Serum Homocysteine and Cysteine Levels and Anthropometric Changes: A Longitudinal Study among Brazilian Children and Adolescents.

OBJECTIVE: This article aimed to identify the influence of high serum homocysteine (Hcy) and cysteine (Cys) levels, alone or in conjunction, on changes in anthropometric parameters in children and adolescents over a 12-month follow-up period. METHODS: This is a cohort study involving 483 boys and girls 7-15 years of age. The outcome variables were body mass index (BMI)-for-age and waist circumference (WC) and the principal exposure variables were serum Hcy and Cys levels, alone or in conjunction. A generalized estimating equation (GEE) approach was used to identify longitudinal changes in the outcome variables. RESULTS: Irrespective of age, sex, socioeconomic conditions, dietary intake, or the practice of physical activity, the children and adolescents in the fifth quintile of distribution of Hcy levels had a z-score increase of 0.50 (p < 0.01) and a 3.62 cm increase (p < 0.01) in mean BMI-for-age and WC, respectively, over the period of the study. In individuals with Cys values above the fifth quintile, a z-score increase of 0.59 (p < 0.01) and a 5 cm increase (p < 0.01) were found in BMI-for-age and WC, respectively. When serum Hcy and Cys levels were both above the fifth quintile of distribution, a z-score increase of 0.87 (p < 0.01) and a 6.57 cm increase (p < 0.01) were found in mean BMI-for-age and WC, respectively, over the 12-month follow-up. CONCLUSION: High serum Hcy and Cys levels contributed to an increase in BMI-for-age and WC in children and adolescents over a 12-month follow-up period, with these increases being even greater when these 2 biochemical parameters were simultaneously high.

Effect of city-wide sanitation programme on reduction in rate of childhood diarrhoea in northeast Brazil: assessment by two cohort studies.

BACKGROUND: A city-wide sanitation intervention was started in Salvador, Brazil, in 1997 to improve sewerage coverage from 26% of households to 80%. Our aim was to investigate the epidemiological effect of this city-wide sanitation programme on diarrhoea morbidity in children less than 3 years of age. METHODS: The investigation was composed of two longitudinal studies done in 1997-98 before the intervention (the sanitation programme) and in 2003-04 after the intervention had been completed. Each study consisted of a cohort of children (841 in the preintervention study and 1007 in the postintervention study; age 0-36 months at baseline) who were followed up for a maximum of 8 months. Children were sampled from 24 sentinel areas that were randomly chosen to represent the range of environmental conditions in the study site. At the start of each study an individual or household questionnaire was applied by trained fieldworkers; an environmental survey was done in each area before and after introduction of the sanitation programme to assess basic neighbourhood and household sanitation conditions. Daily diarrhoea data were obtained during home visits twice per week. The effect of the intervention was estimated by a hierarchical modelling approach fitting a sequence of multivariate regression models. FINDINGS: Diarrhoea prevalence fell by 21% (95% CI 18-25%)-from 9.2 (9.0-9.5) days per child-year before the intervention to 7.3 (7.0-7.5) days per child-year afterwards. After adjustment for baseline sewerage coverage and potential confounding variables, we estimated an overall prevalence reduction of 22% (19-26%). INTERPRETATION: Our results show that urban sanitation is a highly effective health measure that can no longer be ignored, and they provide a timely support for the launch of 2008 as the International Year of Sanitation.

Determinants of cognitive function in childhood: a cohort study in a middle income context.

BACKGROUND: There is evidence that poverty, health and nutrition affect children's cognitive development. This study aimed to examine the relative contributions of both proximal and distal risk factors on child cognitive development, by breaking down the possible causal pathways through which poverty affects cognition. METHODS: This cohort study collected data on family socioeconomic status, household and neighbourhood environmental conditions, child health and nutritional status, psychosocial stimulation and nursery school attendance. The effect of these on Wechsler Pre-School and Primary Scale of Intelligence scores at five years of age was investigated using a multivariable hierarchical analysis, guided by the proposed conceptual framework. RESULTS: Unfavourable socioeconomic conditions, poorly educated mother, absent father, poor sanitary conditions at home and in the neighbourhood and low birth weight were negatively associated with cognitive performance at five years of age, while strong positive associations were found with high levels of domestic stimulation and nursery school attendance. CONCLUSION: Children's cognitive development in urban contexts in developing countries could be substantially increased by interventions promoting early psychosocial stimulation and preschool experience, together with efforts to prevent low birth weight and promote adequate nutritional status.

[Inequality, poverty, and childhood health and nutritional conditions in Northeast Brazil]. / Desigualdade, pobreza e condições de saúde e nutrição na infância no Nordeste brasileiro.

This cross-sectional study analyzes the relationship between gradients of social inequalities and the household environment and health and nutritional conditions among 2,001 preschool children in ten counties (municipalities) in the State of Bahia, Brazil. The analysis used multinomial multivariate logistic regression. Children in the middle and lower tertiles on the poverty scale had significant and increasing odds of living in a household headed by a woman, an unemployed father, a mother with

[Determinants of linear growth retardation in Brazilian preschool children: a multilevel approach]. / Preditores do retardo de crescimento linear em pré-escolares: uma abordagem multinível.

This study focuses on the determinants of linear growth deficit in under-five children using multilevel modeling. The sample included 3,746 preschoolers from 15 Brazilian municipalities (ten from the State of Bahia and five from São Paulo), with a three-tier analysis (municipalities, households, and children). Municipal data were obtained from the 1991 National Census. Individual and household data were collected from 1999 to 2001 using structured questionnaires and measuring children's weight and height. Analysis used the MLwiN software. In the final multilevel model, low HDI and prenatal care at the municipal level, poor environmental and economic conditions and maternal schooling at the household level, and low birth weight, incomplete immunization, prior history of malnutrition, and no report of breastfeeding at the individual level were strongly associated with linear growth deficit. Total variability of deficit explained by the model was 27.4%, of which 51.3%, 33%, and 15.7% were explained, respectively, by individual, household, and municipal variables.

Validity and reliability of the sagittal abdominal diameter as a predictor of visceral abdominal fat.

OBJECTIVES: To evaluate the reliability of the sagittal abdominal diameter and its validity as a predictor of visceral abdominal fat, as well as to identify the most appropriate cut-off points to identify the area of visceral fat that is known to represent a risk factor for cardiovascular disease. DESIGN: Validation study. SUBJECTS: 92 healthy volunteers (57 women, 35 men), age: 20-83 y, body mass index: 19.3 to 35.9 kg/m2. MEASUREMENTS: Sagittal abdominal diameter (SAD), weight, height, circumferences (waist, hip, and thigh), sub-scapular skinfold thickness, abdominal diameter index, and waist-hip ratio (WHR). METHOD OF CHOICE: Computed tomography (CT). STATISTIC: Receiver operating characteristic (ROC) curve. RESULTS: The reliability for SAD measurement was very high (Inter-class coefficient = 0.99). Visceral fat as measured by VAF through CT was highly correlated with SAD (women r = 0.80; men r = 0.64, p < 0.001), waist circumference (women r = 0.77; men r = 0.73, p < 0.001), and WHR (women r = 0.72; men r = 0.58, p < 0.001). The ROC curve indicated 19.3 cm and 20.5 cm as the threshold values for abdominal sagittal diameter in women and men (sensitivity 85% and 83%, specificity 77% and 82%, respectively). CONCLUSIONS: There was a high correlation between SAD and VAF. The cut-off values identified for SAD presented a sensitivity and specificity that were considered adequate.

Moderate- and low-intensity co-infections by intestinal helminths and Schistosoma mansoni, dietary iron intake, and anemia in Brazilian children.

To determine the role of moderate- and low-intensity infections with Schistosoma mansoni and intestinal helminths (hookworm, Trichuris trichiura, Ascaris lumbricoides) on the prevalence of anemia and their relationship to iron consumption, a cross-section of 1,709 children in rural Brazil was studied. All participants were selected for infection with one or multiple helminthic parasites, and demographic, anthropometric, and dietary intake were surveyed. The prevalence and intensity were as follows: hookworm infection, 15.7% and 8.6 eggs/g; T. trichiura, 74.8% and 190.5 eggs/g; A. lumbricoides, 63% and 1,905.5 eggs/g; S. mansoni, 44.5% and 60.3 eggs/g. There was no increase in odds ratio for anemia with any combination of intestinal helminths without S. mansoni infection. By logistic regression, the odds ratio for having anemia when infected with S. mansoni and two intestinal helminths was 1.7 (95% CI, 1.1-2.5) and for S. mansoni and three intestinal helminths was 2.4 (95% CI, 1.2-4.6) compared with children with a single parasite species. Children with an adequate intake of iron had no increased odds of anemia independent of the combination of parasite infections.

Biochemical and immunologic predictors of efficacy of treatment or reinfection risk for Schistosoma mansoni.

Most Schistosoma mansoni infections are egg-negative after a single dose of oxamniquine. A cohort of 661 infected children was treated at 6-month intervals and assessed for nutritional and parasitological status. Initial biochemical and immunologic markers were measured in a subset of 84 children. All were treated at the start of therapy and at 6 months. Immunoglobulins only served as markers for active infection. No markers were predictive of cure or reinfection, except initial infection intensity and serum low-density lipoprotein. Ten percent were persistently infected and had no change in infection intensity at any time-point. Several factors suggest that this group was biologically different. In addition to failing to reduce their worm burden, they had significantly higher initial intensity of infection (100 versus 65 eggs/g, P = 0.001) and significantly lower initial serum low-density lipoprotein (72 versus 104 mg/dL, P = 0.045). The biologic plausibility of this observation is discussed.

[Breastfeeding duration, infant feeding regimes, and factors related to living conditions in the city of Salvador, Bahia, Brazil]. / Duração do aleitamento materno, regime alimentar e fatores associados segundo condições de vida em Salvador, Bahia, Brasil.

This cross-sectional study aimed to identify breastfeeding duration, infant feeding regimes, and factors related to living conditions among 811 children under 24 months of age in Salvador, Bahia, Brazil. Data were statistically analyzed by survival analysis, Pearson's chi-square test, and multivariate logistic regression. Median duration of exclusive, predominant, and total breastfeeding was 30.6, 73.0, and 131.5 days, respectively. Exclusive or predominant breastfeeding was discontinued in 83.6% of the subjects. Children with poor living conditions were 2.3 times more likely (95%CI: 1.09-5.01) to receive early supplementary food, whereas the figure for the very poor increased to 2.5 (95%CI: 1.20-5.34). Early exclusive or predominant breastfeeding discontinuation was associated with early pregnancy and poor living conditions of the children and their families. Programs directed towards proper breastfeeding and healthy feeding practices in childhood should consider the social factors associated with early introduction of supplementary foods in this population.

Childhood anemia prevalence and associated factors in Salvador, Bahia, Brazil.

A cross-sectional study was conducted in 1996 to estimate the prevalence of anemia in a stratified sample of 603 preschool children and identify factors associated with the disease. Hemoglobin assays were conducted in finger-prick blood samples using a Hemocue hemoglobinometer. Anemia was defined as hemoglobin below 11.0 g/dl. Logistic regression analysis was used to evaluate the potential associations. Observed anemia prevalence was 46.3%. Associated factors were: the 6-12-month and 12-24-month age brackets, the lowest tertiles for iron density and protein content dietary intake, and any degree of deficit in the height-for-age anthropometric parameter. Inadequate physical, sanitary, and environmental conditions in the home were associated with a significantly increased risk of anemia. Anemia constitutes an important health problem in this study's child population. Improvements in living conditions and dietary quality could contribute to a reduction in anemia prevalence.