Silvia Nascimento de Freitas

Association between nutritional status, food habits and physical activity level in schoolchildren

OBJECTIVES To analyze the relation between nutritional status, food habits and physical activity level in schoolchildren. METHODS A cross-sectional study was carried out with 661 schoolchildren, from 6 to 14 years old, enrolled in public and private schools located in the urban area of Ouro Preto, state of Minas Gerais, Brazil. A semi-structured questionnaire was applied to collect data on demographic, socio-economic, anthropometric and level of physical activity variables. Schoolchildren were classified according to criteria for body mass index by age, body fat percentage and physical activity level, respectively. Dietary data were collected through a validated food frequency questionnaire specific for children and adolescents. Food consumption was evaluated according to an adaptation of the Recommended Foods Score, whose objective is the assessment of overall diet quality with a focus on healthy food consumption. RESULTS We observed high frequency of overweight according to body mass index per age (20.1%) and body fat percentage (22.8%), as well as physical inactivity (80.3%) among schoolchildren. We also found low scores on the Recommended Foods Score in 77.2% of students. There was no significant relation between overweight and physical inactivity or food consumption (p > 0.05). CONCLUSION Schoolchildren had a high frequency of overweight, which, alone, was not associated with the high physical inactivity and the low quality diet observed. Therefore, more studies should be performed to identify other factors besides those already described, which may be influencing overweight in this population.

Apolipoprotein E polymorphism in Brazilian dyslipidemic individuals: Ouro Preto study

The influence of apolipoprotein E alleles and genotypes on plasma lipid levels was determined in 185 individuals of mixed ethnicity living in Ouro Preto, Brazil. DNA was obtained from blood samples and the genotypes were determined by an RFLP-PCR procedure. The *3 allele was the most frequent (72%), followed by *4 (20%) and *2 (8%); *4 frequency was higher and *2 frequency was lower in the dyslipidemic group than in the normal control group. The *2 carriers presented lower LDL and total cholesterol levels compared to the *3 and *4 carriers. All six expected genotypes were observed in the individuals genotyped: E2/2 (2.1%), E4/4 (2.7%), E2/4 (3.7%), E2/3 (8.0%), E3/3 (53.3%), E3/4 (29.9%); no difference in genotype frequencies was found between the normal and dyslipidemic groups. Compared with *2, the presence of *3 increases more than two times the risk for dyslipidemia (OR = 2.31; P = 0.025; 95% CI = 1.06-5.06) and the presence of *4 increases it three times (OR = 3.31; P = 0.006; 95% CI = 1.36-8.04). The only significant effect of genotype was an increased risk for dyslipidemia in the *4 genotype carriers (E3/4 + E4/4) compared with the *2 genotype carriers (E2/2 + E2/3) with OR = 3.69 (95% CI = 1.25-10.88). The present study indicates that in the Ouro Preto admixed population the presence of APOE *2 can confer a protective effect, whereas the presence of APOE *4 implies an enhanced risk for dyslipidemia.

Práticas de amamentação no município de Ouro Preto, MG, Brasil

OBJETIVO: Conhecer a frequencia e a duracao mediana das praticas de aleitamento materno em criancas de 0-24 meses no municipio de Ouro Preto, MG. METODOS: Estudo epidemiologico tipo transversal em amostra estratificada de 229 criancas provenientes de 1.800 domicilios, visitados em 1996 e sorteados por conglomerado em tres estagios. A frequencia e a duracao mediana das praticas foram calculadas mediante tabua de vida. RESULTADOS: A duracao mediana da amamentacao foi de 198 dias, sendo de 71 dias para a amamentacao exclusiva somada a predominante e 17 dias para a amamentacao exclusiva. CONCLUSAO: Embora a maioria das maes amamente seus filhos ao nascer, a introducao de outros alimentos ainda e bastante prematura, fato que justifica a necessidade de intervencoes para prevenir o desmame parcial e/ou total precoce.

Ingestão de cálcio e indicadores antropométricos entre adolescentes

OBJETIVO: Este estudo teve como objetivo investigar a relacao da ingestao de calcio com indicadores antropometricos de adolescentes. METODOS: Foram avaliados 507 alunos de duas escolas publicas e uma particular de Ouro Preto, Minas Gerais, por meio de questionario sobre condicoes socioeconomicas, avaliacao da maturacao sexual, antropometria, composicao corporal e consumo alimentar. RESULTADOS: A ingestao media de calcio foi 703,7 (396,0) mg/dia, sendo a maior ingestao verificada na escola de maior nivel socioeconomico. Apenas 8% dos adolescentes apresentavam ingestao superior a ingestao adequada. Houve associacao negativa do calcio, ajustado para o indice de massa corporal (r=-0,203, p=0,001), na escola de medio nivel socioeconomico e nos adolescentes com ingestao desse mineral entre 400 e 800mg/dia (r=-0,134, p=0,044). CONCLUSAO: Verificou-se ingestao insuficiente de calcio entre os adolescentes de Ouro Preto, evidenciando a necessidade de estimular o consumo de alimentos fontes desse mineral nesta populacao.

Anthropometric measurements and obesity diagnosis in schoolchildren.

Aim:  To evaluate whether anthropometric methods such as arm muscle area, arm fat area, Rohrer index, conicity index, and waist‐to‐height ratio and the commonly used body mass index method are suitable for obesity screening in a multiethnic paediatric population.

Anthropometric methods for obesity screening in schoolchildren: the Ouro Preto Study

BACKGROUND AND AIMS Childhood obesity is increasing dramatically in last decades. To evaluate the usefulness of body mass index (BMI), skinfold thickness (ST), waist circumference (WC), and foot-to-foot bioelectrical impedance (BIA-FF) for screening for obesity in mixed-race population, using the tetrapolar bioelectrical impedance (BIA-T) technique as reference method. METHODS AND RESULTS A cross-sectional-based population study was performed in the city of Ouro Preto, Brazil, in 2006. Schoolchildren aged 6-15 years (n = 788) was randomly selected according to age and sex stratified by the proportion of students in each schools of the city. Nonparametric receiver operating characteristic (ROC) analysis was used to define the sensitivity and specificity for each method studied using the tetrapolar method as reference. The BMI and the BIA-FF were the most suitable for adiposity screening in pre-pubertal and pubertal stages because they present a better balance between sensitivity and specificity, and smaller misclassification. For post-pubertal boys, the BF-ST-D was the best body fat assessment method. CONCLUSION The results suggest that BIA-FF and BMI are choice methods for obesity screening in mixed population and that the method choice for body fat screening must be done according to sexual maturity of boys and girls. The present study demonstrates the need to perform studies in wider mixed-race population to determine anthropometric parameters and to examine the predictive ability of methods and cut-offs here elucidated in the development of obesity.

A comparative study of methods for diagnosis of obesity in an urban mixed-race population in Minas Gerais, Brazil.

BACKGROUND Obesity is defined as an excess of total body fat and may be assessed by different methods. The objective of the present study was to establish the discriminatory power of anthropometric data in determining obesity. METHODS The subjects comprised 685 individuals, aged 20-79 years, sampled from a population-based survey. The following indicators were used: body mass index (BMI), waist circumference (WC) and total body fat percentage estimated with both Siris equation (%BF Siri) and foot-to-foot bioelectrical impedance analysis (%BF BIA). Sensitivity and specificity of different cut-off points for each method were determined using %BF BIA as reference. RESULTS Of 685 participants, 57.6% were aged >/= 40 years, 69.9% were women and 72.6% self-referred themselves as non-white. To classify obesity based on sex and age among women aged 0.05). Classifying according to skin colour did not change cut-off points in any indicator. CONCLUSION BMI and WC better discriminate obesity among women and men aged >/= 40 years from a mixed-race population.

Heart rate variability in shift workers: responses to orthostatism and relationships with anthropometry, body composition, and blood pressure.

In order to investigate the response of heart rate variability (HRV) components to postural change and their association with cardiovascular risk factors in shift workers, a cross-sectional study with 438 Brazilian males rotating shift workers was done. Anthropometric, body composition, and clinical measures were collected. Electrocardiogram was recorded for 3 minutes, in the supine and orthostatic position, and HRV components were extracted. Descriptive analyses showed that mean values of body mass index, waist circumference (WC), waist-to-height ratio, visceral fat area (VFA), and blood pressure (BP) were higher than the reference values. In the regression model, age, WC, VFA, and systolic BP showed negative association with HRV components. These findings suggest the need for determining effective strategies for the evaluation and promotion of health among shift workers focused on the altered variables.

Tempo de aleitamento materno entre indígenas Xakriabá aldeados em Minas Gerais, Sudeste do Brasil

OBJECTIVE: To estimate the median duration of breastfeeding in the Xakriaba Indigenous lands and identify the factors related to breastfeeding duration among these people. METHODS: A cross-sectional study was conducted, and data regarding health, breastfeeding, and socio-demographic characteristics of 342 mothers/children living in this Indigenous Land in Minas Gerais in 2007 were collected using a questionnaire. Descriptive data of 317 children who were breastfed for at least one day were obtained, but in order to achieve this study objective, only the questionnaires that were fully completed and referred to children who were breastfed for at least one day were analyzed, i.e., 82.2% (287 children) of the total population of indigenous children under 3 years old (349). Data were analyzed using the Kaplan Meier method and the Cox regression model. RESULTS: The majority of children were male (52.0%), 53.6% were the 1st, 2nd, or 3rd born child, and 94.6% were breastfed as the first form of nutrition. The median duration of exclusive breastfeeding and non-exclusive breastfeeding was 11.73 months and 7.27 days, respectively; the boys and the 4th or further children were weaned earlier. CONCLUSION: In the Xakriaba Indigenous Land, the median duration of exclusive breastfeeding is short and half of the children were weaned at around 12 months of age, and therefore they could no longer reap the nutritional, immunological and functional benefits provided by breast milk. Gender and birth order were associated with the duration of breastfeeding, but further studies are needed to better understand the sociocultural factors related to the duration of breastfeeding in this Indigenous Land.

Association between nutritional status, C-reactive protein, adiponectin and HOMA-AD in Brazilian children

INTRODUCTION In children, the presence of obesity is a major risk factor for the occurrence of cardiovascular diseases on the adulthood. OBJECTIVE To evaluate the association of anthropometry, body composition, clinical variables and biochemical profile with C-reactive protein and adiponectin levels, and insulin resistance in children in the municipality of Nova Era, Brazil. METHODS Nested case-control study following a crosssectional study. We evaluated 178 children, 57 of them classified as obese and 121 as normal-weight from a population of 1024 schoolchildren 6 to 10 years old: Blood samples were collected after 12-hour fast to obtain serum and plasma. We collected anthropometric and body composition measures, systolic and diastolic blood pressure data. Sexual maturation was assessed according to the stage of sexual development. We performed Students t-test, Mann-Whitney U test, Pearsons correlation, Spearmans test and multiple linear regression analysis. Independent variables with p < 0.05 were included in the multiple regression model. Residual analysis was performed to assess model validity. RESULTS Among obese children, C-reactive protein levels were associated with triacylglycerol levels and body fat percentage estimated by skinfold thickness (R2 adjusted = 27.6%, p < 0.001). Adiponectin was associated with HOMA-IR, HOMAAD and body fat percentage estimated by skinfold thickness (R2 adjusted = 75.5%, p < 0.001). HOMA-AD index was associated with HOMA-IR, adiponectin, systolic blood pressure and weight (R2 adjusted = 90.7%, p < 0.001). CONCLUSION Significant associations were found between body composition, anthropometry, clinical variables, biochemical profile and adiponectin and C-reactive protein levels and insulin resistance in obese and normal-weight children.