Ana Marlucia de Oliveira Assis

Multi-country analysis of the effects of diarrhoea on childhood stunting

Diarrhoea is an important cause of death and illness among children in developing countries; however, it remains controversial as to whether diarrhoea leads to stunting. We conducted a pooled analysis of nine studies that collected daily diarrhoea morbidity and longitudinal anthropometry to determine the effects of the longitudinal history of diarrhoea prior to 24 months on stunting at age 24 months. Data covered a 20-year period and five countries. We used logistic regression to model the effect of diarrhoea on stunting. The prevalence of stunting at age 24 months varied by study (range 21-90%), as did the longitudinal history of diarrhoea prior to 24 months (incidence range 3.6-13.4 episodes per child-year, prevalence range 2.4-16.3%). The effect of diarrhoea on stunting, however, was similar across studies. The odds of stunting at age 24 months increased multiplicatively with each diarrhoeal episode and with each day of diarrhoea before 24 months (all P < 0.001). The adjusted odds of stunting increased by 1.13 for every five episodes (95% CI 1.07-1.19), and by 1.16 for every 5% unit increase in longitudinal prevalence (95% CI 1.07-1.25). In this assembled sample of 24-month-old children, the proportion of stunting attributed to >or=5 diarrhoeal episodes before 24 months was 25% (95% CI 8-38%) and that attributed to being ill with diarrhoea for >or=2% of the time before 24 months was 18% (95% CI 1-31%). These observations are consistent with the hypothesis that a higher cumulative burden of diarrhoea increases the risk of stunting.

Effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections in young children in Brazil

A beneficial effect of periodic vitamin A supplementation on childhood mortality has been demonstrated, but the effect on morbidity is less clear. We investigated the effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections (ALRI) in children from northeastern Brazil in a randomised, double-blind, placebo-controlled community trial. 1240 children aged 6-48 months were assigned vitamin A or placebo every 4 months for 1 year. They were followed up at home three times a week, and data about the occurrence and severity of diarrhoea and ALRI were collected. Any child with cough and respiratory rate above 40 breaths per min was visited by a paediatrician. The overall incidence of diarrhoea episodes was significantly lower in the vitamin-A-supplemented group than in the placebo group (18.42 vs 19.58 x 10(-3) child-days; rate ratio 0.94 [95% Cl 0.90-0.98]). The benefit of supplementation was greater as regards severe episodes of diarrhoea; the incidence was 20% lower in the vitamin A group than in the placebo group (rate ratio 0.80 [0.65-0.98]). With the standard definition of diarrhoea (> or = 3 liquid or semi-liquid stools in 24 h) the effect of vitamin A on mean daily prevalence did not reach significance, but as the definition of diarrhoea was made more stringent (increasing number of stools per day), a significant benefit became apparent, reaching for diarrhoea with 6 or more liquid or semi-liquid stools in 24 h a 23% lower prevalence. We found no effect of vitamin A supplementation on the incidence of ALRI. The reduction in severity of diarrhoea may be the most important factor in the lowering of mortality by vitamin A supplementation.

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

Summary 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.

Obesity and vitamin D deficiency: a systematic review and meta‐analysis

Over the past decade, there have been an increasing number of studies on the association between vitamin D deficiency and anthropometric state. However, we did not identify any meta‐analyses of the relationship between obesity and vitamin D deficiency in different age groups. Thus, we evaluated the association between obesity and vitamin D deficiency. We searched for observational studies published up to April 2014 in PubMed/Medline, Web of Science and Scopus databases. We performed a meta‐analysis in accordance with the random‐effects model to obtain the summary measurement (prevalence ratio, PR). Among the 29,882 articles identified, 23 met the inclusion criteria. The prevalence of vitamin D deficiency was 35% higher in obese subjects compared to the eutrophic group (PR: 1.35; 95% CI: 1.21–1.50) and 24% higher than in the overweight group (PR: 1.24; 95% CI: 1.14–1.34). These results indicate that the prevalence of vitamin D deficiency was more elevated in obese subjects. The vitamin D deficiency was associated with obesity irrespective of age, latitude, cut‐offs to define vitamin D deficiency and the Human Development Index of the study location.

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.

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

BackgroundThere is evidence that poverty, health and nutrition affect childrens 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.MethodsThis 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.ResultsUnfavourable 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.ConclusionChildrens 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.

Impact of a citywide sanitation program in Northeast Brazil on intestinal parasites infection in young children.

Background Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households. Objectives We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children. Methods The evaluation was composed of two cross-sectional studies (1998 and 2003–2004), each of a sample of 681 and 976 children 1–4 years of age, respectively. Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site. Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions. Stool samples were examined for the presence of intestinal parasites. The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models. Findings The prevalence of A. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%. Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention. The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain. Conclusion This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population.

Alimentação complementar nos primeiros dois anos de vida

Este e um estudo transversal, com amostra constituida de 724 criancas residentes na cidade de Salvador, BA,Brasil, elegiveis por meio de amostragem por conglomerados em tres estagios. As informacoes referentes aoconsumo alimentar foram coletadas por meio do inquerito recordatorio de 24 horas e processadas peloprograma

Fatores associados a excesso de peso e concentração de gordura abdominal em adultos na cidade de Salvador, Bahia, Brasil

O objetivo foi identificar os fatores associados ao excesso de peso e concentracao de gordura abdominal em adultos de ambos os sexos. Um estudo transversal envolvendo amostra representativa de 570 adultos de Salvador, Bahia, Brasil. A regressao de Poisson foi utilizada na analise, adotando-se o indice de massa corporal (IMC) e a circunferencia da cintura como variaveis dependentes. Para as mulheres, a inadequacao do IMC e da circunferencia da cintura ocorreu com o aumento da idade e entre as que faziam dieta no momento do estudo, a historia familiar de obesidade associou-se apenas com o IMC elevado. Para os homens, o IMC elevou-se na faixa etaria de 30 a 39 e 50 a 59 anos. A circunferencia da cintura elevou-se com a realizacao de tres ou menos refeicoes-dia, com a hipertensao arterial, uso de bebida alcoolica e diminuiu entre mulatos e negros. Tanto IMC quanto circunferencia da cintura elevaram-se com a historia familiar de infarto. Portanto sao distintos os fatores que se associam ao excesso de peso e da gordura abdominal em homens e mulheres. Mas muitos deles podem ser modificados com a adocao do estilo de vida saudavel.

Fatores associados à anemia em crianças e adolescentes de escolas públicas de Salvador, Bahia, Brasil

This study aimed to assess factors associated with anemia in schoolchildren. All subjects (N = 1,013; age 7-14 yrs.) were students enrolled in the public school system in Salvador, Bahia State, Brazil. Blood tests were done to determine hemoglobin levels, anthropometric data were collected, and a 24-hour food recall was performed. The study also gathered socioeconomic, environmental, and household data, as well as information on care by the mother. Anemia was detected in 24.5% of subjects, with mean hemoglobin of 12.68g/dL (range 7.7g-16.8g/dL). Anemia was significantly associated with inadequate intake of bioavailable iron (OR50-99.9% adequacy = 1.57; 95%CI: 1.07-2.29; p = 0.020 and OR< 50% adequacy = 1.68; 95%CI: 1.10-2.56; p = 0.016) and family income below 1 minimum wage (OR = 1, 42; 95%CI: 1.03-1.96; p = 0.035). Anemia prevalence in children and adolescents was high, especially among the poorest subjects and those with low intake of bioavailable iron.