Luis Eduardo Castro

Socioenvironmental Conditions and Nutritional Status in Urban and Rural Schoolchildren

We analyzed the nutritional status of urban and rural schoolchildren from Mendoza (Argentina), but avoided rural and urban categorization by generating subpopulations as a function of their socioenvironmental characteristics. We transformed weight and height data into z‐scores using the CDC/NCHS growth charts; defined underweight, stunting, and wasting by z‐scores of less than −2 SD; and calculated overweight and obesity, according to the cutoff proposed by the International Obesity Task Force. Socioenvironmental characteristics included housing, public services, parental resources, and farming practices; we processed these variables by categorical principal‐component analysis. The two first axes defined four subgroups of schoolchildren: three of these were associated with urban characteristics, while the remaining subgroup was considered rural. Nutritional status differed across groups, whereas overweight was similar among the groups and obesity higher in urban middle‐income children. Urban differences were manifested mainly as underweight, but rural children exhibited the greatest stunting and wasting. Thus, the negative effects of environment on nutritional status in children are not restricted to poor periurban and rural areas, though these are indeed unfavorable environments for growth: some urban families provide children with sufficient quantity and diversity of foods to expose them to obesity. By contrast, the more affluent urban families would appear to have greater possibilities for allowing their children to adopt a healthy life‐style. Although the causes of differences in nutritional status between middle‐ and high‐income urban groups are not clear, these determinants probably involve economic as well as educational influences. Am. J. Hum. Biol., 2008.

ESTADO NUTRICIONAL Y PARASITOSIS INTESTINALES EN NIÑOS RESIDENTES EN ZONAS URBANA, PERIURBANA Y RURAL DEL PARTIDO DE BRANDSEN (BUENOS AIRES, ARGENTINA)

Carta a los directores de la publicacion en referencia a algunos aspectos de la nota citada.

Growth of school children in different urban environments in Argentina

Background: Nutritional transition has been described in various countries, each showing inherent characteristics. Furthermore, different patterns also appear within the same country. Aim: To compare the nutritional status of schoolchildren, of both sexes, living in two Argentine cities with different urban and environment characteristics, from the perspective of nutritional transition. Subjects and methods: The sample comprised 5355 children (6–13 years) living in Puerto Madryn (Chubut) and General Alvear (Mendoza), Argentina. Weight and height were transformed into Z-scores according to NHANES I- II; underweight, stunting and wasting defined by − 2 SD and overweight and obesity calculated according the cut-off proposed by IOTF. Prevalences of nutritional status were estimated. Results: Comparison of the two cities revealed significant χ2 values for the indicators of nutritional status analysed. Puerto Madryn had higher prevalences of overweight and obesity. General Alvear exhibited higher stunting and underweight values. Conclusions: The cities studied are in different stages of nutritional transition. Puerto Madryn is undergoing growing industrialization and urbanization and thus exhibits characteristics typical of an ‘obesogenic’ environment. General Alvear, a less complex urban centre, where some cultural patterns related to an agrarian way of life appear to have been retained, is situated at a less advanced stage.

Growth of functional cranial components in rats with intrauterine growth retardation after treatment with growth hormone

The goal of this study was to analyse the effect of growth hormone (GH) on catch-up growth of functional facial (splanchnocranial) and neurocranial components in rats with intrauterine growth retardation (IUGR). Wistar rats were divided into the following groups: control (C), sham-operated (SH), IUGR, and IUGR + GH. IUGR was surgically induced and GH was administered between 21 and 60 days of age. Radiographs were obtained at 1, 21, 42, 63, and 84 days of age in order to measure length, width, and height of neurocranium (NL, NW, and NH) and face length, width, and height (FL, FW, and FH). Analysis of variance was performed at 1 day of age and a principal components analysis (PCA) at 84 days of age. Neurocranial and facial volumetric indexes were calculated as NVI = (3)√NL × NW × NH and FVI = (3)√FL × FW × FH, respectively, and adjusted by non-linear regression analysis. On postnatal day 1, there were significant differences between SH and IUGR (P < 0.01). Also, in both genders, final neurocranial volume was similar between SH and IUGR + GH groups, while the IUGR group had the lower value (P < 0.01). Final facial volume was similar among the three groups. In both genders, facial growth rates were SH = IUGR > IUGR + GH (P < 0.01). The first axis of the PCA exhibited size effect and the second axis showed shape effect. Reductions of placental blood flow modify cranial growth. The functional neurocranial and facial components in rats with IUGR presented different recovery strategies through modular behaviour, mainly related to modifications of growth rate as response to GH administration.

Secular changes in body size and body composition in schoolchildren from La Plata City (Argentina)

AIM To analyze the secular changes in body size and composition of two cohorts of children from La Plata City, Argentina, with a 35-year follow-up. subjects and methods: Cohort 1 (C1) was measured in 1969-1970 and included 1772 children (889 boys, 883 girls), and Cohort 2 (C2), measured in 2004-2005, included 1059 children (542 boys, 517 girls). Both cohorts were obtained from matching geographical areas and comprised children from 4 to 12 years. Body weight (W); Height (H); Upper arm circumference (UAC); Tricipital (TS) and Subscapular skinfolds (SS) were measured, and Body Mass Index (BMI) and muscle (UMA) and fat (AFA) brachial areas were calculated. Prevalence of overweight and obesity was estimated by IOTF. To compare C1-C2 we used a generalized linear model with log-transformed variables, and chi square test. RESULTS There were significant and positive differences between C2-C1 in W, UAC, SS, TS, and AFA. In contrast, H was not significantly different and UMA was significantly different but with negative values. The prevalence of overweight and obesity was 14.5% and 3.8% in C1, and 17.0% and 6.8% in C2. Differences between cohorts were significant for obesity. CONCLUSION The shifts observed for soft tissues--positive trend for fat and negative for muscle area--occurring without changes in height lead us to suppose that in these three decades, La Platas population has experienced deterioration in living conditions and important changes in their lifestyle, such as an increased consumption of energy-dense foods and sedentary habits.

Bone growth and sexual dimorphism at birth in intrauterine-growth-retarded rats

This paper addresses the effect of a reduction of uterine blood flow (RUB) on postcranial bone growth in rats. The objectives were: (1) to discover and characterize the changes evoked by growth retardation through a reduction in placental blood flow, (2) to see if the resulting growth retardation is different in each bone, and (3) to analyze any sex-specific features. RUB was induced by the partial bending of uterine vessels at day 1 of pregnancy. Control and sham-operated animals were also included. The animals were X-rayed at birth. The lengths and widths of the humerus, radius, and femur and pelvic length, interischial, interpubic, and pubic widths were measured. Data were analyzed by ANOVA and LSD post hoc tests. The intersubject analysis showed significant differences between groups and non-significant differences between sexes. In males, sham-operated and RUB showed significant differences in pelvic lengths and widths, and humeral, radial, femoral, and tibial widths. In females, there were significant differences only for humeral widths, radial lengths and widths, and femoral and tibial widths. We conclude that reduced blood flow delays appendicular bone growth as observed at birth. Pelvic length was more affected than that of the limbs. The widths of the pelvic and limbs bones, in turn, were more altered than the lengths, and the growth of the males more than that of the females. Partial bending of uterine vessels compromised postcranial growth, though under such disadvantageous circumstances the females proved to be more capable of growing and thus more resilient than the males.

Estudio comparativo del estado nutricional de niños y niñas residentes en cuatro partidos de la provincia de Buenos Aires (Argentina), en el marco de la transición nutricional

The aim of this study was to evaluate and compare the nutritional status of child populations living in four counties of the province of Buenos Aires to observe differences related to particular environmental and socioeconomic contexts in the framework of the nutrition transition. During the school years corresponding to the 2008-2012 period, weight and height were measured and body mass index was calculated for 7,873 school children between the ages of 4 and 12 years from the counties of La Plata, Brandsen, Magdalena and Punta Indio. Information about the contexts of residence was obtained using self-administered structured surveys. About 40% of schoolchildren presented malnutrition, with a prevalence of overweight in La Plata, obesity in Punta Indio and undernutrition in Magdalena. The nutritional status of the study populations was associated with the socioenvironmental conditions of residence, indicating that these populations are at different stages of the nutrition transition process.