Effect of vitamin K in bone metabolism and vascular calcification: A review of mechanisms of action and evidences.

Osteoporosis is a public health concern associated with an increased risk of bone fractures and vascular calcification. Vitamin K presents unique benefits on these issues, although understudied. The two main forms of vitamin K are phylloquinone (vitamin K1) and menaquinone (vitamin K2). In this study, it was especially investigated the action of vitamin K2 in bones and vessels. Vitamin K2 has shown to stimulate bone formation by promoting osteoblast differentiation and carboxylation of osteocalcin, and increasing alkaline phosphatase, insulin-like growth factor-1, growth differentiation factor-15, and stanniocalcin 2 levels. Furthermore, vitamin K2 reduces the pro-apoptotic proteins Fas and Bax in osteoblasts, and decreases osteoclast differentiation by increasing osteoprotegerin and reducing the receptor activator of nuclear factor kappa-B ligand. In blood vessels, vitamin K2 reduces the formation of hydroxyapatite, through the carboxylation of matrix Gla protein and Gla rich protein, inhibits the apoptosis of vascular smooth muscle cells, by increasing growth arrest-specific gene 6, and reduces the transdifferentiation of vascular smooth muscle cells to osteoblasts. The commonly used dosage of vitamin K2 in human studies is 45 mg/day and its application can be an interesting strategy in benefitting bone and vascular health, especially to osteoporotic post-menopausal women.

Padrões alimentares de crianças e determinantes socioeconômicos, comportamentais e maternos / Dietary patterns of children and socioeconomical, behavioral and maternal determinants

Objetivo:Identificar os padrões alimentares de crianças e verificar sua associação com determinantes socioeconômicos, comportamentais e maternos.Métodos:Estudo transversal com amostra aleatória de 328 crianças de oito e nove anos. O consumo alimentar foi avaliado por registros alimentares de três dias não consecutivos e quantificado em gramas de grupos alimentares e de nutrientes. Análise fatorial e subsequente rotação ortogonal (varimax) foram usadas para determinar os padrões alimentares. Regressão logística ordinal foi usada para verificar associações entre padrões alimentares e os determinantes estudados.Resultados:Cinco padrões alimentares foram extraídos: “Tradicional”, “Bebidas adoçadas e lanches”, “Monótono”, “Saudável” e “Ovo-lacto”. A maior escolaridade materna se associou de forma direta aos padrões “Bebidas doces e lanches” e “Ovo-lacto”. Crianças de baixo nível econômico e que recebiam maior restrição alimentar pelos pais/responsáveis aderiram mais ao padrão “Tradicional”, representado pelo consumo de arroz, feijão, hortaliças, raízes e tubérculos cozidos e carne vermelha. O padrão “Monótono”, representado pelo elevado consumo de leite e achocolatado, foi mais consumido por crianças de classe econômica intermediária. Crianças que residiam em zona rural consumiam mais alimentos do padrão “Ovo-lacto” comparadas com as de zona urbana.Conclusões:Os padrões alimentares das crianças estiveram associados às condições econômicas da família, escolaridade materna, prática de restrição alimentar pelos pais/responsáveis e localização da residência em zona urbana ou rural. Melhores condições socioeconômicas contribuíram para um padrão alimentar nutricionalmente mais inadequado.

Objective:To identify dietary patterns of children and to verify their association with socio-economical, behavioral and maternal determinants.Methods:A cross-sectional study with a random sample of 328 children aged 8 and 9 years. Dietary intake was assessed by food records in three nonconsecutive days and measured in grams of food groups and nutrients. Factor analysis and subsequent orthogonal rotation (varimax) were used to determine dietary patterns. Ordinal logistic regression was used to assess associations between dietary patterns and the studied determinants.Results:Five dietary patterns were observed: “Traditional,” “Sweetened beverages and snacks,” “Monotonous,” “Healthy” and “Egg-dairy.” A higher maternal level of education was directly associated with “Sweetened beverages and snacks” and “Egg-dairy' standards. Low income children who were submitted to greater food restriction by parents/guardians followed the more “Traditional” standard, represented by the consumption of rice, beans, vegetables, cooked roots and tubers and red meat. The “Monotonous” pattern, represented by a high consumption of milk and chocolate powder, was most followed by children from the middle class. Children living in rural areas consumed more foods from the “Egg-dairy” pattern, when compared to those from the urban area.Conclusions:Dietary patterns of children were associated with family socioeconomic status, maternal level of education, practice of food restriction by parents/guardians and location of residence in urban or rural area. Better socioeconomic conditions contributed to a more nutritionally inadequate dietary pattern.

[Dietary patterns of children and socioeconomical, behavioral and maternal determinants]. / Padrões alimentares de crianças e determinantes socioeconômicos, comportamentais e maternos.

OBJECTIVE: To identify dietary patterns of children and to verify their association with socio-economical, behavioral and maternal determinants. METHODS: A cross-sectional study with a random sample of 328 children aged 8 and 9 years. Dietary intake was assessed by food records in three nonconsecutive days and measured in grams of food groups and nutrients. Factor analysis and subsequent orthogonal rotation (varimax) were used to determine dietary patterns. Ordinal logistic regression was used to assess associations between dietary patterns and the studied determinants. RESULTS: Five dietary patterns were observed: "Traditional", "Sweetened beverages and snacks", "Monotonous", "Healthy" and "Ovo-lacto". A higher maternal level of education was directly associated with "Sweetened beverages and snacks" and "Ovo-lacto" standards. Low income children who were submitted to greater food restriction by parents/guardians followed the more "Traditional" standard, represented by the consumption of rice, beans, vegetables, cooked roots and tubers, and red meat. The "Monotonous" pattern, represented by a high consumption of milk and chocolate milk, was most followed by children from the middle class. Children living in rural areas consumed more foods from the "Ovo-lacto" pattern, when compared to those from the urban area. CONCLUSIONS: Dietary patterns of children were associated with family socioeconomic status, maternal level of education, practice of food restriction by parents/guardians and location of residence in urban or rural area. Better socioeconomic conditions contributed to a more nutritionally inadequate dietary pattern.

Metabolic syndrome risk assessment in children: use of a single score / Risco de síndrome metabólica em crianças: uso de um escore único

OBJECTIVE: To calculate a score of metabolic syndrome (MetS) in children and set a cutoff point of this score for the prediction of MetS risk. METHODS: The study included a random sample of 348 children aged 8 and 9 years of Viçosa, Southeast Brazil. Factor analysis by principal components (PCA) was used to determine, among various risk factors, those with higher degrees of intercorrelation. The chosen variables were: waist circumference (PC), homeostatic model assessment of insulin resistance (HOMA), high density lipoprotein (HDL), triglycerides (TAG) and mean arterial pressure (MAP). Z-scores were created for each one of these parameters and the sum of these z-scores constituted the MetS score. The receiver operating characteristic (ROC) curve was used to identify the cutoff of MetS score, using as gold standard the presence or absence of MetS determined according to criteria age-modified. RESULTS: The prevalence of MetS in the sample was 8.9% by adopting specific criteria for age, and 24% when considering the cutoff of MetS score. The selected cutoff point of 1.86 was accurate to predict the MetS risk in this sample due to its high sensitivity (96.7%), specificity (82.7%) and AUC of 0.96. CONCLUSIONS: This original Brazilian study presents the MetS score as a suitable alternative for the study of Metabolic Syndrome in children, given the lack of consensus for the definition of this syndrome in childhood.

OBJETIVO: Calcular um escore de síndrome metabólica (SM) em crianças e definir um ponto de corte para a predição de risco de SM nesse grupo. MÉTODOS: Estudo com amostra aleatória de 348 crianças de oito e nove anos do município de Viçosa. Análise fatorial por componentes principais foi usada para verificar, entre vários fatores de risco, aqueles com maiores graus de intercorrelação: perímetro da cintura (PC), modelo homeostático de resistência à insulina (HOMA), lipoproteína de alta densidade (HDL), triacilgliceróis (TAG) e pressão arterial média (PAM). Escores-z foram criados para cada um desses parâmetros e o somatório desses constituiu o escore de SM. A curva receiver operating characteristic (ROC) foi usada para identificar o ponto de corte do escore, considerando-se como padrão-ouro a presença ou ausência de SM, segundo critérios modificados para a idade. RESULTADOS: A prevalência de SM na amostra foi de 8,9% adotando-se critérios específicos para a idade e de 24% quando considerado o ponto de corte do escore. Foi eleito o ponto de corte de 1,86, por ter elevadas sensibilidade (96,7%) e especificidade (82,7%), AUC de 0,96, e, assim, acurácia em predizer a presença de síndrome metabólica em crianças nessa faixa etária. CONCLUSÕES: Este inédito estudo brasileiro apresenta uma opção adequada para o estudo da SM em crianças, vista a ausência de definição consensual para a SM na infância.

[Metabolic syndrome risk assessment in children: use of a single score]. / Risco de síndrome metabólica em crianças: uso de um escore único.

OBJECTIVE: To calculate a score of metabolic syndrome (MetS) in children and set a cutoff point of this score for the prediction of MetS risk. METHODS: The study included a random sample of 348 children aged 8 and 9 years of Viçosa, Southeast Brazil. Factor analysis by principal components (PCA) was used to determine, among various risk factors, those with higher degrees of intercorrelation. The chosen variables were: waist circumference (PC), homeostatic model assessment of insulin resistance (HOMA), high density lipoprotein (HDL), triglycerides (TAG) and mean arterial pressure (MAP). Z-scores were created for each one of these parameters and the sum of these z-scores constituted the MetS score. The receiver operating characteristic (ROC) curve was used to identify the cutoff of MetS score, using as gold standard the presence or absence of MetS determined according to criteria age-modified. RESULTS: The prevalence of MetS in the sample was 8.9% by adopting specific criteria for age, and 24% when considering the cutoff of MetS score. The selected cutoff point of 1.86 was accurate to predict the MetS risk in this sample due to its high sensitivity (96.7%), specificity (82.7%) and AUC of 0.96. CONCLUSIONS: This original Brazilian study presents the MetS score as a suitable alternative for the study of Metabolic Syndrome in children, given the lack of consensus for the definition of this syndrome in childhood.