RESUMO

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.

RESUMO

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 (Á). 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 Á. 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.

Assuntos

RESUMO

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 (Á). 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 Á > 1, known as "Heywood case", and the existence of negative correlations, which do not allow the calculation of Á. 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.

O 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.

Assuntos