Vera Lucia Chiara

Sensibilidade e especificidade de classificação de sobrepeso em adolescentes, Rio de Janeiro

OBJECTIVE: To evaluate the prevalence, sensitivity and specificity of two risk classifications of obesity based on the body mass index (BMI). METHODS: Five-hundred and two adolescents, aged 12-18 years, participants of a health and nutrition survey conducted in 1996 in the city of Rio de Janeiro, Brazil, were evaluated. The study variables included: weight, stature, BMI, and subscapular skinfold, according to sex and age. The BMI classifications were compared to a fatness classification based on the 90th percentile of subscapular skinfold thickness in American adolescents. RESULTS: The prevalence of risk of obesity was higher when using the subscapular skinfold measurement (p<0.0001), compared to both BMI-based classifications, which showed similar values. Specificity was higher than sensitivity in both BMI-based classifications. The balance between sensitivity and specificity was close to the 70thBMI percentile for boys and girls below 14 years old. For boys older than 15 the cutoff value was the 50th percentile. CONCLUSION: Both BMI-based classifications were more suitable to identify adolescents without obesity, and their sensitivities were too low for tracking risk of obesity.

Teores de ácidos graxos trans de alguns alimentos consumidos no Rio de Janeiro

Elaborado a partir da tese de doutorado em Epidemologia de V.L.P. CHIARA, “Avaliacao Nutricional de Adolescentes comoInstrumento na Prevencao de Doencas Cardiovasculares”. Programa de Pos-Graduacao em Saude Coletiva – Area deConcentracao de Epidemiologia, do Instituto de Medicina Social, Universidade Estadual do Rio de Janeiro.

Atividade física e gestação: saúde da gestante não atleta e crescimento fetal

The benefits of physical activity on the life cycle are recognized but there is no consensus of physical activity when related to pregnancy. This article reviews aspects and effects of the practice of physical activities during pregnancy on non-athletic pregnant women and on the fetus. Medline and Pubmed were referred to in the period of 1992-2002. Among the benefits, the articles highlights: prevention and reduction of backaches, pains on hands and feet and cardiovascular stress, strengthening of pelvic muscles, reduction of premature deliveries and C-sections, more flexibility and tolerance to pain, ponderal gain control and increase of the self-esteem in pregnant women. As for the fetus there was improvement of weight and nutritional conditions. There were no recommendations of nutritional needs for non-athletic pregnant women. There was no consensus related to nutritional needs and the type of physical activities for pregnant women. Physical exercises in the water were considered more adequate. There are various counter-indications for exercises during pregnancy. The conclusion is that regular and moderate physical and controlled activities in the beginning of pregnancy are beneficial to mothers and fetuses.

Nutrição e excesso de massa corporal: fatores de risco cardiovascular em adolescentes

OBJECTIVE: To assess the frequency of arterial hypertension, inactivity and inadequate food intake related to cardiovascular risk in adolescents with excess body mass. METHODS: Cross-sectional study including 56 adolescents (21 boys and 35 girls) aged 10-19 years. Variables were: gender, age, weight, height, body mass index, nutritional classification, arterial hypertension, physical activity, and food intake categories scored in terms of cardiovascular risk. This intake was assessed through a questionnaire which established cardiovascular risk intake among adolescents by intake categories according to scored amounts and intake frequency. The questionnaire originated the variables intake categories and scores. Spearmans correlation was applied among body mass index, age and intake score. Students test compared body mass index averages, age, body mass, stature and intake score, according to gender; and the chi-square test assessed frequencies according to presence and absence of arterial hypertension, physical exercise practice and intake categories. The Kruskal-Wallis test analyzed the variation of intake scores among the groups. RESULTS: There was no statistical difference between genders in physical activity (p=0.68), arterial hypertension (p=0.94), body mass excess (p=0.31), or intake categories (p=0.53). Body mass index did not correlate with age (r=0.20, p=0.14) or intake score (r=-0.06, p=0.60). There was no statistical difference (p=0.19) in intake scores among the groups. CONCLUSION: Adolescents showed no gender differences concerning arterial hypertension prevalence, inactivity and food intake related to cardiovascular risk, although for girls these factors were more frequent when these were grouped.

Food consumption of adolescents. A simplified questionnaire for evaluating cardiovascular risk

OBJECTIVE To develop a simplified questionnaire for self-evaluation by adolescents of foods associated with the risk of coronary diseases. METHODS Frequency questionnaires about 80 foods were answered by representative samples of 256 adolescents aged 12 to 19 from Rio de Janeiro as part of the Nutrition and Health Research project. The dependent variable was the serum cholesterol predicting equation as influenced by diet, and the independent variables were the foods. The variables were normalized and, using Pearsons correlation coefficient, those with r>0.10 were selected for the regression model. The model was analyzed for sex, age, random sample, and total calories. Those food products that explained 85% of the cholesterol variation equation were present in the caloric model, and contained trans fatty acids were selected for the questionnaire. RESULTS Sixty-five food products had a statistically significant correlation (P<0.001) with the dependent variable. The simplified questionnaire included 9 food products present in all tested models: steak or broiled meat, hamburger, full-fat cheese, French fries or potato chips, whole milk, pies or cakes, cookies, sausages, butter or margarine. The limit of the added food points for self-evaluation was 100, and over 120 points was considered excessive. CONCLUSION The scores given to the food products and the criteria for the evaluation of the consumption limits enabled the adolescents to get to know and to balance their intake.

Ácidos graxos trans: doenças cardiovasculares e saúde materno-infantil

This article reviews the literature produced on the theme during the last decades, focusing on its effect on human metabolism, concerning coronary diseases and mother-child health. Trans fatty acids have been recently included among dietary risk factors for cardiovascular diseases. Their relation with the childs growing and developing processes, since fetal phase and gestational period, has also been discussed. Trans fatty acids originate from unsaturated fatty acids, in hydrogenation and biohydrogenation processes, and their action is different from the latter. Many works emphasize their hypercholesterolemic effect and influence on blocking and inhibiting biosynthesis of essential fatty acids. These actions reflect on mother-child health and increase the risk of cardiovascular diseases. The author recommends the consumption of food containing hydrogenated fat within the limits of 2-5% of trans fatty acids for total calories, as in other countries.

Redução de lista de alimentos para questionário de freqüência alimentar: questões metodológicas na construção

OBJETIVO: Reduzir lista de alimentos de um questionario de frequencia alimentar semiquantitativo atraves de diversas estrategias metodologicas, mantendo-se a capacidade de analise do consumo de energia, proteinas, glicidios, lipideos, calcio e ferro. METODOS: Utilizou-se um questionario de frequencia semiquantitativo com 80 itens alimentares respondidos por 224 meninas (12-19 anos). Reduziu-se a lista por regressao linear multipla, frequencia de consumo e composicao nutricional dos alimentos. Analisou-se por teste t de Student, sensibilidade de distribuicao das adolescentes por quartis de consumo, coeficiente Kappa e modelos de regressao. RESULTADOS: Os alimentos incluidos apresentaram coeficiente de regressao positivo, com valor de F significativo (P<0,001). As variâncias totais dos modelos foram superiores a 0,87, com alguns alimentos nao apresentando plausibilidade nos modelos. Selecionaram-se 32 alimentos dos modelos e 37 dentre os frequentemente consumidos. Os dois criterios apresentaram alguns alimentos distintos; quando os mesmos foram integrados, obtiveram-se 40 alimentos para lista reduzida. As medias de consumo nao diferiram entre a lista integral e a reduzida. As analises de sensibilidade variaram entre 85% e 100%. O grau de concordância foi significativo para todos os fatores dieteticos. Os modelos de regressao com a lista reduzida mantiveram variâncias totais acima de 0,85 e alimentos semelhantes aos anteriores. CONCLUSAO: Os criterios estabelecidos foram apropriados para reduzir a lista de 80 alimentos em 40, mantendo-se a capacidade de predicao e de avaliacao do consumo alimentar dos componentes investigados para o grupo populacional utilizado.

Correlação e concordância entre indicadores de obesidade central e índice de massa corporal em adolescentes

OBJETIVO: Analisar o desempenho de indicadores de obesidade central por correlacao e concordância com indice de massa corporal para avaliacao nutricional em adolescentes segundo sexo e idade. METODOS: Estudo seccional do tipo censo incluindo 635 adolescentes, de 10 a 19 anos (342 do sexo masculino e 293 do feminino), realizado em escola publica da cidade do Rio de Janeiro. Variaveis do estudo: indice de massa corporal (IMC), circunferencias de cintura e abdomen, razoes cintura-quadril e cintura/altura, estado nutricional, sexo e idade. Desenvolveram-se analise univariada e bivariada controlada por estratificacao. RESULTADOS: As circunferencias de cintura e abdomen correlacionaram-se positiva e significativamente (p < 0,05) com o IMC em ambos os sexos, faixa etaria e estado nutricional, enquanto a correlacao de razao cintura/altura foi influenciada por sexo e estado nutricional. Para razao cintura/quadril, a variacao do sentido da correlacao foi influenciada ainda por idade. As circunferencias de cintura e abdomen foram dependentes da variacao dos valores de IMC em todos os grupos com elevados R2 (0,66 a 0,80) e ² positivo, o que nao ocorreu para razoes cintura/quadril e cintura/altura. Somente a circunferencia de cintura apresentou agregamento moderado com o IMC (Indice Kappa de 0,41 a 0,57) em todos os estratos, enquanto nos demais indicadores o agregamento variou de relativo a moderado. CONCLUSOES: Dentre os indicadores de obesidade central analisados, as circunferencias de cintura e abdomen apresentaram os melhores desempenhos, destacando-se a circunferencia de cintura como mais apropriada para uso complementar ao IMC na avaliacao nutricional de adolescentes.

Artigos de revisão: contribuições com enfoque em ciência da nutrição

O objetivo deste trabalho e contribuir com a producao cientifica de artigos de revisao com base em pesquisasquantitativas, cuja finalidade e atualizacao do conhecimento sobre determinado tema, dirigindo-seespecialmente aos pesquisadores iniciantes. Aborda a utilizacao de alguns instrumentos teorico-metodologicospara producao de textos, a priorizacao nos cuidados necessarios quanto a leitura dos artigos consultados, oenriquecimento do conhecimento e a forma de reproducao desse conhecimento adquirido. Tambem alertapara os diversos aspectos que podem envolver a discussao sobre o tema escolhido, ressaltando e exemplificandoa abrangencia dos recursos metodologicos que precisam ser respeitados, mesmo em artigos de revisao deliteratura. Conclui, orientando o compromisso com a qualidade que o desenvolvimento da pesquisa exige, ea preparacao do material resultante da mesma em forma de pesquisa cientifica.