Método das tríades na validação do consumo alimentar com biomarcadores

The triads method is applied in validation studies of dietary intake to evaluate the correlation between three measurements (food frequency questionnaire, reference method and biomarker) and the true intake using validity coefficients (ρ). The main advantage of this technique is the inclusion of the biomarker, which presents independent errors compared with those of the traditional methods. The method assumes the linearity between the three measurements and the true intake and independence between the three measurement errors. Limitations of this technique include the occurrence of ρ > 1, known as “Heywood case”, and the existence of negative correlations, which do not allow the calculation of ρ. The objective of this review is to present the concept of the method, describe its application and examine the validation studies of dietary intake that use the triads method. We also conceptualize the “bootstrap” method, used to estimate the confidence intervals of the validity coefficients. ______________________________________________________________________________________________________________ RESUMOO método das tríades vem sendo utilizado em estudos de validação do consumo alimentar para avaliação da correlação entre três variáveis (questionário de freqüência alimentar, método de referência e biomarcador) e a ingestão real, por meio dos coeficientes de validade (Á). A principal vantagem deste método é a inclusão do biomarcador, que apresenta erros independentes dos métodos tradicionais. Os pressupostos desta técnica são a linearidade entre as três variáveis e a ingestão real, e a existência de erros independentes entre as variáveis. Entre as limitações deste método, destaca-se a existência de Á > 1, conhecido como "Heywood case", e de correlações negativas, que não permitem o cálculo do Á. O objetivo deste trabalho foi apresentar o conceito do método, descrever a sua aplicação e examinar estudos de validação do consumo alimentar que utilizaram o método das tríades, além de conceituar o método "bootstrap" para obtenção de intervalos de confiança dos coeficientes de validade

Adherence to a nutritional counseling program for adults with excess weight and comorbidities

Objetivo: Investigar adesão a programa de aconselhamento nutricional em grupo para indivíduos com excesso de peso e comorbidades. Métodos: Estudo analítico de intervenção controlada e aberta. Oitenta adultos, de ambos os sexos, com índice de massa corporal entre 25 e 35kg/m², portadores de dois ou mais fatores de risco cardiovascular associados foram alocados aleatoriamente em dois grupos para acompanhamento por três meses. O grupo de intervenção com aconselhamento nutricional em grupo recebeu atendimento individual e participou de seis reuniões grupais para discussão sobre alimentação saudável e atividade física, com dinâmicas e método participativo. O grupo-controle, com atendimento padrão individual, foi assistido em três consultas ambulatoriais. Consideraram-se repercussões dietéticas antes e após a intervenção e assiduidade às reuniões como parâmetros de adesão ao tratamento. Resultados: Trinta e três participantes concluíram o estudo. Do total inicial, 45,8% e 40,7% do grupo de intervenção com aconselhamento nutricional em grupo e do grupo-controle com atendimento padrão individual, respectivamente, atingiram nível ótimo de assiduidade. Os fatores mais citados como barreiras à adesão ao tratamento foram fazer refeições fora de casa (46,7% - grupo-controle com atendimento padrão individual) e dificuldade em aplicar os conhecimentos na prática, principalmente em eventos sociais (33,3% - grupo de intervenção com aconselhamento nutricional em grupo). Verificou-se aumento significativo do percentual médio do uso de temperos naturais e do número de refeições ao dia nos dois grupos após a intervenção. Porém, não houve diminuição significativa do consumo energético intra ou entre os grupos. Conclusão: Apesar da abrangência do conteúdo e do emprego de um método participativo no grupo de intervenção, a adesão foi insuficiente para alterar significativamente os principais parâmetros dietéticos estudados. O aprofundamento da abordagem comportamental, continuada e ultiprofissional deve ser objeto de mais investigações. _______________________________________________________________________________________________________________ ABSTRACTObjective: The objective of this study was to verify adherence to a nutritional group counseling program for patients with excess weight and comorbidities. Methods: This was an analytical, open, controlled, intervention study. Eighty adults from both genders with a body mass index ranging from 25 to 35kg/m² with two or more associated cardiovascular risk factors were randomly allocated to two groups for a three-month follow-up. The intervention group with nutritional group counseling received personalized care and participated in six group meetings to discuss healthy eating and physical activity, with group dynamics and participatory method. The control group was given standard personalized care in three outpatient visits. The parameters of adherence to treatment were the dietary repercussions before and after the intervention and attendance to the meetings. Results: Thirty-three participants concluded the study. In all, 45.8% and 40.7% of intervention group and control group, respectively, had excellent attendance. The main barriers to adherence to treatment were the need of eating out (46.7% - control group) and the difficulty of putting their knowledge to use, especially in social occasions (33.3% - intervention group). There was a significant increase in the mean percentage use of natural seasonings and in the number of daily meals of both groups after the intervention. However, there was no significant decrease in energy intake within groups or between groups. Conclusion: Despite the breadth of the content and the use of a participatory method in the intervention group, adherence was not enough to change the main dietary parameters significantly

Metabolic syndrome in central Brazil : prevalence and correlates in the adult population

Background: The prevalence of metabolic syndrome (MetS) has increased in developing countries in recent decades. This syndrome, a clustering of metabolic abnormalities, has been correlated to various socioeconomic and behavioral variables. We investigated the prevalence and prevalence ratios (PR) of MetS and related factors in an adult population of the Federal District (FD) of Brazil, which is located in the central region of the country. Methods: A cross-sectional, population-based study conducted in 2007, with 2130 adults (aged 18 years or older) in the FD of Brazil. Metabolic syndrome was defined according to the recently harmonized criteria. The prevalence of MetS and PR were estimated for each sex according to the diagnostic components and the overall contribution of the selected correlates. Results: The overall prevalence of MetS was 32.0% (95%CI: 28.9–35.2), with no gender difference. The single component with the greatest contribution to the diagnosis of MetS was hypertension in men (PR 5.10, 95%CI: 3.17–8.22) and high waist circumference in women (PR 5.02, 95%CI: 3.77–6.69). The prevalence of MetS increased significantly and progressively with age and excess weight. In women, higher education was protective against MetS (PR 0.66, 95%CI: 0.49–0.89) compared to 8 or less years of education. There was no association between the prevalence of MetS and behavioral variables studied. Conclusions: This study provides comprehensive and alarming data about the prevalence of MetS among the adult population of Brazil’s FD. The results suggest that reducing education inequalities may be an important public policy goal to improve health outcomes, especially among women

Fatty acid composition of hydrogenated or interesterified margarines

Foi analisado o conteúdo de ácidos graxos (AG) de 12 marcas de margarinas à base de óleos vegetais parcialmente hidrogenados ou interesterificados comercializados no Distrito Federal. As margarinas foram agrupadas pelo tipo de óleos utilizados em sua produção e o percentual médio de lipídios em GH-T (margarinas hidrogenadas com 50% de lipídios), GH-L (hidrogenadas com 20%), GI-T (interesterificadas com 65%) e GI-L (interesterificadas com 30%). O perfil de AG foi obtido por cromatografia gasosa em coluna capilar SP2560®. O conteúdo de AG trans (AGT) no GH-T (7,91 ± 1,05 g.100 g–1) foi significativamente maior (p < 0,05) que no GH-L (2,46 ± 0,39  g.100 g–1), GI-T (1,29  ± 0,47 g.100 g–1) e GI-L (0,65 ± 0,24 g.100 g–1). Houve diferença significativa no conteúdo total de AG saturados (AGS) e insaturados (AGI) entre os grupos GH-T e GI-T, sendo maior no GI-T, seguido de GH-T e sem diferença significativa entre GH-L e GI-L. Porém, as razões entre ΣAGP/ΣAGS das margarinas não variou entre os grupos, enquanto as razões entre ΣAGP/ΣAGT nas margarinas GI-T e GI-L foram superiores às demais. Os resultados obtidos indicam que as margarinas GI-T e GI-L seriam mais apropriadas para consumo humano, por possuírem menos AGT e uma melhor razão AGP/AGT que as demais. ______________________________________________________________________________________________________________ ABSTRACTThe content of fatty acids (FA) of 12 margarine brands produced with partially hydrogenated or interesterified vegetable oils marketed in Federal District was analyzed. The margarines were grouped into four groups by the type of oils used in their production and by the average percentage of lipids: GH-T (hydrogenated margarines with 50% lipids), GH-L (hydrogenated with 20%), GI-T (interesterified with 65%) and GI-L (interesterified with 30%). The fatty acid profile was obtained by gas chromatography in a SP2560® capillary column. The content of trans fatty acids (TFA) in GH-T (7.91 ± 1.05 g.100 g–1) was significantly higher (p < 0.05) than in GH-L (2.46  ±   0.39  g.100 g–1), GI-T (1.29  ± 0.47  g.100 g–1) and GI-L (0.65 ± 0.24 g.100 g–1). There was a significant difference in the total content of saturated fatty acids (SFA) and in the unsaturated fatty acids (UFA) among the groups GH-T and GI-T, being higher in GI-T, followed by GH-T and with no significant difference between GH-L and GI-L. The ΣPUFA/ΣSFA ratios of the margarines were unchanged among the groups, while the ΣPUFA/ΣTFA ratios in the GI-T and GI-L groups were higher than in the others. The results suggest that GI-L and GI-T margarines would be more appropriate for human intake due to lower content of TFA and higher PUFA/TFA ratio than the others

Índices de avaliação da qualidade da dieta

Various indices and scores based on admittedly healthy dietary patterns or food guides for the general population, or aiming at the prevention of diet-related diseases have been developed to assess diet quality. The four indices preferred by most studies are: the Diet Quality Index; the Healthy Eating Index; the Mediterranean Diet Score; and the Overall Nutritional Quality Index. Other instruments based on these indices have been developed and the words 'adapted', 'revised', or 'new version I, II or III' added to their names. Even validated indices usually find only modest associations between diet and risk of disease or death, raising questions about their limitations and the complexity associated with measuring the causal relationship between diet and health parameters. The objective of this review is to describe the main instruments used for assessing diet quality, and the applications and limitations related to their use and interpretation.Para avaliação da qualidade da dieta, diferentes índices ou escores foram desenvolvidos, considerando padrões dietéticos reconhecidamente saudáveis ou baseando-se em guias alimentares para populações em geral ou para a prevenção de doenças. Dos vários índices, quatro deles servem de base para a maior parte dos estudos: Índice de Qualidade da Dieta, Índice de Alimentação Saudável, Escore da Dieta Mediterrânea e Índice Geral de Qualidade Nutricional. A partir desses modelos, alguns outros foram criados, com acréscimo do termo adaptado/revisado, ou em novas versões (I, II ou III) como referência do respectivo original. Esses índices, mesmo validados, apresentam associações geralmente modestas com o risco de mortalidade ou doenças, o que aponta suas limitações, bem como a complexidade de se medir a relação causal entre dieta e parâmetros de saúde. Esta revisão tem como objetivo descrever os principais instrumentos de avaliação da qualidade da dieta, assim como suas aplicações e limitações, relativas ao uso e interpretações

Validation of ultrasound examination for assessment of the abdominal visceral fat in clinically serious obese patient

RACIONAL: A tomografia computadorizada é o padrão-ouro para a medida da gordura abdominal visceral. No entanto é dispendiosa e envolve submeter os doentes à radiação ionizante. OBJETIVO: Validar o método ultrassonográfico para avaliação da gordura abdominal visceral em obesos clinicamente graves de ambos os sexos. MÉTODOS: A amostra incluiu adultos com obesidade clinicamente grave que apresentavam índice de massa corporal de 40kg/m² ou entre 35kg/m² e 40kg/m² com comorbidades associadas. Os exames realizados para medição da espessura da gordura visceral foram: ultrassonografia e de tomografia computadorizada. Foram realizados dois exames para avaliação da reprodutibilidade interobservador em uma subamostra de pacientes. O estudo ultrassonográfico foi validado comparando-o aos resultados do exame tomográfico. RESULTADOS: Participaram do estudo 13 pacientes, sendo 61,54% mulheres com IMC médio de 38,82kg/m². A validação foi feita pelo coeficiente de correlação de Pearson resultando ser igual a 0,94 (p = 0,0005). Evidenciou-se correlação positiva e forte entre as duas medidas. Quanto aos resultados da reprodutibilidade, o coeficiente de correlação intraclasse interobservador foi igual a 0,822 com intervalo de confiança de 95% (-0,076 a 0,980), o que revela boa concordância interobservador. A diferença média entre os dois observadores na ultrassonografia foi igual a 0,10 ± 1,51 (p = 0,8898), não significativa e sem viés significativo interobservador. CONCLUSÃO: Foi efetiva a validação do exame ultrassonográfico como substituição ao tomográfico para avaliar a gordura abdominal visceral entre obesos clinicamente graves. A medida ultrassonográfica independe do examinador.BACKGROUND: Computerized tomography is the gold-standard for measurement of abdominal visceral fat. However, it is costly and involves submitting patients to ionizing radiation. AIM: To validate the use of ultrasonography in assessing abdominal visceral fat among clinically serious obese patients of both genders. METHODS: The sample included adult patients with clinically serious obesity with body mass index of 40kg/m2 or from 35kg/m2 to 40kg/m2 with co-morbidities. Abdominal visceral fat thickness was measured using ultrasound and tomography. Two ultrasonographic exams were conducted to assess the interobserver reproducibility among a patient subsample. Validation was done by comparing these results with the tomographic findings. RESULTS: The study included 13 patients (61.54% female) with an average BMI of 38.82 kg/m2. In terms of validation, the result obtained from applying the Pearson correlation coefficient was equal to 0.94 (p = 0.0005), showing a strong positive correlation between the two measurements. As for the results for reproducibility, the interobserver was equal to 0.822, with a confidence interval of 95% (-0.076 to 0.980), revealing good interobserver agreement. The average difference between the two ultrasound interobserver examination was equal to 0.10 ± 1.51 (p=0.8898) and so not significant. Interobserver bias was also not significant. CONCLUSION: The validation of ultrasonographic examination to replace tomographic method in assessing abdominal visceral fat among clinically serious obese patients was effective. The ultrasound measurement is independent of the examiner

Omega-3 docosahexaenoic acid induces pyroptosis cell death in triple-negative breast cancer cells

The implication of inflammation in pathophysiology of several type of cancers has been under intense investigation. Omega-3 fatty acids can modulate inflammation and present anticancer effects, promoting cancer cell death. Pyroptosis is an inflammation related cell death and so far, the function of docosahexaenoic acid (DHA) in pyroptosis cell death has not been described. This study investigated the role of DHA in triggering pyroptosis activation in breast cancer cells. MDA-MB-231 breast cancer cells were supplemented with DHA and inflammation cell death was analyzed. DHA-treated breast cancer cells triggered increased caspase-1and gasdermin D activation, enhanced IL-1β secretion, translocated HMGB1 towards the cytoplasm, and membrane pore formation when compared to untreated cells, suggesting DHA induces pyroptosis programmed cell death in breast cancer cells. Moreover, caspase-1 inhibitor (YVAD) could protect breast cancer cells from DHA-induced pyroptotic cell death. In addition, membrane pore formation showed to be a lysosomal damage and ROS formation-depended event in breast cancer cells. DHA triggered pyroptosis cell death in MDA-MB-231by activating several pyroptosis markers in these cells. This is the first study that shows the effect of DHA triggering pyroptosis programmed cell death in breast cancer cells and it could improve the understanding of the omega-3 supplementation during breast cancer treatment

Omega 3-DHA and delta-tocotrienol modulate lipid droplet biogenesis and lipophagy in breast cancer cells : the impact in cancer aggressiveness

Omega 3-docosahexaenoic acid (DHA) and vitamin E Delta-tocotrienol (Delta-T3) are extensively studied as protective nutrients against cancer development. Little is known about the biological mechanisms targeted by these bioactive molecules on lipid droplet (LD) biogenesis, an important breast cancer aggressiveness marker, and the occurrence of lipophagy in breast cancer cells. The aim of this study was to investigate the effect of DHA, Delta-T3 and DHA plus Delta-T3 co-treatment in LD biogenesis and lipophagy process in triple negative breast cancer cell line MDA-MB-231. Cells were treated with 50 μM DHA and/or 5 μM Delta-T3. Our results demonstrated that DHA can trigger an increase in LD biogenesis and co-treatment with Delta-T3 was able to reduce this LD biogenesis. In addition, we showed that a higher cytoplasmic LD content is associated with a higher breast cancer cells malignance and proliferation. Reduction of cytoplasmic LD content by silencing ADRP (adipose differentiation-related protein), a structural LD protein, also decreased cell proliferation in MDA-MB-231 cells. Treatment with DHA and Delta-T3 alone or co-treatment did not reduce cell viability. Moreover, we showed here that DHA can trigger lipophagy in MDA-MB-231 cells and DHA plus Delta-T3 co-treatment was able to enhance this lipophagy process. Our findings demonstrated that co-treatment with DHA plus Delta-T3 in MDA-MB-231 cells could reduce LD biogenesis and potentiate lipophagy in these cells, possibly having a positive impact to inhibit breast cancer malignancy. Therefore, suitable doses of DHA and Delta-T3 vitamin E isoform supplementation can be a prominent tool in therapeutic treatments against breast cancer