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Background: Millions of children globally are at risk of not reaching their developmental potential because of early adversities. We hypothesised that responsive caregiving and learning opportunities, components of nurturing care, at pre-school ages might mitigate the effects of adversities., Methods: We analysed longitudinal birth cohort data from Brazil (1993 Pelotas Birth Cohort, n=632) and South Africa (Birth to Twenty Plus [Bt20+] Birth Cohort, n=1130) to assess whether responsive caregiving and learning opportunities at pre-school ages (2-4 years) modified associations between cumulative early adversities and adolescent human capital. The cumulative adversities score (range 0-9) included household wealth and crowding; mothers' schooling, height, age, and mental health; and children's birthweight, gestational age, and length at age 12 months. We extracted data on responsive caregiving and learning opportunities from the Early Childhood Home Observation for Measurement of the Environment inventory, assessed at age 4 years (1993 Pelotas cohort) and 2 years (Bt20+ cohort). We examined three human capital indicators: intelligence quotient (IQ) assessed at age 18 years (1993 Pelotas cohort) and 16 years (Bt20+ cohort); psychosocial adjustment assessed at age 15 years and 14 years, respectively; and height assessed at age 18 years and 16 years, respectively. We used linear models with interaction terms between cumulative adversities, and responsive caregiving and learning opportunities, to predict adolescent human capital., Findings: For each additional Z score of total cumulative adversity, adolescent IQ decreased by 5·89 (95% CI -7·29 to -4·50) points in the 1993 Pelotas cohort (p<0·0001) and 2·69 (-4·52 to -0·86) points in the Bt20+ cohort (p=0·0039). After adjusting for total cumulative adversities, adolescent IQ points increased by 5·47 (95% CI 4·20 to 6·74) with each additional Z score of learning opportunities and by 2·26 (0·93 to 3·59) with each additional Z score of responsive caregiving in the 1993 Pelotas cohort, but not in the Bt20+ cohort (0·86 [-0·12 to 1·83] and 0·65 [-0·32 to 1·61], respectively). Associations between early adversities and IQ were modified by learning opportunities in the 1993 Pelotas cohort (beta coefficient for interaction 1·74, 95% CI 0·43 to 3·04; p=0·0092) and by responsive caregiving in the Bt20+ cohort (2·24, 0·94 to 3·54; p=0·0075). High nurturing environment attenuated the negative effects of early cumulative adversities on IQ., Interpretation: Early nurturing home environments protect young children against effects of early adversities on adolescent IQ, with long-term positive associations on adolescent cognition in two middle-income countries., Funding: Bill & Melinda Gates Foundation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Early growth faltering accounts for one-third of child deaths, and adversely impacts the health and human capital of surviving children. Social as well as biological factors contribute to growth faltering, but their relative strength and interrelations in different contexts have not been fully described., Objective: The aim of this study was to use structural equation modelling to explore social and biological multidetermination of child height at age 2 y in longitudinal data from 4 birth cohort studies in low- and middle-income countries., Methods: We analyzed data from 13,824 participants in birth cohort studies in Brazil, India, the Philippines, and South Africa. We used exploratory structural equation models, with height-for-age at 24 mo as the outcome to derive factors, and path analysis to estimate relations among a wide set of social and biological variables common to the 4 sites., Results: The prevalence of stunting at 24 mo ranged from 14.0% in Brazil to 67.7% in the Philippines. Maternal height and birthweight were strongly predictive of height-for-age at 24 mo in all 4 sites (all P values <0.001). Three social-environmental factors, which we characterized as "child circumstances," "family socioeconomic status," and "community facilities," were identified in all sites. Each social-environmental factor was also strongly predictive of height-for-age at 24 mo (all P values <0.001), with some relations partly mediated through birthweight. The biological pathways accounted for 59% of the total explained variance and the social-environmental pathways accounted for 41%. The resulting path coefficients were broadly similar across the 4 sites., Conclusions: Early child growth faltering is determined by both biological and social factors. Maternal height, itself a marker of intergenerational deprivation, strongly influences child height at 2 y, including indirect effects through birthweight and social factors. However, concurrent social factors, many of which are modifiable, directly and indirectly contribute to child growth. This study highlights opportunities for interventions that address both biological and social determinants over the long and short term.

Objective: Associations between parental and offspring size at birth are well established, but the relative importance of parental growth at different ages as predictors of offspring birthweight is less certain. Here we model parental birthweight and postnatal conditional growth in specific age periods as predictors of offspring birthweight., Methods: We analyzed data from 3,392 adults participating in four prospective birth cohorts and 5,506 of their offspring., Results: There was no significant heterogeneity by study site or offspring sex. 1SD increase in maternal birthweight was associated with offspring birthweight increases of 102 g, 1SD in maternal length growth 0-2 year with 46 g, and 1SD in maternal height growth Mid-childhood (MC)-adulthood with 27 g. Maternal relative weight measures were associated with 24 g offspring birth weight increases (2 year- MC) and 49 g for MC-adulthood period but not with earlier relative weight 0-2 year. For fathers, birthweight, and linear/length growth from 0-2 year were associated with increases of 57 and 56 g in offspring birthweight, respectively but not thereafter., Conclusions: Maternal and paternal birthweight and growth from birth to 2 year each predict offspring birthweight. Maternal growth from MC-adulthood, relative weight from 2-MC and MC-adulthood also predict offspring birthweight. These findings suggest that shared genes and/or adequate nutrition during early life for both parents may confer benefits to the next generation, and highlight the importance of maternal height and weight prior to conception. The stronger matrilineal than patrilineal relationships with offspring birth weight are consistent with the hypothesis that improving the early growth conditions of young females can improve birth outcomes in the next generation., (© 2014 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.)

Background: Performance in intelligence tests tends to be higher among individuals breastfed as infants, but little is known about the association between breastfeeding and achieved schooling. We assessed the association of infant feeding with school achievement in five cohorts from low- and middle-income countries. Unlike high-income country settings where most previous studies come from, breastfeeding is not positively associated with socioeconomic position in our cohorts, thus reducing the likelihood of a spurious positive association., Methodology and Principal Findings: Participants included 10,082 young adults from five birth cohorts (Brazil, India, Guatemala, the Philippines, and South Africa). The exposures variables were whether the subject was ever breastfed, total duration of breastfeeding, and age at introduction of complementary foods. We adjusted the estimates for age at follow up, sex, maternal age, smoking during pregnancy, birthweight and socioeconomic position at birth. The key outcome was the highest grade achieved at school. In unadjusted analyses, the association between ever breastfeeding and schooling was positive in Brazil, inverse in the Philippines, and null in South Africa; in adjusted analyses, these associations were attenuated. In Brazil, schooling was highest among individuals breastfed for 3-12 months whereas in the Philippines duration of breastfeeding was inversely associated with schooling; and null associations were observed in South Africa and Guatemala. These associations were attenuated in adjusted models. Late introduction of solid foods was associated with lower schooling achievement in Brazil and South Africa., Conclusion: Measures of breastfeeding are not consistently related to schooling achievement in contemporary cohorts of young adults in lower and middle-income countries.

Objective: We examined associations of birth weight and weight gain in infancy and early childhood with type 2 diabetes (DM) risk in five cohorts from low- and middle-income countries., Research Design and Methods: Participants were 6,511 young adults from Brazil, Guatemala, India, the Philippines, and South Africa. Exposures were weight at birth, at 24 and 48 months, and adult weight, and conditional weight gain (CWG, deviation from expected weight gain) between these ages. Outcomes were adult fasting glucose, impaired fasting glucose or DM (IFG/DM), and insulin resistance homeostasis model assessment (IR-HOMA, three cohorts)., Results: Birth weight was inversely associated with adult glucose and risk of IFG/DM (odds ratio 0.91[95% CI 0.84-0.99] per SD). Weight at 24 and 48 months and CWG 0-24 and 24-48 months were unrelated to glucose and IFG/DM; however, CWG 48 months-adulthood was positively related to IFG/DM (1.32 [1.22-1.43] per SD). After adjusting for adult waist circumference, birth weight, weight at 24 and 48 months and CWG 0-24 months were inversely associated with glucose and IFG/DM. Birth weight was unrelated to IR-HOMA, whereas greater CWG at 0-24 and 24-48 months and 48 months-adulthood predicted higher IR-HOMA (all P < 0.001). After adjusting for adult waist circumference, birth weight was inversely related to IR-HOMA., Conclusions: Lower birth weight and accelerated weight gain after 48 months are risk factors for adult glucose intolerance. Accelerated weight gain between 0 and 24 months did not predict glucose intolerance but did predict higher insulin resistance.