This study evaluates the accuracy of cutoff points in the body mass index (BMI) for identifying adolescents with overweight, compared to the percentage of body fat, estimated by electric bioimpediance, in a probabilistic sample of 610 adolescents from 12 to 19 years of age (222 boys and 388 girls) enrolled in public schools in Niterói, Rio de Janeiro, Brazil. ROC was used to evaluate the sensitivity and specificity of BMI cutoffs from one Brazilian, two North American, and one international reference. The cutoff points in the study sample were lower than the other references, with 76% to 95% sensitivity and 75% to 95% specificity. The Brazilian cutoff points were also more sensitive (53% to 100%) as compared to the other references (40% to 86%). The international parameter showed better sensitivity for older adolescents, and the Northern American references for younger adolescents. BMI was a good proxy for adiposity, but cutoff points from other population references should be used with caution, since they can lead to classification errors in adolescents with overweight.

Avaliou-se a associação entre medidas antropométricas de localização de gordura central: circunferências da cintura (CC) e abdominal (CA) e as razões cintura/quadril (RCQ) e cintura/estatura (RCE), independente do percentual de gordura corporal (%GC) e índice de massa corporal (IMC), com os componentes da síndrome metabólica (SM) em uma amostra probabilística de 610 (222 meninos e 388 meninas) adolescentes de 12 a 19 anos de escolas públicas de Niterói, RJ. Foram avaliados glicose e perfil lipídico pelo método enzimático automatizado, insulina pela técnica de radioimunoensaio, %GC pela bioimpedância elétrica e a pressão arterial sistólica (PAS) e diastólica com manômetro digital. A associação entre as medidas antropométricas foi verificada por meio de regressão linear múltipla, com ajuste para IMC, %GC e idade. Nos meninos, a associação positiva entre CC (b = 1,03, p < 0,01) e RCE (b = 2,33, p < 0,05; b = 2,12 e p < 0,01) com triglicerídios foi mantida independente de IMC e % de GC, respectivamente. A CC se correlacionou com a PAS independente do %GC, tanto nos meninos (b = 0,70 p < 0,01) quanto nas meninas (b = 0,68 p < 0,01). Conclui-se que a CC foi a medida de gordura central que apresentou a melhor associação com os componentes da SM nos adolescentes.

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Objective: To compare the prevalence of metabolic abnormalities (MA) and metabolic syndrome (MS) assessed by different criteria among Brazilian adolescents. Subjects and methods: Weighted prevalence of MA and MS were estimated using criteria adapted from the International Diabetes Federation (IDF), National Cholesterol Education Program, Adult Treatment Panel III (NCEP/ATP III), and the World Health Organization (WHO) in a probabilistic sample of 577 students aged 12-19. Results: The most prevalent MA was low concentration of HDL-C as per IDF (32.5%) and NCEP/ATP III (41.6%) criteria and hypertension as per the WHO's criterion (12.4%). Prevalence of MS using the NCEP/ATP III criterion (6.04%) was five times higher than the WHO's (1.1%) and the IDF's (1.6%) criteria. As expected, MS was significantly higher among overweight than among non-overweight adolescents. Conclusion: Low prevalence of MS but high prevalence of some MA were found. These findings suggest that the diagnosis of MA is more relevant in clinical practice especially in overweight adolescents. WHO (12,4%). A prevalência de SM pelo critério NCEP/ATP III (6,04%) foi cinco vezes mais alta do que pelos critérios WHO (1,1%) e IDF (1,6%) e, como era esperado, foi significantemente mais elevada entre adolescentes com sobrepeso. Conclusão: Foram encontradas menores prevalências de SM e maiores prevalências de algumas AM. Esses resultados sugerem que o diagnóstico das AM é mais relevante na prática clínica especialmente para adolescentes com excesso de peso. Arq Bras Endocrinol Metab. 2011;55(2):164-70

Índice de massa corporal para predizer hiperglicemia e alterações lipídicas em adolescentes brasileiros ABSTRACT OBJECTIVE: To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS:A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (≥150mg/dL), LDL-C (≥ 100mg/dL), serum triglycerides (≥100mg/dL), plasma glucose (>100mg/dL) and low levels of HDL-C (< 45mg/dL). Four references were used to calculate sensitivity and specifi city of BMI cut-offs: one Brazilian, one international and two American. RESULTS:The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specifi city (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m² to 21.0 kg/m²) were lower than those proposed in the references studied. CONCLUSIONS:Although BMI values lower than the International cutoffs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.

Banana inflorescences are popularly known as 'navels,' and they are used in Brazil as nutritional complements. However, the nutritional value of banana inflorescences (male flowers and bracts) has never been studied. Therefore, plant material of Musa acuminata, cultivar "ouro", was collected in Rio de Janeiro state, Brazil, and then submitted to chemical procedures to determine its nutritional composition. The experiment was arranged a completely randomized design and performed in triplicate. The sample composition analysis showed percentual average value for moisture, protein, fat and ash as 8.21, 14.50, 4.04 and 14.43, respectively. The dehydrated inflorescences were found to contain a significant nutritive complement based on their high content of potassium (5008.26 mg / 100 g) and fiber 49.83% (lignin, cellulose and hemicelluloses) revealing important functional and nutritional properties. In a parallel evaluation, the anatomical study revealed key elements for the recognition of Musa acuminata when reduced to fragments.

Os estudos nacionais indicam comportamento epidêmico da obesidade, e ênfase tem sido dada sobre os determinantes sociais do excesso de peso. O status socioeconômico tem sido avaliado por ocupação, educação e renda. Vários fatores relacionados à obesidade, como atividade física, consumo alimentar e hábitos familiares sofrem também influência do status socioeconômico. Realizou-se revisão da literatura sobre a associação do status socioeconômico com obesidade e também foram apresentados dados de uma pesquisa de base populacional sobre obesidade em mulheres do município do Rio de Janeiro. A ocorrência da obesidade entre os diferentes níveis de status socioeconômico é influenciada pelo sexo e idade, e são discutidos fatores ambientais que determinam a possibilidade de acesso aos alimentos saudáveis e a oportunidade de prática de atividade física. Por fim, é discutido como os hábitos familiares influenciam nas escolhas dos alimentos e como o status socioeconômico pode modificar esse efeito, bem como a disponibilidade de alimentos e o preço destes, levando a um maior consumo de alimentos de alta densidade energética, fator de risco dietético para obesidade.

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