Valéria Troncoso Baltar

Breast cancer and dietary patterns: a systematic review

This systematic review collates research on the topic of dietary patterns and breast cancer risks. The literature search targeted epidemiological studies published up to December 2012 and was conducted using the Medline (U.S. National Library of Medicine, Bethesda MD, USA) and Lilacs (Latin American and Caribbean Health Sciences, São Paulo, Brazil) databases. The following search terms were used: breast cancer, breast neoplasm, breast carcinoma, diet, food, eating habits, dietary patterns, factor analysis, and principal component analysis. Only studies that used factor analysis techniques and/or principal component analysis were eligible, and a total of 26 studies were included. The findings of these studies suggest the Mediterranean dietary pattern and diets composed largely of vegetables, fruit, fish, and soy are associated with a decreased risk of breast cancer. There was no evidence of an association between traditional dietary patterns and risk of breast cancer, and only one study showed a significant increase in risk associated with the Western dietary pattern. Diets that include alcoholic beverages may be associated with increased risk.

Dietary patterns for meals of Brazilian adults.

The use of dietary patterns (DP) in nutritional research is well established; however, only a few studies of DP according to specific meals have been conducted. The purpose of this study was to identify the DP regarding breakfast, lunch and dinner meals of the population (aged 20 years and older of both sexes) that participated in the Health Care Survey of Sao Paulo. Food intake was estimated by using the Multiple Source Method - considering two 24- h dietary recalls. On the basis of the food groups for each meal, a factor analysis, with a principal component estimation, was applied (varimax rotation) in order to derive the DP. Prevalences of meal skipping were 5·6 % for breakfast, 3·6 % for lunch and 12·8 % for dinner. The findings revealed three breakfast DP: healthy, traditional and snack; five lunch DP: traditional, salad, sweetened juice, Western and meats; and four dinner DP: coffee with milk and bread, transitional, traditional, and soup and fruits. The results of this study indicate that the DP identified in accordance with the meal nicely discriminates food intake, emphasising peculiarities that are not found in global analyses and might support dietary advice.

Attitudes of nursing staff related to the nursing process

The aims of the study were to describe nurses’ positions on nursing process and their perception of power; and to analyse asso ciations between positions on nursing process, power perception and selected variables. One thousand six hundred and five nurses (86.9% female, mean age=44.12 years, SD=9.55) participated in the study. Mean score on the Positions on Nursing Process (PNP) tool was 112.37 (SD=22.28); and on the Power as Knowing Participation in Change Tool – Brazilian Version (PKPCT) was 281.12 (SD=38.72). Baccalaureate nurses had statistically higher scores on PNP and PKPCT than auxiliary nurses. There was positive and moderate correlation between PNP and PKPCT scores. Auxiliary nurses’ scores on PNP were associated with sex and post-graduation; auxiliary nurses’ scores on PKPCT were associated with sex. For baccalaureate nurses there was association between PKPCT and admi nistrative position. More studies should be developed in order to identify variables po tentially associated with the use of nursing process in clinical practice.

Atitudes dos profissionais de enfermagem relacionadas ao Processo de Enfermagem

The aims of the study were to describe nurses’ positions on nursing process and their perception of power; and to analyse asso ciations between positions on nursing process, power perception and selected variables. One thousand six hundred and five nurses (86.9% female, mean age=44.12 years, SD=9.55) participated in the study. Mean score on the Positions on Nursing Process (PNP) tool was 112.37 (SD=22.28); and on the Power as Knowing Participation in Change Tool – Brazilian Version (PKPCT) was 281.12 (SD=38.72). Baccalaureate nurses had statistically higher scores on PNP and PKPCT than auxiliary nurses. There was positive and moderate correlation between PNP and PKPCT scores. Auxiliary nurses’ scores on PNP were associated with sex and post-graduation; auxiliary nurses’ scores on PKPCT were associated with sex. For baccalaureate nurses there was association between PKPCT and admi nistrative position. More studies should be developed in order to identify variables po tentially associated with the use of nursing process in clinical practice.

Sex differences in serum leptin and its relation to markers of cardiometabolic risk in middle-aged adults: Evidence from a population-based study

OBJECTIVE At elevated concentrations, circulating leptin has been associated with metabolic disturbances, namely insulin resistance, elevated blood pressure, inflammation, and endothelial dysfunction. Because women have higher leptin concentrations than men, it is possible that the effects of leptin on the metabolic profile are different between the sexes. The aim of this study was to investigate whether leptin is one of the key hormones to sex affect differences in the pathophysiology of cardiometabolic risk. METHODS Participants were 178 men and 284 women (average age: 53.9 y), evaluated in a cross-sectional, population-based study performed in Brazil. A structural equation model was used to test a theoretic pathway for the relationship between serum leptin, obesity indicators (body weight and waist circumference), and cardiometabolic risk factors (high-sensitivity C-reactive protein; blood pressure; atherogenic dyslipidemia-total cholesterol/high-density lipoprotein cholesterol (HDL-C) ratio and triacylglycerol /HDL-C ratio; and fasting plasma glucose) stratified by sex. RESULTS In men, increasing 1 SD in serum leptin predicted an increase in 0.731 SD in body weight and in 0.123 SD in C-reactive protein. Serum leptin had positive and significant indirect effects on mens ratios of total cholesterol to HDL-C (β = 0.215) and triacylglycerol to HDL-C (β = 0.209), as well as fasting glucose (β = 0.173). In women, serum leptin predicted an increase of 0.675 SD in body weight and had positive indirect effects on all cardiometabolic risk factors evaluated. CONCLUSIONS Serum leptin was indirectly related to cardiometabolic risk factors and its relation was modest and different between sexes. The effects of leptin through mediation of body weight and waist circumference highlight the importance of weight control to prevent cardiometabolic disorders in middle-aged adults.

Empirically derived dietary patterns: interpretability and construct validity according to different factor rotation methods

This study aimed to investigate the effects of factor rotation methods on interpretability and construct validity of dietary patterns derived in a representative sample of 1,102 Brazilian adults. Dietary patterns were derived from exploratory factor analysis. Orthogonal (varimax) and oblique rotations (promax, direct oblimin) were applied. Confirmatory factor analysis assessed construct validity of the dietary patterns derived according to two factor loading cut-offs (≥ |0.20| and ≥ |0.25|). Goodness-of-fit indexes assessed the model fit. Differences in composition and in interpretability of the first pattern were observed between varimax and promax/oblimin at cut-off ≥ |0.20|. At cut-off ≥ |0.25|, these differences were no longer observed. None of the patterns derived at cut-off ≥ |0.20| showed acceptable model fit. At cut-off ≥ |0.25|, the promax rotation produced the best model fit. The effects of factor rotation on dietary patterns differed according to the factor loading cut-off used in exploratory factor analysis.Objetivou-se investigar os efeitos dos metodos de rotacao fatorial na interpretabilidade e validade de construto de padroes alimentares em uma amostra representativa de 1.102 adultos brasileiros. Os padroes foram derivados por analise fatorial exploratoria. As rotacoes ortogonal (varimax) e obliqua (promax e oblimin direta) foram utilizadas. Avaliou-se a validade de construto dos padroes segundo os pontos de corte de cargas fatoriais: (≥ |0,20| e ≥ |0,25|) por meio de analise fatorial confirmatoria. Indices de qualidade de ajuste do modelo foram analisados. Observaram-se diferencas na composicao e interpretabilidade do primeiro padrao obtido pelas rotacoes varimax e promax/oblimin no ponto de corte ≥ |0,20|. No ponto de corte ≥ |0,25|, nao foram observadas diferencas. Nenhum dos padroes derivados no ponto de corte ≥ |0,20| apresentou qualidade de ajuste aceitavel. No ponto de corte ≥ |0,25|, a rotacao promax obteve o melhor ajuste. Os efeitos das rotacoes nos padroes alimentares diferiram segundo o ponto de corte de carga fatorial utilizado na analise fato-rial exploratoria.

Adaptation and validation of the instrument positions on the nursing process

OBJETIVO: estimar las propiedades psicometricas de la adaptacion del instrumento Posicoes frente o diagnostico de enfermagem para evaluar las actitudes del personal de enfermeria respecto al proceso de enfermeria. METODO: estudio metodologico con muestra no probabilistica de 973 auxiliares de enfermeria y 632 enfermeros de 35 hospitales y ambulatorios vinculados a la Secretaria del Estado de la Salud de Sao Paulo. La validez del instrumento de 20 items fue verificada mediante el analisis factorial confirmatorio que identifico un factor mas general en segundo nivel, formado por los tres factores clasicos de actitudes. La confiabilidad correspondio a 0,954 para el instrumento total. RESULTADOS: el instrumento Posicoes sobre o Processo de Enfermagem posee validez y confiabilidad adecuadas. CONCLUSIONES: se recomienda verificar en estudios futuros si los items presentan comportamiento diferencial segun la categoria profesional del respondiente y verificar el comportamiento del instrumento con estudiantes

A mixed-effect model for positive responses augmented by zeros

In this research article, we propose a class of models for positive and zero responses by means of a zero-augmented mixed regression model. Under this class, we are particularly interested in studying positive responses whose distribution accommodates skewness. At the same time, responses can be zero, and therefore, we justify the use of a zero-augmented mixture model. We model the mean of the positive response in a logarithmic scale and the mixture probability in a logit scale, both as a function of fixed and random effects. Moreover, the random effects link the two random components through their joint distribution and incorporate within-subject correlation because of the repeated measurements and between-subject heterogeneity. A Markov chain Monte Carlo algorithm is tailored to obtain Bayesian posterior distributions of the unknown quantities of interest, and Bayesian case-deletion influence diagnostics based on the q-divergence measure is performed. We apply the proposed method to a dataset from a 24 hour dietary recall study conducted in the city of São Paulo and present a simulation study to evaluate the performance of the proposed methods.

Design of a school randomized trial for nudging students towards healthy diet and physical activity to prevent obesity: PAAPAS Nudge study protocol

Objective: To evaluate the effectiveness of nudge activities at school on the students’ body mass index (BMI). Design: School-based factorial randomized community trial. Setting: Eighteen public schools in the municipality of Duque de Caxias, metropolitan area of Rio de Janeiro, Brazil. Participants and intervention: The 18 schools will be randomized into 4 group arms: group 1—control (without any activity); group 2—will receive educational activities in the classroom; group 3—will receive changes in the school environment (nudge strategies); group 4—will receive educational activities and changes in the school environment. Activities will occur during the 2018 school-year. Main outcome measure(s): The primary (BMI) and secondary (body fat percentage) outcomes will be assessed at baseline and after the study using a portable electronic scale with a segmental body composition monitor. The height will be measured by a portable stadiometer. Analysis: Statistical analyses for each outcome will be conducted through linear mixed models that took into account the missing data and cluster effect of the schools.

Padrões alimentares empiricamente derivados: interpretabilidade e validade de construto segundo diferentes métodos de rotação fatorial

This study aimed to investigate the effects of factor rotation methods on interpretability and construct validity of dietary patterns derived in a representative sample of 1,102 Brazilian adults. Dietary patterns were derived from exploratory factor analysis. Orthogonal (varimax) and oblique rotations (promax, direct oblimin) were applied. Confirmatory factor analysis assessed construct validity of the dietary patterns derived according to two factor loading cut-offs (≥ |0.20| and ≥ |0.25|). Goodness-of-fit indexes assessed the model fit. Differences in composition and in interpretability of the first pattern were observed between varimax and promax/oblimin at cut-off ≥ |0.20|. At cut-off ≥ |0.25|, these differences were no longer observed. None of the patterns derived at cut-off ≥ |0.20| showed acceptable model fit. At cut-off ≥ |0.25|, the promax rotation produced the best model fit. The effects of factor rotation on dietary patterns differed according to the factor loading cut-off used in exploratory factor analysis.Objetivou-se investigar os efeitos dos metodos de rotacao fatorial na interpretabilidade e validade de construto de padroes alimentares em uma amostra representativa de 1.102 adultos brasileiros. Os padroes foram derivados por analise fatorial exploratoria. As rotacoes ortogonal (varimax) e obliqua (promax e oblimin direta) foram utilizadas. Avaliou-se a validade de construto dos padroes segundo os pontos de corte de cargas fatoriais: (≥ |0,20| e ≥ |0,25|) por meio de analise fatorial confirmatoria. Indices de qualidade de ajuste do modelo foram analisados. Observaram-se diferencas na composicao e interpretabilidade do primeiro padrao obtido pelas rotacoes varimax e promax/oblimin no ponto de corte ≥ |0,20|. No ponto de corte ≥ |0,25|, nao foram observadas diferencas. Nenhum dos padroes derivados no ponto de corte ≥ |0,20| apresentou qualidade de ajuste aceitavel. No ponto de corte ≥ |0,25|, a rotacao promax obteve o melhor ajuste. Os efeitos das rotacoes nos padroes alimentares diferiram segundo o ponto de corte de carga fatorial utilizado na analise fato-rial exploratoria.