Marcela Castillo

Factores de riesgo para el desarrollo psicomotor en lactantes nacidos en óptimas condiciones biológicas

OBJETIVO: Avaliar o efeito dos fatores de risco para o desenvolvimento infantil em criancas de nivel socioeconomico baixo, nascidos em otimas condicoes biologicas, mas expostos a condicoes sociais adversas. METODOLOGIA: Lactentes dos dois sexos, no total de 788, foram exaustivamente estudados quanto a alimentacao, crescimento, ambiente fisico e psicossocial controladas. Controlaram-se prospectivamente ate os 12 meses de idade, momento em que se avaliou o desenvolvimento mental (MDI) e o motor (PDI) atraves da escala de Bayley. A partir das variaveis medidas, identificaram-se 18 fatores de risco, que foram dicotomizados (baixo e alto risco). RESULTADOS: Amamentacao materna, temperamento da crianca, inteligencia materna e estimulo no lar associam-se consistentemente com MDI e PDI. Apos ajuste por co-variaveis, o estimulo no lar persiste como fator significativo na explicacao da variabilidade do MDI e do PDI, e o sexo da crianca aparece-se como fator condicionante do desenvolvimento motor. O efeito acumulado de sete ou mais fatores de risco associa-se a uma diminuicao significativa das pontuacoes de desenvolvimento. A combinacao de categorias de risco de temperamento infantil, inteligencia materna, papel do pai e estimulo no lar, atinge melhor predicao do desenvolvimento infantil que outras combinacoes analisadas. CONCLUSAO: Conclui-se que, mesmo para as criancas em otimas condicoes biologicas, o desenvolvimento psicomotor e afetado na presenca de condicoes ambientais adversas que agem simultaneamente.

Iron-Fortified vs Low-Iron Infant Formula: Developmental Outcome at 10 Years

OBJECTIVE To assess long-term developmental outcome in children who received iron-fortified or low-iron formula. DESIGN Follow-up at 10 years of a randomized controlled trial (1991-1994) of 2 levels of formula iron. Examiners were masked to group assignment. SETTING Urban areas around Santiago, Chile. PARTICIPANTS The original study enrolled healthy, full-term infants in community clinics; 835 completed the trial. At 10 years, 473 were assessed (56.6%). INTERVENTION Iron-fortified (mean, 12.7 mg/L) or low-iron (mean, 2.3 mg/L) formula from 6 to 12 months. MAIN OUTCOME MEASURES We measured IQ, spatial memory, arithmetic achievement, visual-motor integration, visual perception, and motor functioning. We used covaried regression to compare iron-fortified and low-iron groups and considered hemoglobin level before randomization and sensitivity analyses to identify 6-month hemoglobin levels at which groups diverged in outcome. RESULTS Compared with the low-iron group, the iron-fortified group scored lower on every 10-year outcome (significant for spatial memory and visual-motor integration; suggestive for IQ, arithmetic achievement, visual perception, and motor coordination; 1.4-4.6 points lower; effect sizes, 0.13-0.21). Children with high 6-month hemoglobin levels (> 12.8 g/dL [to convert to grams per liter, multiply by 10]) showed poorer outcome on these measures if they received iron-fortified formula (10.7-19.3 points lower; large effect sizes, 0.85-1.36); those with low hemoglobin levels (< 10.5 g/dL) showed better outcome (2.6-4.5 points higher; small but significant effects, 0.22-0.36). High hemoglobin levels represented 5.5% of the sample (n = 26) and low hemoglobin levels represented 18.4% (n = 87). CONCLUSION Long-term development may be adversely affected in infants with high hemoglobin levels who receive 12.7 mg/L of iron-fortified formula. Optimal amounts of iron in infant formula warrant further study.

DOMESTIC VIOLENCE AND WOMEN'S MENTAL HEALTH IN CHILE

Domestic violence against women is a pervasive, global health problem. This study investigates the correlates and psychological outcomes of domestic abuse among women in a semi-industrial country. The participants included 215 mothers residing in working-class communities located on the outskirts of Santiago, Chile. We utilized structural equation modeling to test the hypothesis that poverty and other structural inequalities would be related to incidents of domestic abuse in Chile, as they are in the United States. Our results suggest that lower socioeconomic status, even within poor communities, and stressful life events have a direct relationship to domestic conflict. Domestic abuse was, in turn, associated with womens mental health such that greater domestic conflict was related to higher reports of depressive affect and symptoms of posttraumatic stress disorder. The importance of identifying similarities and differences in the occurrence of domestic violence in developing countries as compared to industrialized countries is discussed.

Iron Supplementation in Infancy Contributes to More Adaptive Behavior at 10 Years of Age

Most studies of behavioral/developmental effects of iron deficiency anemia (IDA) or iron supplementation in infancy have found social-emotional differences. Differences could relate to behavioral inhibition or lack of positive affect and altered response to reward. To determine long-term behavioral effects, the study was a follow-up of a randomized controlled trial of behavioral/developmental effects of preventing IDA in infancy. Healthy Chilean infants free of IDA at age 6 mo were randomly assigned to iron supplementation or no added iron (formula with iron/powdered cow milk, vitamins with/without iron) from ages 6 to 12 mo. At age 10 y, 59% (666 of 1123) and 68% (366 of 534) of iron-supplemented and no-added-iron groups were assessed. Social-emotional outcomes included maternal-reported behavior problems, self-reported behavior, examiner ratings, and video coding of a social stress task and gamelike paradigms. Examiners rated the iron-supplemented group as more cooperative, confident, persistent after failure, coordinated, and direct and reality-oriented in speech and working harder after praise compared with the no-added-iron group. In a task designed to elicit positive affect, supplemented children spent more time laughing and smiling together with their mothers and started smiling more quickly. In the social stress task they smiled and laughed more and needed less prompting to complete the task. All P values were <0.05; effect sizes were 0.14-0.36. There were no differences in behaviors related to behavioral inhibition, such as anxiety/depression or social problems. In sum, iron supplementation in infancy was associated with more adaptive behavior at age 10 y, especially in affect and response to reward, which may improve performance at school and work, mental health, and personal relationships.

Developmental Scores at 1 Year With Increasing Gestational Age, 37–41 Weeks

OBJECTIVE: To examine the relationship between gestational age and mental and psychomotor development scores in healthy infants born between 37 and 41 weeks. METHODS: The cohort included 1562 participants enrolled during infancy in an iron deficiency anemia preventive trial in Santiago, Chile. All participants were healthy, full-term (37–41 weeks) infants who weighed 3 kg or more at birth. Development at 12 months was assessed using the Bayley Scales of Infant Development. Using generalized linear modeling, we analyzed the association between gestational age and 1-year-old developmental status, taking into account potential confounders including birth weight percentile, gender, socioeconomic status, the home environment, iron status, and iron supplementation. RESULTS: For each additional week of gestation, the Mental Development Index increased by 0.8 points (95% confidence interval = 0.2–1.4), and the Psychomotor Development Index increased by 1.4 points (95% confidence interval = 0.6–2.1) controlling for birth weight percentile, gender, socioeconomic status, and home environment. CONCLUSIONS: In a large sample of healthy full-term infants, developmental scores obtained using the Bayley Scales of Infant Development at 12 months increased with gestational age (37–41 weeks). There is increasing evidence that birth at 39 to 41 weeks provides developmental advantages compared with birth at 37 to 38 weeks. Because cesarean deliveries and early-term inductions have increased to 40% of all births, consideration of ongoing brain development during the full-term period is an important medical and policy issue.

Adolescent Metabolic Syndrome Risk Is Increased with Higher Infancy Weight Gain and Decreased with Longer Breast Feeding

Background. Prevalence of the metabolic syndrome is increasing in pediatric age groups worldwide. Meeting the criteria for the metabolic syndrome puts children at risk for later cardiovascular and metabolic disease. Methods. Using linear regression, we examined the association between infant weight gain from birth to 3 months and risk for the metabolic syndrome among 16- to 17-year-old Chilean adolescents (n = 357), accounting for the extent of breastfeeding in infancy and known covariates including gender, birth weight, and socioeconomic status. Results. Participants were approximately half male (51%), born at 40 weeks of gestation weighing 3.5 kg, and 48% were exclusively breastfed for ≥90 days. Factors independently associated with increased risk of metabolic syndrome in adolescence were faster weight gain in the first 3 months of life (B = 0.16, P < 0.05) and male gender (B = 0.24, P < 0.05). Breastfeeding as the sole source of milk for ≥90 days was associated with significantly decreased risk of metabolic syndrome (B = −0.16). Conclusion. This study adds to current knowledge about early infant growth and breastfeeding and their long-term health effects.

Linear and Ponderal Growth Trajectories in Well-Nourished, Iron-Sufficient Infants Are Unimpaired by Iron Supplementation

Iron deficiency remains the most common nutritional deficiency worldwide and supplementation is recommended during periods of high risk, including infancy. However, questions have been raised about possible adverse effects of iron on growth in iron-sufficient (IS) infants and the advisability of across-the-board iron supplementation. This study examined whether short- or long-term growth was impaired in IS infants who received iron supplementation. From a longitudinal study of healthy, breast-fed, low- to middle-income Chilean infants randomly assigned to iron supplementation or usual nutrition at 6 or 12 mo, we retrospectively identified infants meeting criteria for iron sufficiency at the time of random assignment (n = 273). Using multilevel analysis, ponderal and linear growth were modeled before, during, and after iron supplementation up to 10 y in 3 comparisons: 1) iron supplementation compared with usual nutrition from 6 to 12 mo; 2) iron supplementation compared with usual nutrition from 12 to 18 mo; and 3) 15 mg/d of iron as drops compared with iron-fortified formula (12 mg/L). Growth trajectories did not differ during or after supplementation indicating no adverse effect of iron in any comparison. These results suggest that, at least in some environments, iron does not impair growth in IS infants.

Sexual intercourse among adolescents in Santiago, Chile: a study of individual and parenting factors

OBJECTIVE to examine a range of individual, parenting, and family factors associated with sexual intercourse among a community sample of youth and their families in Santiago, Chile. METHODS Data were taken from the Santiago Longitudinal Study conducted in January 2008-November 2009. Participants were 766 youth (mean age = 14.03 years, 51% male) from municipalities of low- to mid-socioeconomic status. Variables included emotional and behavioral subscales from the Child Behavior Checklists Youth Self Report, parental monitoring, family involvement, parental control and autonomy, relationship with each parent, and sexual activity. Bivariate and multivariate logistic regression models were used to examine the odds of sexual intercourse initiation. RESULTS seventy (9.14%) youth reported having had sex in their lifetime; the average age of first sexual intercourse among this group was 13.5 years (Standard Deviation [SD] = 1.74) for males and 14.08 (SD = 1.40) for females. Having sex was inversely associated with withdrawn-depressed symptoms (Odds Ratio [OR] = 0.84, Confidence Interval [CI] = 0.72-0.97), but positively associated with somatic complaints (OR = 1.20, CI = 1.04-1.38) and rule breaking behavior (OR = 1.21, CI = 1.08-1.36), after adjusting for demographic and other individual and parenting variables. The majority (80%) of the youth who had had sex reported using protection at the time of last intercourse. CONCLUSIONS findings highlight the role that mental health problems-some of them not commonly associated with onset of sexual activity-may play in a youths decision to have sex. The potential protective effects of several parenting and family characteristics disappeared with youth age and youth behavioral problems.

Higher Infant Blood Lead Levels with Longer Duration of Breastfeeding

OBJECTIVE To determine whether longer breastfeeding is associated with higher infant lead concentrations. STUDY DESIGN Data were analyzed from 3 studies of developmental effects of iron deficiency in infancy: Costa Rica (1981-1984), Chile (1991-1996), and Detroit (2002-2003). The relation between duration of breastfeeding and lead levels was assessed with Pearson product-moment or partial correlation coefficients. RESULTS More than 93% of the Costa Rica and Chile samples was breastfed (179 and 323 breastfed infants, respectively; mean weaning age, 8-10 months), as was 35.6% of the Detroit sample (53 breastfed infants; mean weaning age, 4.5 months). Lead concentrations averaged 10.8 microg/dL (Costa Rica, 12-23 months), 7.8 microg/dL (Chile, 12 months), and 2.5 microg/dL (Detroit, 9-10 months). Duration of breastfeeding as sole milk source and total breastfeeding correlated with lead concentration in all samples (r values = 0.14-0.57; P values = .06-<.0001). CONCLUSIONS Longer breastfeeding was associated with higher infant lead concentration in 3 countries, in 3 different decades, in settings differing in breastfeeding patterns, environmental lead sources, and infant lead levels. The results suggest that monitoring lead concentrations in breastfed infants be considered.

Satiety responsiveness and eating behavior among Chilean adolescents and the role of breastfeeding

Objective:To determine patterns of satiety responsiveness and its relationship to eating in the absence of hunger (EAH), in a cohort of adolescents. We also assessed whether sex, body mass index and duration of breastfeeding, during infancy, predicted satiety responsiveness and eating behavior at 16 years.Methods:Adolescents (n=576) from a longitudinal cohort, which began as an iron deficiency anemia preventive trial, participated in an unlimited breakfast after an overnight fast, and reported satiety response on a visual analog scale after the meal, followed by an EAH procedure. Height, weight and body composition were measured before breakfast. Latent profile analysis generated profiles that captured individual differences in satiety responsiveness. Multivariable regressions, adjusted for potential confounders, evaluated the association between: (1) satiety responsiveness and EAH, and (2) breastfeeding in infancy, satiety responsiveness and EAH in adolescence.Results:Participants were on average 16.7-year old, 48% female, 37% overweight/obese and 76% were breastfed as the sole source of milk for <6 months. We found three latent profiles of satiety responsiveness: 1: ‘responsive’ (49%); 2: ‘not responsive’ (41%); 3: ‘still hungry’ (10%). Participants in the ‘not responsive’ or ‘still hungry’ profile were more likely to eat during the EAH procedure (odds ratio (OR)=2.5, 95% confidence interval (CI)=1.8–3.6). Being breastfed for <6 months was related to higher odds of being in the ‘not responsive’ or ‘still hungry’ profile (OR=1.8, 95% CI=1.2–2.6) and EAH (OR=2.2, 95% CI=1.4–3.3). Satiety responsiveness was not influenced by sex and overweight/obesity.Conclusion:After an ad libitum meal, we found varied satiety responses, which related to EAH. Furthermore, shorter breastfeeding duration was associated with poorer satiety response and higher consumption during an EAH procedure. Understanding if breastfeeding influences the development of satiety responsiveness and eating behavior may be important in an era characterized by abundant calorie-dense foods and a plethora of environmental cues promoting consumption.