Birth weight, current body mass index, and insulin sensitivity and secretion in young adults in two Latin American populations.

BACKGROUND AND AIMS: Although studies have shown association of birth weight (BW) and adult body mass index (BMI) with insulin sensitivity in adults, there is limited evidence that BW is associated with insulin secretion. We assessed the associations between BW and current BMI with insulin sensitivity and secretion in young Latin American adults. METHODS AND RESULTS: Two birth cohorts, one from Ribeirao Preto, Brazil, based on 1984 participants aged 23-25 years, and another from Limache, Chile, based on 965 participants aged 22-28 years were studied. Weight and height at birth, and current fasting plasma glucose and insulin levels were measured. Insulin sensitivity (HOMA%S) and secretion (HOMA%ß) were estimated using the Homeostatic Model Assessment (HOMA2). Multiple linear regression analyses were carried out to test the associations between BW and adult BMI z-scores on log HOMA%S and log HOMA%ß. BW z-score was associated with HOMA%S in the two populations and HOMA%ß in Ribeirao Preto when adult BMI z-score was included in the model. BW z-score was associated with decreasing insulin secretion even without adjusting for adult BMI, but only in Ribeirao Preto. BMI z-score was associated with low HOMA%S and high HOMA%ß. No interactions between BW and BMI z-scores on insulin sensitivity were shown. CONCLUSIONS: This study supports the finding that BW may affect insulin sensitivity and secretion in young adults. The effect size of BW on insulin status is small in comparison to current BMI.

Secular trend in age at menarche in indigenous and nonindigenous women in Chile.

OBJECTIVES: To estimate the secular trend in age at menarche, comparing indigenous and nonindigenous women, and its relationship with socio-demographic, family and nutritional factors. METHODS: A study (historical cohorts) of 688 indigenous and nonindigenous women, divided into four birth cohorts (1960-69, 1970-79, 1980-89, and 1990-96) in an area in central southern Chile was carried out. Data and measurements were collected by health professionals using a previously validated questionnaire. Age at menarche was self-reported (recall). Adjusted differences among cohorts were estimated using a multivariate regression model. RESULTS: A secular trend (P < 0.001) in age at menarche was found in both ethnic groups, with no significant differences between them (P > 0.05). In an adjusted model, a reduction in age at menarche was estimated at 3.7 months per decade between 1960 and 1990. This trend was moderated by higher socio-economic level, smaller number of siblings, and cohabitation with a single parent during infancy. CONCLUSIONS: The trend has occurred in a steady progression over time in indigenous women, whereas in nonindigenous women, it was slow initially but has accelerated in recent years. Nonindigenous women have maintained a slightly lower age of menarche than their indigenous counterparts.

Relationship between oxidative stress-related biomarkers and antioxidant status with asthma and atopy in young adults: a population-based study.

BACKGROUND AND AIM: Enhanced oxidative stress has been described in adults who suffer from symptoms of asthma and poor lung function. This study assessed the relation between markers of oxidative stress and antioxidant status and lung function, symptoms of asthma, atopy and bronchial hyperresponsiveness (BHR) in young adults. METHODS: A sub-sample of 589 individuals aged 22-28 years, selected from a total of 1232 included in a survey assessing early and current risk factors for chronic diseases, participated in the study. Participants were from an agricultural area of Chile, responded to a Spanish version of the European Community Respiratory Health Survey questionnaire, were skin tested to eight allergens, and challenged with methacholine to assess BHR. Five hundred and eighty-five individuals had measures of plasma biomarkers ferric reducing ability of plasma, uric acid, protein carbonyls and 564 had 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) assessed. RESULTS: All participants had detectable plasma 8-iso-PGF(2alpha) and carbonyl levels. There was no indication for an association between markers of antioxidant status or oxidative stress with any of the outcomes studied. CONCLUSION: The levels of oxidative stress-related biomarkers and antioxidant status in plasma may not be related to asthma in the general population in the absence of more severe symptoms or exacerbations.

Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adults.

BACKGROUND: The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries. OBJECTIVE: To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings. METHODS: We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata. RESULTS: The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma. CONCLUSION: The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.

Nutritional status, especially body mass index, from birth to adulthood and lung function in young adulthood.

OBJECTIVE: The study assessed the impact of body mass index (BMI) at birth, infancy, and adulthood, and waist circumference on lung function. METHODS: Using a longitudinal design 1221 Chilean young adults were studied. A standardized respiratory questionnaire was used. Forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), height, weight and waist circumference were measured. Data at birth and at 1 year were obtained from clinical notes. RESULTS: Males with a BMI > or = 30 and women with a BMI < 20 had a lower FEV(1) (-230 mL, 95% CI -363 to -98; -106 mL, 95% CI -211 to -0.18, respectively). In both sexes those with a BMI 20-25 had the highest FEV(1) and FVC. In males there was a negative association between waist circumference and FEV(1) and FVC while in women the middle tertile had the highest FEV(1) and FVC. There was an association between birthweight and BMI at birth, and FEV(1) in men, when unadjusted for other measurements. CONCLUSIONS: BMI and waist circumference in adulthood make a greater impact on lung function in adulthood than anthropometric measurements at birth and infancy. Proxy measures of fatness in adulthood reduce lung function, but the pattern between fatness and lung function by sex may be different.

Respiratory consequences of light and moderate smoking in young adults in Chile.

OBJECTIVE: To assess the association between smoking and respiratory symptoms, lung function and bronchial hyperresponsiveness (BHR) in young adults in Chile. SETTING: Selected sample of 1232 subjects aged 22-28 years. DESIGN: In this cross-sectional study, the outcome measures were: respiratory symptoms, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% (FEF25-75), FEV1/FVC and BHR. RESULTS: Among the 1232 subjects, 67.7% of the men and 49.4% of the women were smokers; the median cigarettes smoked per day was four for men and three for women. Smoking was associated with wheezing, waking up with a cough, breathlessness following exercise and persistent cough, with odds ratios (OR) between 1.94 (95% CI 1.41-2.66) and 3.12 (95% CI 2.21-4.40) among those smoking > or = 5 cigarettes per day, compared to non-smokers. Smoking < 5 cigarettes was significantly associated with wheezing and waking up with a cough. Smokers had a lower FEV1/FVC than non-smokers by approximately 0.8%. Smoking was not associated with FEV1, FEF25-75 or BHR status. CONCLUSIONS: This study highlights the early effects of smoking on respiratory symptoms. It could help governments in Latin America take vigorous action to deter young people from starting smoking.

Prevalence of asthma, atopy and bronchial hyperresponsiveness and their interrelation in a semi-rural area of Chile.

OBJECTIVE: To assess the prevalence of asthma symptoms and their association with sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine. SETTING: A random sample of 1232 adults, aged 22 to 28 years, studied in a Chilean semi-rural area. DESIGN: A cross-sectional design for the purpose of this analysis. RESULTS: The prevalence of wheeze was 27.4% (95%CI 24.9-29.9) and waking with breathlessness 13.7% (95%CI 11.8-15.6), higher than the results of a multi-centre European study. Only 7.8% (95%CI 6.3-9.3) had a positive BHR (< or =8 mg/ml) and 26.3% (95%CI 23.8-28.8) were atopic. The Youden index of asthma symptoms in non-atopic subjects varied from 0.184 to 0.259 when using BHR as gold standard for asthma, and increased from 0.379 to 0.504 among those with positive atopy. Only 4.5% reported asthma, and the Youden index was slightly higher in comparison to the asthma symptom groups. CONCLUSION: The prevalence of asthma symptoms in young adults was high, but only a small proportion of these were sensitised or had a positive BHR. We believe that aetiological studies of asthma should analyse subjects with asthma symptoms separately from those with positive atopic status or positive BHR.

t-butyl-4-hydroxyanisole as an inhibitor of tumor cell respiration.

The effect of t-butyl-4-hydroxyanisole (BHA), a widely used food antioxidant additive, on the culture growth, oxygen consumption, and redox state of some electron carriers of intact TA3 and 786A ascites tumor cells has been studied. BHA inhibited culture growth and respiration of these two tumor cell lines, by inhibiting the electron flow through the respiratory chain. Experiments to determine its site of action showed that BHA did not inhibit noticeably the electron flow through cytochrome oxidase, due to the ability of N,N,N',N'-tetramethyl-p-phenylenediamine to bypass the BHA inhibition of the respiration. Electron flow through the ubiquinone-cytochrome b-c1 complex also was unaffected by BHA; in fact, BHA failed to inhibit the oxidation of duroquinol. Spectrophotometric experiments are in accordance with studies carried out using synthetic electron donors. The redox state of NAD(P)+, determined in steady-state conditions, changed to a more reduced level, and the redox states of ubiquinone, cytochrome b, cytochromes c + c1 and cytochromes a + a3 changed to a more oxidized level. These observations suggest that the electron transport in the tumor mitochondria was inhibited by BHA at the NADH-dehydrogenase-ubiquinone level (energy-conserving site 1). These findings could explain, in part, the cytotoxic effect of BHA.

[School feeding programmes in Latin America. An analysis]. / Programas de nutrición escolar en América Latina. Un análisis.

Governments in Latin American countries invest large amounts of resources in school feeding programmes, part of educational and social strategies to reach highly vulnerable group within the respective societies. We analysed the criteria used in selecting the beneficiaries of these programmes, the food distributed, management structures and lessons that have been learned from these processes. Differences found among development strategies in each country were also considered. At present, these strategies are centred on the efficient use of resources, focusing interventions on the neediest groups, and leaving aside the idea of universal benefits. In general, countries provide most types of food, such as breakfast lunch, snacks or just a glass of milk, free of charge. Recipients receive up to 1.000 calories and 30 g of selected protein per day. About execution; Latin American States have generally abandoned the integral management of these programmes, a former characteristic that included the purchasing of or production, reparation and delivery of specific food stuffs. Instead, the respective States have only maintained the organisational functions of planning and control of priority actions whilst the private sector has progressively taken an active part in developing strategies. Community participation is restricted to a minimum. We expect that this paper will be taken into consideration by those who bear the responsibility of formulating, executing and evaluating nutritional interventions directed at schoolchildren in selected Latin American regions.

[Programs and politics on growth deficit (consequences of a line of research carried out in Chile)]. / Programas y políticas referentes al déficit de crecimiento. (Repercusiones de una línea de investigación realizada en Chile).

This communication offers suggestions for programs and policies in relation to stunting within the infant population. The proposal is based on current social strategies and the results of research carried out on Chilean school children. These results indicate that height deficit is concentrated in sectors of the population belonging to low socio-economic levels, and the risk factors are related to the small stature of their parents with a record of undernutrition, small size at birth and low per capita income. This deficit begins early, occurring mainly before the child's second birthday and as a consequence is reflected in below average performance at school of those children living in areas of social vulnerability. Suggestions offered take into account the orientation that should be considered for social policies, the selection of beneficiaries, program contents and management and problems that need to be overcome. Among these, the following issues are highlighted:--That the social welfare programs designed to combat stunting in the infant population should have, as a priority objective, the aim of benefiting sectors of the population most at need. It is vital to include in these programs: adequate pre-natal care of women with a high risk profile of giving birth to a child with intrauterine growth retardation; promotion of child growth; food supplementation and/or fortification, and improvement of physical fitness.--The government should play a leading role in the promotion and management of these programs, in the regulation of private sector involvement, as well as promoting local community participation.--Warnings are given about the inadequacies of present government social welfare policies related to infant nutrition, and the lack of research carried out into the effectiveness of current programs. In relation to future aims, we would like to see more emphasis put into the integration of international and regional intervention programs aimed at combating infant undernutrition. This would include sharing resources and collecting information related to the problem. Finally, all these actions should be aligned and focused on the principal aim; allowing children to reach their full growth potential.

[Risk factors of short stature in Chilean school children from rural areas of high social vulnerability]. / Factores de riesgo de talla baja en escolares chilenos de zonas rurales de alta vulnerabilidad social.

Growth retardation, a prevalent problem in Chile, was studied in rural countries of high social vulnerability. Risk factors were identified with a paired case-control design. Domiciliary interviews of the parents of 161 pairs of children between 6-8 were conducted. Cases were children between -1 and -3z scores of height/age index and Controls were children between +/- 1/2z score. The higher significant relative risks analized with univariate methods (OR) were: large familiar group, limited domestic belongings, underweight during pregnancy, insufficient weight and height at birth, undernutrition and low stature of both parents. Conditional logistic regression model showed a high likelihood ratio of 98,20. The higher OR values were for father's stature (OR=4,98) mother's stature (OR=4,64), undernutrition (OR=4,53) and insufficient weight at birth (OR=3,23). These results indicate that small size in rural school age children of low socioeconomic level is determined by heredity, specially father's stature and adverse environmental factors, being undernutrition the main contribution. These results may became a significant subsidy to design [correction of desing] interventions to improve the nutritional status of children of low socioeconomic level. Thus contributing to develop all their physical growth potential.

[Risk factors for growth retardation in children of low economic and social level in São Paulo, Brazil]. / Fatores de risco ao retardo de crescimento estatural em crianças de baixo nível econômico e social de São Paulo, Brasil.

Aiming to analyze the mild to moderate growth retardation associate factors in children at school age, a case control study was conducted with 153 pairs of seven and eight years old children from public schools of the outskirts of the city. The cases were defined as children with a height for age(H/A) between -1 and -2 Z score, according to NCHS/WHO standards, and matched with a H/A +/- 0.5 Z-score children of same age, gender, school, classroom and class time, as controls. The height was measured at school according to WHO rules by trained professionals, and household visits were carried out to obtain environmental and socio-economic data. Initially the data was analyzed by the univariate conditional method and then, the statistically significant variables were included in a model of multivariate logistic regression analysis. As a result, the risk factors remaining at the end of the multivariate analyses, by Odds Ratio and it's 95% Confidence Interval were respectively:--mother's height: for each decrease of one standard deviation the OR increased 1.84(CI: 1.35 to 2.49); inadequate feeding pattern: OR = 2.12; CI: 1.17 to 3.83, very low socio-economic level: OR = 9.2; CI: 3.35 to 25.13, low birth weight: OR = 2.59; CI: 1.44 to 4.63 and smoking during pregnancy: OR = 1.75; CI: 0.98 to 3.12. These results highlight the environment as a determinant factor for growth performance during the first years of the child's life. Despite this, the significant OR for Mother's height allows the assumption that besides the environment, the parent's height has to be considered as one of the determinants of height deficit, even for the low socioeconomic level.

[Evolution of child undernutrition in Chile and some of its conditioning factors: a time series analysis]. / Evolución de la desnutrición infantil en Chile y algunos de sus factores condicionantes: un análisis de series temporales.

The objective of this study was to determine the evolution of the nutritional status of the population under five years of age during the period 1975-1990. Several conditioning factors were also assessed. The information was evaluated through time series analysis by using the AREG procedure. This procedure allows for the estimation of a regression model correcting by the autocorrelation of errors. Results indicates a significant trend to decreased undernutrition rates (p < 0.0001). A seasonal effect on undernutrition was observed, being higher the prevalences in summer. Analysis of selected conditioning factors, as well as the familiar buying capacity remained stable during the period. An exception to the lack of association among undernutrition and the conditioning factors evaluated, was seen during the period 1975-1982 when clear inverse relationship was evidenced. In conclusion, the decrease of infant undernutrition in Chile during the period 1975-1990 was not related to the changes observed in certain socioeconomic indices.

PIP: Changes in the nutritional status of the population under five years of age enrolled in Chile's National System of Health Services between 1975 and 1990 were studied, and their relationship to changes in the purchasing power of the population and to nutrition programs was assessed. A time series was constructed using quarterly data from 1975 to 1990 for the dependent and independent variables. The dependent variable was the nutritional status of children under five, assessed by weight for age from Ministry of Health records. The independent variables were income, purchasing power, cost of the basic food basket, and supplementary feeding programs. Various sources of official statistics were utilized in constructing the indicators. A multiple regression analysis was carried out for each series to determine the origin of variation. The procedure allowed for estimation of a regression model correcting by the autocorrelation of errors. A negative trend was observed in the total malnutrition rate for children under five, which was attributed to the decline between 1975 and 1982. After the first quarter of 1982 the trend stabilized at around 8 to 9%. The series also showed a pattern of seasonality, with the greatest prevalence of malnutrition in the first quarter corresponding to the summer. Purchasing power remained stable, especially in low income groups, and also presented seasonal trends, with purchasing power greatest in the summer months. Spending on nutrition programs did not present significant variation. It was concluded that a trend to decline of malnutrition occurred but was not related to the behavior of the other series studied except during 1975-82, when the socioeconomic indicators improved and malnutrition declined.

[Comparison between nutritional status of school children of low socioeconomic level from Santiago, Chile and Sao Paulo, Brazil]. / Comparacion de la situacion nutricional en escolares de bajo nivel socioeconomico de Santiago (Chile) y San Pablo (Brasil).

The objectives of this study were to determine and compare the anthropometric profiles of schoolchildren from low income household from Santiago, Chile and Sao Paulo, Brasil. A total of 1779 children from Santiago and 2210 from Sao Paulo were evaluated. Z-score distribution of the height/age (H/A), weight/age (W/A) and weight/height (W/H) indicators were utilized to assess the children. As a reference, the pattern recommended by WHO was used. The distribution of the H/A curves from both cities were deviated to the left. This deviation was more evident in Santiago. This situation points out the existence of a greater prevalence of growth retardation of the children from this city. In relation to the W/A indicator, both groups showed a similar distribution curves, Sao Paulo group however, had an increment of cases in the left extreme of the curve, under -2 <>. According to the W/H indicator the profile of both groups are different; one-Santiago-is deviated to the excess and Sao Paulo to the deficit. The differences observed in both groups of children studied indicated higher deficit of height, but lower current undernutrition in Santiago and increased wasting with conservated height in Sao Paulo. The observed situation suggests that the distinct patterns are consequences of socioeconomic factors at different stages of the growing process of the children and/or etnic differences of the population.

Is there a causal relation between obesity and asthma? Evidence from Chile.

OBJECTIVE: An association between obesity and asthma symptoms has been reported in the literature, but such a relationship is inconsistent if atopic status or bronchial hyper responsiveness (BHR) is considered. The objective was to assess the association between obesity and asthma symptoms or BHR in adults. METHODS: A study was carried out in 1232 people born between 1974 and 1978 in Chile. The participants completed the European Community Health Survey questionnaire, were skin tested and subject to a BHR challenge to methacholine. MEASUREMENTS: Weight, height and waist circumference were measured and body mass index (BMI) was calculated. RESULTS: There was a positive association between wheeze and breathlessness following exercise and BMI (both with an OR 1.03, 95% CI 1.00-1.06), the associations with wheeze tended to disappear in women who did react at least to one allergen, and persisted in those who did not react to any allergens. BMI was negatively associated with BHR (OR 0.93, 95% CI 0.89-0.97). Waist circumference was not associated with asthma symptoms and it was negatively associated with BHR. CONCLUSION: Although there was an association between BMI and asthma symptoms, there were weaknesses in the evidence because waist circumference, a more direct measure of obesity than BMI, was not associated with asthma symptoms, and BMI and waist circumference were negatively associated with BHR.

The early origins hypothesis with an emphasis on growth rate in the first year of life and asthma: a prospective study in Chile.

BACKGROUND: There is uncertainty about the impact of the programming hypothesis in terms of nutritional status at birth, rate of growth in the first year of life, length of gestation, breast feeding, and episodes of illness on asthma. An analysis was therefore carried out to test this hypothesis. METHODS: Data were collected on 1232 children born between 1974 and 1978 in a semi-rural area of Chile. Measurements at birth and growth in the first year of life were obtained from a birth registry and clinical notes. Information on asthma was collected using the European Community Respiratory Health Survey questionnaire. Sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine were determined. All other information was obtained using a questionnaire. Polytomous logistic analyses were carried out to explore the association of factors at birth and during the first year of life with asthma symptoms, atopy, and BHR. RESULTS: Weight and length gain in the first year were positively associated with wheeze (odds ratio (OR) 1.004, 95% CI 1.001 to 1.007 and OR 1.11, 95% CI 0.98 to 1.25, respectively). A higher body mass index (BMI) at birth was protective in subjects reporting both wheeze and waking with breathlessness (OR 0.54, 95% CI 0.35 to 0.84). Length rate in tertiles divided by length at birth in tertiles was related to asthma symptoms (OR 1.68, 95% CI 1.19 to 2.37). Most other assessments were not associated with asthma. CONCLUSION: These results show promising but inconclusive evidence that a rapid rate of growth in length, especially in newborn infants of low length, might be involved in the aetiology of asthma.

[Stature of Chilean parents and children of different ethnicity and social vulnerability]. / Estatura de padres e hijos chilenos de diferente etnia y vulnerabilidad social.

OBJECTIVE: To analyze and compare the heights of first-year school children and their parents, according to ethnic background and socioeconomic status. MATERIAL AND METHODS: This is a cross-sectional study of indigenous and non-indigenous school children and their parents, belonging to three levels of social vulnerability: very high (poverty), medium, and very low. An indigenous school child was defined as any child having all four parental surnames of Mapuche origin; non-indigenous were those having Hispanic parental surname. Height was compared using Z scores, using WHO nutritional change reference values. Statistical analysis consisted in comparing differences of mean heights between parents and their children. Differences were assessed using Scheffe's method. RESULTS: Improvement in socioeconomic conditions was associated with increasing mean parental height (p < 0.001), except for indigenous mothers, who showed no height increase. Fathers from highly impoverished counties were 4 cm shorter than those living in very low vulnerability areas; height differences reached 2 cm among mothers (p < 0.001). Indigenous school children showed a positive height gradient with improving socioeconomic conditions (p < 0.001). This was not observed among non-indigenous children. When comparing parental height with children's height, children had a better height/age ratio than their parents (p < 0.01). This was specially evident among indigenous school children, who had on average 1.4 Z scores more than their parents. CONCLUSIONS: The upward height gradient related to improved social conditions, and the better height/age ratio seen in children in comparison to their parents, regardless their ethnic background and level of social vulnerability, is encouraging and suggests that interventions directed to the poorest groups, including the indigenous population, must be carried out.

The risk approach in preschool children suffering malnutrition and intestinal parasitic infection in the city of São Paulo, Brazil.

The association between parasitic infection and malnutrition in preschool children in the city of São Paulo, was studied according to degree of malnutrition, age, and income. Associations were assessed by risk analysis. Higher risks of malnutrition were found in children above 24 months of age infected with Ascaris, Trichuris or with more than three different parasites. The presence of more than three parasites per child affected nutritional status independently of income level. It is suggested that more attention should be given to intensity and chronicity of intestinal parasitic infection.