microcirculation in obesity: an unexplored domain

Obesity is traditionally linked to diabetes and cardiovascular diseases. Very recent experimental, clinical and epidemiological, sometimes provocative, data challenge this automaticity by showing that not the amount but the distribution of fat is the important determinant. Moderate abdominal fat accumulation may thus be more harmful than even consequent overweight. In view of the worldwide burden of obesity, factors leading to it in children and young adults must urgently be identified. Since obesity is a very complex cardiometabolic situation, this will require to focus investigations on uncomplicated obese subjects and adequate animal models. The recent discovery of intergenerational transmissions of obesity risk factors and also the key role played by gestational and perinatal events (epigenetic factors) give rise to completely new concepts and research avenues. Considering the potential close relationship between microcirculation and tissue metabolism, demonstrations of structural and/or functional abnormalities in microvascular physiology very early in life of subjects at risk for obesity might provide a solid basis for further investigations of such links. Microcirculation(arterioles, capillaries and venules) is conceivably a key compartment determining over one or several decades the translation of genetic and epigenetic factors into fat accumulation. Available animal models should serve to answer this cardinal question.

A obesidade é tradicionalmente associada ao diabetes e adoenças cardiovasculares. Dados muito recentes, algumasvezes provocativos, experimentais, clínicos e epidemiológicos questionam essa associação automática mostrando que não é a quantidade, mas a distribuição de gordura que é o determinante importante. O acúmulo moderado de gordura abdominal pode ser mais danoso que o conseqüente sobrepeso. Tendo em vista o aumento mundial da obesidade, fatores que levam a isso em crianças e adultos jovens devem ser urgentemente identificados. Como a obesidade é uma situação cardiometabólica muito complexa, essa identificação deve ser feita em obesos não-complicados e em modelos animais adequados. A recente descoberta da transmissão inter-geração de fatores de risco da obesidade e também do papel fundamental da gestação e de eventos perinatais (fatores epi-genéticos) dão origem a conceitos e linhas de pesquisa completamente novos. Considerando a estreita relação potencial entre a microcirculação e o metabolismo tecidual, demonstrações de anormalidades estruturais e/ou funcionais na fisiologia microvascular muito cedo na vida de pessoas com risco para obesidade podem fornecer uma base sólida para investigações futuras dessas ligações. A microcirculação (arteríolas, capilares e vênulas) é conceitualmente um compartimento chave na determinação em uma ou várias décadas dos fatores genéticos e epi-genéticos em acúmulo de gordura. Os modelos experimentais disponíveis devem servir para responder essa questão extremamente relevante.

Adiposidad visceral y su asociación con lípidos séricos e insulinemis en adolescentes obesas / Visceral adiposity and its association with serum lipids in female obese teenagers

Background: Increased visceral or abdominal adipose tissue in children and adults is strongly associated with metabolic and a variety of chronic diseases. Aim: To study the association between visceral or external body measurements of adiposity with blood lipids, glucose and insulin levels, in obese female adolescents. Material and methods: In a cross-sectional study, 47 obese female adolescents (body mass index (BMI) >95th percentile) aged 10 to 15 years, were analyzed. Weight, height, BMI, Tanner pubertal stages, skinfold thickness, waist circumference, waist-to-hip ratio, fasting and 120 min post prandial blood glucose, serum insulin, and lipid profile were studied. Visceral fat was assessed by computed tomography at the L4-L5 level, measuring the fat area or the length of a straight drawn line between the spine and the internal border of the rectus abdominus muscle. Results: No association between lipid profile and BMI or external body measurements (skinfold thickness, waist circumference, waist-to-hip ratio) was observed. Total serum cholesterol >170 mg/dL was positively associated with the straight line over 63 mm (a cut-off obtained by ROC analysis (RR 2.64; 1.15-6.08). This association was statistically significant in girls in Tanner I + II (n =21; Fisher, p <0.023), but not with Tanner III + IV (n =26) stages. Increased cholesterol (>170 mg/dL) was also positively associated with a serum insulin >17 uU/mL in the Tanner I + II group (Fisher p<0.05), but not with the homeostasis model assessment of insulin resistance (HOMA). Conclusions: No external body measurement of adiposity was associated to increased serum cholesterol in these obese female adolescents. Increased total cholesterol (>170 mg/dL) was associated with visceral fat (evaluated through the straight line spina-rectus abdominus muscle), and also with a serum insulin >17 uU/ml in those teenagers with Tanner I or II pubertal stages.

Gordura visceral e síndrome metabólica: mais que uma simples associação / Visceral fat and metabolic syndrome: more than a simple association

A síndrome metabólica (SM) é vista atualmente como uma epidemia mundial, com números alarmantes, associada a alta morbi-mortalidade cardiovascular e elevado custo sócio-econômico. O ganho ponderal é preditor independente para o desenvolvimento da SM, embora nem todos os indivíduos obesos a apresentem. Por outro lado, certas populações com baixa prevalência de obesidade apresentam elevada prevalência da SM e mortalidade cardiovascular. A distribuição da gordura corporal é relevante, e especificamente a gordura visceral (GV) parece ser o elo entre o tecido adiposo e a resistência à insulina (RI), característica da SM. Na última década, o tecido adiposo deixou de ser um simples reservatório de energia para se transformar num complexo órgão com múltiplas funções. A GV apresenta características metabólicas diferentes da gordura subcutânea glúteo-femoral, as quais favorecem a instalação do quadro de RI. Diversos estudos revelam a estreita relação da adiposidade abdominal com a tolerância à glicose, hiperinsulinemia, hipertrigliceridemia e hipertensão arterial. Mais que uma simples associação, recentemente, acredita-se que a GV desempenha um papel central na fisiopatologia da SM. Assim, a quantificação da GV se torna importante para identificar indivíduos com maior risco para o desenvolvimento da SM, eleitos para sofrer intervenções precoces na tentativa de reduzir o impacto das anormalidades metabólicas sobre a mortalidade cardiovascular. Este artigo discute particularidades da distribuição central de gordura, no contexto da SM, possíveis mecanismos fisiopatogênicos relacionados à GV e os métodos disponíveis para a avaliação da adiposidade abdominal.

Metabolic syndrome (MS) is seen nowadays as a worldwide epidemic event associated with high cardiovascular morbi-mortality and high socioeconomic cost. The ponderal gain is an independent predictor for the development of MS, although not all obese individuals present it. On the other hand, some populations with low obesity prevalence present high prevalence of MS and cardiovascular mortality. The distribution of corporal fat is relevant and visceral fat (VF), specifically, seems to be the link between adipose tissue and insulin resistance (IR), a mean feature of MS. Adipose tissue is now considered a complex organ with multiple functions. VF presents metabolic properties, which are different from the gluteo-femoral subcutaneous fat and related to IR. Several studies show the narrow relationship of abdominal adiposity with the glucose tolerance, hyperinsulinemia, hypertriglyceridemia and arterial hypertension. More than a simple association, recently it is thought that the VF plays a central part in the physiopathology of MS. Consequently, the quantification of VF plays an important role to identify individuals with larger risk for development of MS, who should be chosen for early interventions in the attempt of reducing the impact of metabolic abnormalities on cardiovascular mortality. This article discusses particularities of the central distribution of fat in MS context, possible physiopathogenic mechanisms related to the VF and available methods for the evaluation of abdominal adiposity.