Insulin-like growth factor I concentrations in infancy predict differential gains in body length and adiposity: the Cambridge Baby Growth Study

The Possible Role of Postnatal Biphasic Dysregulation of IGF-1 Tone in the Etiology of Idiopathic Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a pervasive condition of neurodevelopmental origin with an increasing burden on society. Idiopathic ASD is notorious for its heterogeneous behavioral manifestations, and despite substantial efforts, its etiopathology is still unclear. An increasing amount of data points to the causative role of critical developmental alterations in the first year of life, although the contribution of fetal, environmental, and genetic factors cannot be clearly distinguished. This review attempts to propose a narrative starting from neuropathological findings in ASD, involving insulin-like growth factor 1 (IGF-1) as a key modulator and demonstrates how the most consistent gestational risk factors of ASD-maternal insulin resistance and fetal growth insufficiency-converge at the perinatal dysregulation of offspring anabolism in the critical period of early development. A unifying hypothesis is derived, stating that the co-occurrence of these gestational conditions leads to postnatal biphasic dysregulation of IGF-1 tone in the offspring, leading first to insulin-dependent accelerated development, then to subsequent arrest of growth and brain maturation in ASD as an etiologic process. This hypothesis is tested for its explanation of various widely reported risk factors and observations of idiopathic ASD, including early postnatal growth abnormalities, the pervasive spectrum of symptoms, familial predisposition, and male susceptibility. Finally, further directions of research are outlined.

Maternal protein intake during pregnancy and obesity risk in mothers and offspring: a prospective cohort study

BACKGROUND

The optimal dietary macronutrient composition during pregnancy to mitigate obesity risk in mothers and offspring remains unclear.

OBJECTIVES

This study aims to assess associations between maternal dietary macronutrient composition and obesity outcomes in mothers and offspring.

METHODS

We analyzed 66,360 singleton pregnancies from the Danish National Birth Cohort, with dietary intake assessed at gestational week 25. Outcomes included maternal postpartum weight retention (PPWR) at 6 and 18 mo and offspring's birth weight, risks of small for gestational age (SGA) and large for gestational age (LGA), body mass index (BMI) z-scores, and overweight/obesity (OWOB) risk at ages 7, 11, and 14 y. Mixture models with response surface visualization examined interactive macronutrient associations, and mixed restricted cubic splines assessed potential nonlinear relationships between maternal protein intake and obesity outcomes.

RESULTS

Mean maternal macronutrient compositions were 15.2% protein, 30.2% fat, and 54.1% carbohydrate. Response surfaces revealed that maternal lower protein intake (%), diluted by higher fat and/or carbohydrate, was associated with higher maternal PPWR at 6 and 18 mo but lower birth weight and BMI z-scores in offspring at ages 7, 11, and 14 y. Mixed restricted cubic splines indicated nonlinear associations between maternal protein intake (%) and SGA risk (nonlinear P = 0.003) and LGA (nonlinear P = 0.04), with a threshold around 15% protein; below this, SGA risk increased whereas LGA risk decreased. Linear associations were observed for risks of substantial PPWR (PPWR >5 kg) and childhood OWOB risk (nonlinear P > 0.05). Each 5% higher protein intake during pregnancy was related to a lower risk of substantial PPWR at 6 mo (odds ratio: 0.90; 95% confidence interval: 0.85, 0.95) and 18 mo (0.88; 0.82, 0.94) but higher risks of OWOB at ages 7 y (1.07; 1.01, 1.15) and 11 y (1.11; 1.03, 1.18), with no association at 14 y (1.02; 0.95, 1.10).

CONCLUSIONS

Higher maternal protein intake during pregnancy was associated with lower PPWR and SGA risk but higher LGA and childhood OWOB risks, highlighting potential trade-offs in maternal and offspring obesity outcomes.

Low-Protein Infant Formula Enriched with Alpha-Lactalbumin during Early Infancy May Reduce Insulin Resistance at 12 Months: A Follow-Up of a Randomized Controlled Trial

High protein intake during infancy results in accelerated early weight gain and potentially later obesity. The aim of this follow-up study at 12 months was to evaluate if modified low-protein formulas fed during early infancy have long-term effects on growth and metabolism. In a double-blinded RCT, the ALFoNS study, 245 healthy-term infants received low-protein formulas with either alpha-lactalbumin-enriched whey (α-lac-EW; 1.75 g protein/100 kcal), casein glycomacropeptide-reduced whey (CGMP-RW; 1.76 g protein/100 kcal), or standard infant formula (SF; 2.2 g protein/100 kcal) between 2 and 6 months of age. Breastfed (BF) infants served as a reference. At 12 months, anthropometrics and dietary intake were assessed, and serum was analyzed for insulin, C-peptide, and insulin-like growth factor 1 (IGF-1). Weight gain between 6 and 12 months and BMI at 12 months were higher in the SF than in the BF infants (p = 0.019; p < 0.001, respectively), but were not significantly different between the low-protein formula groups and the BF group. S-insulin and C-peptide were higher in the SF than in the BF group (p < 0.001; p = 0.003, respectively), but more alike in the low-protein formula groups and the BF group. Serum IGF-1 at 12 months was similar in all study groups. Conclusion: Feeding modified low-protein formula during early infancy seems to reduce insulin resistance, resulting in more similar growth, serum insulin, and C-peptide concentrations to BF infants at 6-months post intervention. Feeding modified low-protein formula during early infancy results in more similar growth, serum insulin, and C-peptide concentrations to BF infants 6-months post intervention, probably due to reduced insulin resistance in the low-protein groups.

Approach to the Patient: Case Studies in Pediatric Growth Hormone Deficiency and Their Management

CONTEXT

Pathologies attributed to perturbations of the GH/IGF-I axis are among the most common referrals received by pediatric endocrinologists.

AIM

In this article, distinctive cased-based presentations are used to provide a practical and pragmatic approach to the management of pediatric growth hormone deficiency (GHD).

CASES

We present 4 case vignettes based on actual patients that illustrate (1) congenital GHD, (2) childhood GHD presenting as failure to thrive, (3) childhood GHD presenting in adolescence as growth deceleration, and (4) childhood-onset GHD manifesting as metabolic complications in adolescence. We review patient presentation and a management approach that aims to highlight diagnostic considerations for treatment based on current clinical guidelines, with mention of new therapeutic and diagnostic modalities being used in the field.

CONCLUSION

Pediatric GHD is diverse in etiology and clinical presentation. Timely management has the potential not only to improve growth but can also ameliorate or even mitigate adverse metabolic outcomes, which can be directly attributed to a GH deficient state.

Leptin and IGF-1 in Infancy Are Associated With Variants in DHCR7 and CYP2R1 That Relate With Type 1 Diabetes and 25OHD

CONTEXT

Vitamin D has been variably implicated in risk of developing type 1 diabetes based on cohorts of at-risk individuals. Emergent type 1 diabetes in childhood is putatively preceded by altered growth.

OBJECTIVE

We explored whether polymorphisms in vitamin D metabolism genes modify risk of type 1 diabetes via effects on growth in a prospective, population-based cohort of infants.

METHODS

The Cambridge Baby Growth Study enrolled newborns from Cambridgeshire, UK, for follow-up in infancy. In 612 infants, we genotyped single nucleotide polymorphisms in vitamin D metabolism genes that relate with type 1 diabetes: rs10741657 and rs12794714 in CYP2R1, rs12785878 in DHCR7, and rs10877012 in CYP27B1. Multivariate linear regression analyses tested associations between genotypes and anthropometric indices (weight, length, and skinfold thickness) or growth-related hormones (C-peptide, IGF-1, and leptin) in infancy.

RESULTS

Birth weight showed borderline associations with the diabetes risk-increasing alleles in CYP2R1, rs10741657 (β = -.11, P = .02) and rs12794714 (β = -.09, P = .04). The risk-increasing allele rs12794714 was also associated with higher IGF-1 levels at age 24 months (β = .30, P = .01). At age 3 months, the risk-increasing allele rs12785878 in DHCR7, known to negatively associate with 25-hydroxyvitamin D levels, showed a positive association with leptin levels (β = .23, P = .009), which was pronounced in girls (P = .004) vs boys (P = .7).

CONCLUSION

The vitamin D metabolism genes DHCR7 and CYP2R1 might influence infancy leptin and IGF-1 levels respectively. These findings open the possibility for a developmental role of vitamin D that is mediated by growth-related hormones with implications for the onset of type 1 diabetes autoimmunity.

Investigation of Igf-1, Igf-Bp3 and Igf-Bp5 levels in umbilical cord blood of infants with developmental dysplasia of the hip

BACKGROUND

IGF-1 (insulin-like growth factor-1) is an important regulator of bone formation. Its deficiency has been associated with fetal growth disorders and hip dysplasia. The aim of this study was to evaluate whether IGF-1, IGF-BP3 (insulin like growth factorbinding protein 3), and IGF-BP5 levels in the umbilical cord blood can be predictive for early diagnosis of DDH.

METHODS

Umbilical cord blood samples were collected from 860 mothers with pregnancies at high risk for DDH between October 2020 and January 2021. Mothers at 37-42 weeks of gestation, with risk factors for DDH, who delivered healthy infants were included. Blood samples were collected during delivery. Each eligible infant was medically followed up and underwent a hip ultrasound in the postnatal 2nd or 3rd month. Infants diagnosed with DDH were matched with a healthy cohort in terms of sex, birth weight, maternal age, and gestational week, and the IGF-1, IGF-BP3 and IGF-BP5 levels were studied and compared.

RESULTS

Evaluation was made of 20 infants diagnosed with DDH and 60 healthy infants. Of the total 80 infants, 72.5% were female.The umbilical cord blood levels of IGF-1 and IGF-BP3 were similar in both groups. The IGF-BP5 values were significantly lower in the DDH patient group. Except for DDH diagnosis, the other categorical variables of the study did not appear to influence the levels of any of the IGFs.

DISCUSSION

Umbilical blood samples could potentially help diagnose DDH. The levels of IGF-BP5 were shown to be significantly lower in infants with DDH.

Infant Feeding Choices during the First Post-Natal Months and Anthropometry at Age Seven Years: Follow-Up of a Randomized Clinical Trial

The Belgrade–Munich Infant Milk Trial (BeMIM) randomized healthy term infants into either a protein-reduced intervention infant formula (IF) group, with an α-lactalbumin-enriched whey and long-chain polyunsaturated fatty acids, or a control infant formula (CF) group. A non-randomized breastfed group (BF) was studied for reference. We assessed the long-term effects of these infant feeding choices on growth measures until the age of seven years. Weight, standing height, head circumference, and percent body fat (using skinfolds and bioelectrical impedance) were determined with standardized methods. A total of 161 children out of the 256 completers of the initial study (63%) participated in the seven-year follow-up. Children in the three study groups did not differ in their anthropometric measures, including body mass index (IF 16.1 ± 2.6, CF: 15.6 ± 1.7, BF: 15.6 ± 2.5 kg/m², mean ± SD). IGF-1 serum concentrations determined at the age of 4 months contributed to explaining the variances in weight (p = 0.001), height (p = 0.001) and BMI (p = 0.035) z-scores at the age of seven years, whereas insulin levels at four months did not. Different feeding choices during the first four months of life leading to higher energy efficiency and increased growth with IF did not affect later growth outcomes at an early school age. Diet-induced modulation of IGF-1 in the first months of life may have lasting programming effects on later growth.

Correction of neonatal vitamin D status using 1000 IU vitamin D/d increased lean body mass by 12 months of age compared with 400 IU/d: a randomized controlled trial

BACKGROUND

Intrauterine exposure to maternal vitamin D status <50 nmol/L of serum 25-hydroxyvitamin D [25(OH)D] may adversely affect infant body composition. Whether postnatal interventions can reprogram for a leaner body phenotype is unknown.

OBJECTIVES

The primary objective was to test whether 1000 IU/d of supplemental vitamin D (compared with 400 IU/d) improves lean mass in infants born with serum 25(OH)D <50 nmol/L.

METHODS

Healthy, term, breastfed infants (Montréal, Canada, March 2016-2019) were assessed for serum 25(OH)D (immunoassay) 24-36 h postpartum. Infants with serum 25(OH)D <50nmol/L at 24-36 h were eligible for the trial and randomly assigned at baseline (1 mo postpartum) to 400 (29 males, 20 females) or 1000 IU/d (29 males, 20 females) of vitamin D until 12 mo. Infants (23 males, 18 females) with 25(OH)D ≥50 nmol/L (sufficient) formed a nonrandomized reference group provided 400 IU/d. Anthropometry, body composition (DXA), and serum 25(OH)D concentrations were measured at 1, 3, 6, and 12 mo.

RESULTS

At baseline, mean ± SD serum 25(OH)D concentrations in infants allocated to the 400 and 1000 IU/d vitamin D groups were 45.8 ± 14.1 and 47.6 ± 13.4, respectively; for the reference group it was 69.2 ± 16.4 nmol/L. Serum 25(OH)D concentration increased on average to ≥50 nmol/L in the trial groups at 3-12 mo. Lean mass varied differently between groups over time; at 12 mo it was higher in the 1000 IU/d vitamin D group than in the 400 IU/d group (mean ± SD: 7013 ± 904.6 compared with 6690.4 ± 1121.7 g, P = 0.0428), but not the reference group (mean ± SD: 6715.1 ± 784.6 g, P = 0.19). Whole-body fat mass was not different between the groups over time.

CONCLUSIONS

Vitamin D supplementation (400 or 1000 IU/d) during infancy readily corrects vitamin D status, whereas 1000 IU/d modestly increases lean mass by 12 mo. The long-term implications require further research. This trial was registered at clinicaltrials.gov as NCT02563015.

Dynamic Changes in Serum IGF-I and Growth During Infancy: Associations to Body Fat, Target Height, and PAPPA2 Genotype

CONTEXT

IGF-I is important for postnatal growth and may be of diagnostic value in infants suspected of pituitary disease; however, little is known about the impact of IGF-I and its determinants on infant growth. Importantly, detailed reference ranges for IGF-I and IGF binding protein-3 (IGFBP-3) concentrations during infancy are lacking.

OBJECTIVE

To evaluate the rapid changes in weight and length as well as their determinants in healthy infants, and to establish age- and sex-specific reference curves for IGF-I and IGFBP-3 in children aged 0 to 1 years.

DESIGN

Prospective longitudinal study.

SETTING

Cohort study.

PARTICIPANTS

A total of 233 healthy children (114 girls) with repeated blood samples during the first year of life.

MAIN OUTCOME MEASURE(S)

Serum concentrations of IGF-I and IGFBP-3, length velocity, weight velocity, and PAPPA2 (rs1325598) genotype.

RESULTS

Individual trajectories of length and weight velocities were sex specific. We provide detailed reference curves based on longitudinal data for IGF-I and IGFBP-3 during infancy. In both girls and boys, IGF-I decreased during infancy, whereas IGFBP-3 remained stable. IGF-I and IGFBP-3, but not PAPPA2 genotype, were positively associated with weight gain, but not with longitudinal growth. When stratified by sex, the association between weight gain and IGF-I only remained significant in girls.

CONCLUSIONS

Interestingly, we found a significant association between IGF-I and infant weight gain in girls, but not with longitudinal growth in the first year of life. Our findings highlight the role of IGF-I as an important anabolic hormone that is not limited to linear growth.

Correlates of serum IGF-1 in young children with moderate acute malnutrition: a cross-sectional study in Burkina Faso

BACKGROUND

Serum insulin-like growth factor 1 (sIGF-1) is an important growth factor in childhood. However, studies on sIGF-1 among children from low-income countries are few, and the role of body composition is unknown.

OBJECTIVES

To assess the associations of anthropometry, body composition, inflammation, and breastfeeding with sIGF-1 among children with moderate acute malnutrition (MAM).

METHODS

A cross-sectional study based on admission data from 6- to 23-mo-old children with MAM participating in a nutrition intervention trial (Treatfood) in Burkina Faso. Linear regression analysis was used to identify correlates of sIGF-1.

RESULTS

Among 1546 children, the median (IQR) sIGF-1 was 12 (8.2-18.3) ng/mL. sIGF-1 was highest at 6 mo, with a nadir ∼10-11 mo, and higher in girls than boys. Length-for-age z score (LAZ), weight-for-length z score (WLZ), and midupper arm circumference were positively associated with sIGF-1 (P ≤ 0.001). Fat-free mass (FFM) was also positively associated, as sIGF-1 increased 1.5 (95% CI: 0.5, 2.5) ng/mL for each 1-kg increase in FFM. However, the association disappeared after adjustment for height. Elevated serum C-reactive protein and α1-acid glycoprotein were negatively associated with sIGF-1 (P ≤ 0.001), as was fever (P < 0.001) but not a positive malaria test per se (P = 0.15). Children never breastfed had lower sIGF-1 (-5.1; 95% CI: -9.8, -0.3).

CONCLUSIONS

LAZ and WLZ were positively and inflammation negatively associated with sIGF-1. As all children were moderately malnourished and many had inflammation, this probably explains the very low median sIGF-1. The association of FFM with sIGF-1 was fully explained by height. There was a marked age pattern, with a nadir in late infancy, confirming findings from smaller studies from well-nourished populations. There is a need for prospective studies to disentangle the role of sIGF-1 in growth and health. This trial was registered at https://www.isrctn.com as ISRCTN42569496.

The High-Risk Type 1 Diabetes HLA-DR and HLA-DQ Polymorphisms Are Differentially Associated With Growth and IGF-I Levels in Infancy: The Cambridge Baby Growth Study

OBJECTIVE

This study explored the link between HLA polymorphisms that predispose to type 1 diabetes and birth size, infancy growth, and/or circulating IGF-I in a general population-based birth cohort.

RESEARCH DESIGN AND METHODS

The Cambridge Baby Growth Study is a prospective observational birth cohort study that recruited 2,229 newborns for follow-up in infancy. Of these, 612 children had DNA available for genotyping single nucleotide polymorphisms in the HLA region that capture the highest risk of type 1 diabetes: rs17426593 for DR4, rs2187668 for DR3, and rs7454108 for DQ8. Multivariate linear regression models at critical ages (cross-sectional) and mixed-effects models (longitudinal) were performed under additive genetic effects to test for associations between HLA polymorphisms and infancy weight, length, skinfold thickness (indicator of adiposity), and concentrations of IGF-I and IGF-binding protein-3 (IGFBP-3).

RESULTS

In longitudinal models, the minor allele of rs2187668 tagging DR3 was associated with faster linear growth (P = 0.007), which was more pronounced in boys (P = 3 × 10^-7) than girls (P = 0.07), and was also associated with increasing IGF-I (P = 0.002) and IGFBP-3 (P = 0.003) concentrations in infancy. Cross-sectionally, the minor alleles of rs7454108 tagging DQ8 and rs17426593 tagging DR4 were associated with lower IGF-I concentrations at age 12 months (P = 0.003) and greater skinfold thickness at age 24 months (P = 0.003), respectively.

CONCLUSIONS

The variable associations of DR4, DR3, and DQ8 alleles with growth measures and IGF-I levels in infants from the general population could explain the heterogeneous growth trajectories observed in genetically at-risk cohorts. These findings could suggest distinct mechanisms involving endocrine pathways related to the HLA-conferred type 1 diabetes risk.

Interactions between Growth of Muscle and Stature: Mechanisms Involved and Their Nutritional Sensitivity to Dietary Protein: The Protein-Stat Revisited

Childhood growth and its sensitivity to dietary protein is reviewed within a Protein-Stat model of growth regulation. The coordination of growth of muscle and stature is a combination of genetic programming, and of two-way mechanical interactions involving the mechanotransduction of muscle growth through stretching by bone length growth, the core Protein-Stat feature, and the strengthening of bone through muscle contraction via the mechanostat. Thus, growth in bone length is the initiating event and this is always observed. Endocrine and cellular mechanisms of growth in stature are reviewed in terms of the growth hormone-insulin like growth factor-1 (GH-IGF-1) and thyroid axes and the sex hormones, which together mediate endochondral ossification in the growth plate and bone lengthening. Cellular mechanisms of muscle growth during development are then reviewed identifying (a) the difficulties posed by the need to maintain its ultrastructure during myofibre hypertrophy within the extracellular matrix and the concept of muscle as concentric "bags" allowing growth to be conceived as bag enlargement and filling, (b) the cellular and molecular mechanisms involved in the mechanotransduction of satellite and mesenchymal stromal cells, to enable both connective tissue remodelling and provision of new myonuclei to aid myofibre hypertrophy and (c) the implications of myofibre hypertrophy for protein turnover within the myonuclear domain. Experimental data from rodent and avian animal models illustrate likely changes in DNA domain size and protein turnover during developmental and stretch-induced muscle growth and between different muscle fibre types. Growth of muscle in male rats during adulthood suggests that "bag enlargement" is achieved mainly through the action of mesenchymal stromal cells. Current understanding of the nutritional regulation of protein deposition in muscle, deriving from experimental studies in animals and human adults, is reviewed, identifying regulation by amino acids, insulin and myofibre volume changes acting to increase both ribosomal capacity and efficiency of muscle protein synthesis via the mechanistic target of rapamycin complex 1 (mTORC1) and the phenomenon of a "bag-full" inhibitory signal has been identified in human skeletal muscle. The final section deals with the nutritional sensitivity of growth of muscle and stature to dietary protein in children. Growth in length/height as a function of dietary protein intake is described in the context of the breastfed child as the normative growth model, and the "Early Protein Hypothesis" linking high protein intakes in infancy to later adiposity. The extensive paediatric studies on serum IGF-1 and child growth are reviewed but their clinical relevance is of limited value for understanding growth regulation; a role in energy metabolism and homeostasis, acting with insulin to mediate adiposity, is probably more important. Information on the influence of dietary protein on muscle mass per se as opposed to lean body mass is limited but suggests that increased protein intake in children is unable to promote muscle growth in excess of that linked to genotypic growth in length/height. One possible exception is milk protein intake, which cohort and cross-cultural studies suggest can increase height and associated muscle growth, although such effects have yet to be demonstrated by randomised controlled trials.

Associations of protein intake in early childhood with body composition, height, and insulin-like growth factor I in mid-childhood and early adolescence

BACKGROUND

Early protein intake may program later body composition and height growth, perhaps mediated by insulin-like growth factor I (IGF-I). In infancy, higher protein intake is consistently associated with higher IGF-I concentrations and more rapid growth, but associations of protein intake after infancy with later growth and IGF-I are less clear.

OBJECTIVES

Our objective was to examine associations of protein intake in early childhood (median 3.2 y) with height, IGF-I, and measures of adiposity and lean mass in mid-childhood (median 7.7 y) and early adolescence (median 13.0 y), and with changes in these outcomes over time. We hypothesized that early childhood protein intake programs later growth.

METHODS

We studied 1165 children in the Boston-area Project Viva cohort. Mothers reported children's diet using food-frequency questionnaires. We stratified by child sex and examined associations of early childhood protein intake with mid-childhood and early adolescent BMI z score, skinfold thicknesses, dual-energy X-ray absorptiometry (DXA) fat mass, DXA lean mass, height z score, and IGF-I concentration. We adjusted linear regression models for race/ethnicity, family sociodemographics, parental and birth anthropometrics, breastfeeding status, physical activity, and fast food intake.

RESULTS

Mean protein intake in early childhood was 58.3 g/d. There were no associations of protein intake in early childhood with any of the mid-childhood outcomes. Among boys, however, each 10-g increase in early childhood total protein intake was associated with several markers of early adolescent size, namely BMI z score (0.12 higher; 95% CI: 0.01, 0.23), DXA lean mass index (1.34% higher; 95% CI: -0.07%, 2.78%), and circulating IGF-I (5.67% higher; 95% CI: 0.30%, 11.3%). There were no associations with fat mass and no associations with any adolescent outcomes among girls.

CONCLUSIONS

Early childhood protein intake may contribute to programming lean mass and IGF-I around the time of puberty in boys, but not to adiposity development. This study was registered at clinicaltrials.gov as NCT02820402.

Patterns of Infancy Growth and Metabolic Hormonal Profile Are Different in Very-Low-Birth-Weight Preterm Infants Born Small for Gestational Age Compared to Those Born Appropriate for Gestational Age

BACKGROUND/AIMS

An increased preterm birth survival rate is associated with long-term neurological and metabolic risks; thus, our aim was to evaluate whether early patterns of infancy anthropometry and metabolic hormonal profile differ in preterm infants born small for gestational age (SGA) or appropriate for gestational age (AGA) from birth to 36 months of corrected age (CA).

METHODS

We recruited 110 very-low-birth-weight (VLBW) preterm infants (AGA = 60 and SGA = 50) with a mean birth weight of -2.39 ± 0.77 versus 0.57 ± 0.54 standard deviation scores (SDS) (p < 0.01) and birth length of -2.1 ± 1.05 versus -0.44 ± 0.82 SDS (p < 0.01), respectively. Anthropometry and blood sampling for insulin, insulin-like growth factor (IGF)-II, IGF-I, and leptin were performed for up to 3 years.

RESULTS

All neonates increased their weight, length, and head circumference SDS during the early inpatient period. Up to 90% reached a normal length within this period. The IGF-II, insulin, and glycemia concentrations changed in parallel with weight. In the first year of CA, only SGA infants gained weight and height SDS. The homoeostatic model assessment had a trend toward higher values in SGA infants at 24 and 36 months (p = 0.06 and p = 0.07).

CONCLUSION

Being SGA is the strongest predictor of early recovery of height in VLBW preterm infants. Follow-up will allow us to determine whether the differences in the growth patterns of VLBW preterm infants by birth weight SDS persist.

IGF-I and IGFBP-3 concentrations at 2 years: associations with anthropometry and milk consumption in an Indian cohort

BACKGROUND/OBJECTIVES

To ascertain associations between plasma insulin-like growth factor I (IGF-I), insulin-like growth factor-binding protein 3 (IGFBP-3) and their molar ratio at 2 y with neonatal size, infant growth, body composition at 2 y, and feeding practices in an Indian cohort.

SUBJECTS/METHODS

A cohort of 209 newborns, with 122 followed at 2 y. Anthropometry was conducted at birth and 2 y. IGF-I and IGFBP-3 concentrations were measured in cord blood and at 2 y. Maternal and child diet was assessed by food frequency questionnaires and maternal interviews. Multivariate regression was used to test for associations adjusting for confounding factors.

RESULTS

Mean 2 y plasma IGF-I and IGFBP-3 concentrations and IGF-I/IGFBP-3 were 49.4 ng/ml (95% CI: 44.1, 54.8), 1953.8 ng/ml (CI: 1870.6, 2036.9) ng/ml, and 0.088 (CI: 0.081, 0.095), respectively. IGF-I and IGF-I/IGFBP-3 were positively associated with current length, but not body mass index or adiposity. IGF-I was higher among those with greater change in length since birth. IGF-I concentrations were higher in children who drank the most milk (>500 vs. <250 ml per day: 65.6 vs. 42.8 ng/ml, p < 0.04), received other milk <6 months compared to ≥6 months (56.3 vs. 44.8 ng/ml, p < 0.05), and in those whose mothers consumed milk daily vs. less frequently in late pregnancy (56.4 vs. 42.7 ng/ml, p < 0.01). In multivariate regression, 2 y IGF-I concentration and IGF-I/IGFBP-3 were each positively associated with current length and milk intake. IGFBP-3 was not related to anthropometry or milk intake.

CONCLUSIONS

Plasma IGF-I concentrations and IGF-I/IGFBP-3 at 2 y are positively associated with length at 2 y and current milk intake.

Life History theory hypotheses on child growth: Potential implications for short and long-term child growth, development and health

Life history theory integrates ecological, physiological, and molecular layers within an evolutionary framework to understand organisms' strategies to optimize survival and reproduction. Two life history hypotheses and their implications for child growth, development, and health (illustrated in the South African context) are reviewed here. One hypothesis suggests that there is an energy trade-off between linear growth and brain growth. Undernutrition in infancy and childhood may trigger adaptive physiological mechanisms prioritizing the brain at the expense of body growth. Another hypothesis is that the period from conception to infancy is a critical window of developmental plasticity of linear growth, the duration of which may vary between and within populations. The transition from infancy to childhood may mark the end of a critical window of opportunity for improving child growth. Both hypotheses emphasize the developmental plasticity of linear growth and the potential determinants of growth variability (including the role of parent-offspring conflict in maternal resources allocation). Implications of these hypotheses in populations with high burdens of undernutrition and infections are discussed. In South Africa, HIV/AIDS during pregnancy (associated with adverse birth outcomes, short duration of breastfeeding, and social consequences) may lead to a shortened window of developmental plasticity of growth. Furthermore, undernutrition and infectious diseases in children living in South Africa, a country undergoing a rapid nutrition transition, may have adverse consequences on individuals' cognitive abilities and risks of cardio-metabolic diseases. Studies are needed to identify physiological mechanisms underlying energy allocation between biological functions and their potential impacts on health.

Effect of human milk formula with bovine colostrum supplementation on bone mineral density in infant cynomolgus macaques

Insulin-like growth factor 1 (IGF1) is a regulator of human growth during infancy and childhood, known to promote bone and muscle growth as well as lipid accumulation. This study aimed to investigate the effects of formula milk with or without IGF1 supplementation (in the form of pure IGF1 or bovine colostrum) on growth and body composition in infant cynomolgus macaques during the first 6 months of life. Three groups of infants were nursery-reared and received formula milk with or without IGF1 or bovine colostrum supplementation for 4 months, and a fourth group consisting of breast-fed infants was included for comparison (n=6 for each group). Ranked-based analysis of covariance was used to detect differences between adjusted means for sex. No differences in weight, height, fat mass, and fat-free mass could be detected between groups. However, bone mineral density (BMD) was significantly different between groups at the end of formula feeding. Infants that received bovine colostrum supplementation displayed higher mean BMD than infants of all other groups, with no differences between the latter three groups. In conclusion, our results suggest that supplementation with bovine colostrum can enhance BMD in formula-fed infants, an effect that apparently does not depend on IGF1. Bovine colostrum supplementation could be beneficial for long-term bone health in infants with suboptimal bone growth.

The Associations of Height-for-Age, Weight-for-Age, and Weight-for-Height With Pediatric Acute Lymphoblastic Leukemia

Height at diagnosis has been analyzed in connection with acute lymphoblastic leukemia (ALL). Most prior studies have compared cases to national reference data derived from previous birth cohorts. Our objective was to determine the association of height-for-age Z score (HAZ) at time of diagnosis with the odds ratio (OR) of ALL in a case-control study (N=498) with a contemporaneous population of age-matched, sex-matched, and ethnicity-matched controls. We hypothesized that cases would have greater mean HAZ at time of diagnosis/interview, after adjustment for weight-for-age (WAZ) and weight-for-height (WHZ). HAZ was not associated with ALL. For each 1 SD increase in WAZ the OR of ALL was 0.83 (95% confidence interval [CI], 0.68-0.99). The OR of ALL was increased among children who had either a WAZ ≤-2 (OR, 5.10; 95% CI, 1.85-16.75) or WHZ of ≤-2 (OR, 5.27; 95% CI, 1.65-23.61). Previous findings of taller height among ALL cases may arise from the choice of control populations. Children with low WAZ or WHZ were at increased odds of ALL.

Higher Maternal Protein Intake during Pregnancy Is Associated with Lower Cord Blood Concentrations of Insulin-like Growth Factor (IGF)-II, IGF Binding Protein 3, and Insulin, but Not IGF-I, in a Cohort of Women with High Protein Intake

Background: Prenatal exposure to dietary protein may program growth-regulating hormones, consequently influencing early-life growth patterns and later risk of associated chronic diseases. The insulin-like growth factor (IGF) axis is of particular interest in this context given its influence on pre- and postnatal growth and its sensitivity to the early nutritional environment.Objective: Our objective was to examine associations of maternal protein intake during pregnancy with cord blood concentrations of IGF-I, IGF-II, IGF binding protein-3 (IGFBP-3), and insulin.Methods: We studied 938 mother-child pairs from early pregnancy through delivery in the Project Viva cohort. Using multivariable linear regression models adjusted for maternal race/ethnicity, education, income, smoking, parity, height, and gestational weight gain and for child sex, we examined associations of second-trimester maternal protein intake [grams per kilogram (weight before pregnancy) per day], as reported on a food frequency questionnaire, with IGF-I, IGF-II, IGFBP-3, and insulin concentrations in cord blood. We also examined how these associations may differ by child sex and parity.Results: Mothers were predominantly white (71%), college-educated (64%), and nonsmokers (67%). Mean ± SD protein intake was 1.35 ± 0.35 g ⋅ kg^-1 ⋅ d^-1 Each 1-SD increment in second-trimester protein intake corresponded to a change of -0.50 ng/mL (95% CI: -2.26, 1.26 ng/mL) in IGF-I and -0.91 μU/mL (95% CI: -1.45, -0.37 μU/mL) in insulin. Child sex and parity modified associations of maternal protein intake with IGF-II and IGFBP-3: protein intake was inversely associated with IGF-II in girls (P-interaction = 0.04) and multiparous mothers (P-interaction = 0.05), and with IGFBP-3 in multiparous mothers (P-interaction = 0.04).Conclusions: In a cohort of pregnant women with relatively high mean protein intakes, higher intake was associated with lower concentrations of growth-promoting hormones in cord blood, suggesting a pathway that may link higher protein intake to lower fetal growth. This trial was registered at clinicaltrials.gov as NCT02820402.

Enhanced nutrition improves growth and increases blood adiponectin concentrations in very low birth weight infants

Background

Adequate nutrient supply is essential for optimal postnatal growth in very low birth weight (VLBW, birth weight<1,500 g) infants. Early growth may influence the risk of metabolic syndrome later in life.

Objective

To evaluate growth and blood metabolic markers (adiponectin, leptin, and insulin-like growth factor-1 (IGF-1)) in VLBW infants participating in a randomized nutritional intervention study.

Design

Fifty VLBW infants were randomized to an enhanced nutrient supply or a standard nutrient supply. Thirty-seven infants were evaluated with growth measurements until 2 years corrected age (CA). Metabolic markers were measured at birth and 5 months CA.

Results

Weight gain and head growth were different in the two groups from birth to 2 years CA (weight gain: p_interaction=0.006; head growth: p_interaction=0.002). The intervention group improved their growth z-scores after birth, whereas the control group had a pronounced decline, followed by an increase and caught up with the intervention group after discharge. At 5 months CA, adiponectin concentrations were higher in the intervention group and correlated with weight gain before term (r=0.35) and nutrient supply (0.35≤r≤0.45). Leptin concentrations correlated with weight gain after term and IGF-1 concentrations with length growth before and after term and head growth after term (0.36≤r≤0.53).

Conclusion

Enhanced nutrient supply improved early postnatal growth and may have prevented rapid catch-up growth later in infancy. Adiponectin concentration at 5 months CA was higher in the intervention group and correlated positively with early weight gain and nutrient supply. Early nutrition and growth may affect metabolic markers in infancy.

Clinical Trial Registration (ClinicalTrials.gov) no.: NCT01103219

Maternal protein intake during pregnancy and linear growth in the offspring

BACKGROUND

Observational and experimental evidence demonstrates that protein intake in infancy programs linear growth. To our knowledge, few studies have examined prenatal maternal protein intake.

OBJECTIVE

Our objective was to examine associations of maternal protein intake during pregnancy with offspring linear growth.

DESIGN

We analyzed data from 1961 mother-child pairs in Project Viva. We assessed first- and second-trimester diet with the use of food-frequency questionnaires and analyzed protein intake as grams per kilogram prepregnancy weight per day. We used research measures of offspring length at birth and in infancy (∼6 mo), early childhood (∼3 y), and midchildhood (∼7 y), as well as clinical growth measures obtained from after birth through midchildhood. We calculated sex-specific birth length z scores for gestational age with the use of international reference data. We used mixed models with repeated length measures to predict individual length gain velocities for birth to <6 mo and 6 mo to 7 y of age, then used these velocities as outcomes in adjusted linear regression models with maternal protein intake as the main predictor.

RESULTS

Mean (range) second-trimester protein intake was 1.4 g · kg-1 · d-1 (0.3-3.1 g · kg-1 · d-1). After adjusting for maternal sociodemographics, gestational weight gain, maternal and paternal height, and (for postdelivery outcomes) child sex, gestational age, and breastfeeding duration, each 1-SD (0.36 g · kg-1 · d-1) increment in second-trimester protein intake corresponded to a -0.10 (95% CI: -0.18, -0.03) change in birth length z score, a -0.03 cm/mo (95% CI: -0.05, -0.01 cm/mo) change in slope of length growth from birth to <6mo, and a -0.09 cm/y (95% CI: -0.14, -0.05 cm/y) change in slope of length growth from 6 mo to midchildhood. Results were similar for first-trimester intake.

CONCLUSIONS

In a population with relatively high protein intake during pregnancy, higher protein intake was associated with shorter offspring birth length and slower linear growth into midchildhood. Results suggest that higher protein intake during pregnancy does not increase fetal and child growth and may even reduce early length growth. Project Viva was registered at clinicaltrials.gov as NCT02820402.

Low Protein Formula: Consequences of Quantitative Effects of Pre-analytical Factors on Amino Acid Concentrations in Plasma of Healthy Infants

OBJECTIVE

Quantifying pre-analytical effects of postprandial sampling delay and daily protein intake on plasma amino acid concentrations in healthy infants fed formula with low protein content (1.8-1.9 g/100 kcal). Intake of formula with higher protein content bears a risk for later obesity (Kirchberg, J Clin Endocrinol Metab 100(1):149-158, 2015). Formulas containing less than 1.8 g protein might be adequate but not safe (Fomon, J Pediatr Gastroenterol Nutr 28:495-501, 1999). With on-demand feeding reproducible controls of indispensible amino acid concentration cannot be made at trough level.

METHODS

Data of 102 healthy infants aged 1 month and 79 aged 4 months fed formula with low protein content were obtained from a previous study (Haschke-Becher, J Inherit Metab Dis 39(1):25-37, 2016). They were analysed by multiple regression. Independent variables were the postprandial sampling delay from 2.25 to 4.5 h and the daily protein intake. Dependant variables were the amino acid concentrations. The combined effect was calculated with the natural logarithm of the amino acid concentration.

RESULTS

Most amino acids fitted a significant exponential decrease due to the sampling delay, except of aspartate, citrulline, glutamine, glutamate, histidine, tryptophan and tyrosine at 1 month; and at 4 months except of citrulline, glutamine, glutamate, glycine and ornithine. Significant effects of protein intake were found for lysine and serine at 1 month and for glutamate at 4 months of age. Lowest limits of significant amino acid concentrations were calculated by extrapolation of sampling delay to 5 h and using the 10th percentile after back-transformation to μmol/L. A procedure to avoid the pitfall of overestimating amino acid concentration is presented.

Breast milk nutrient content and infancy growth

Aim

Benefits of human breast milk (HM) in avoiding rapid infancy weight gain and later obesity could relate to its nutrient content. We tested the hypothesis that differential HM total calorie content (TCC) or macronutrient contents may be associated with infancy growth.

Methods

HM hindmilk samples were collected at ages 4–8 weeks from 614 mothers participating in a representative birth cohort, with repeated infancy anthropometry. HM triglyceride (fat), lipid analytes and lactose (carbohydrate) were measured by ¹H‐NMR, and protein content by the Dumas method. TCC and %macronutrients were determined.

Results

In 614 HM samples, fat content was as follows: [median(IQR)]: 2.6 (1.7–3.6) g/100 mL, carbohydrate: 8.6 (8.2–8.8) g/100 mL, protein: 1.2 (1.1–1.2) g/100 mL; TCC: 61.8 (53.7–71.3) kcal/100 mL. HM of mothers exclusively breast feeding vs. mixed feeding was more calorific with higher %fat, lower %carbohydrate and lower %protein. Higher HM TCC was associated with lower 12‐months body mass index (BMI)/adiposity, and lower 3–12 months gains in weight/BMI. HM %fat was inversely related to 3–12 months gains in weight, BMI and adiposity, whereas %carbohydrate was positively related to these measures. HM %protein was positively related to 12‐months BMI.

Conclusion

HM analysis showed wide variation in %macronutrients. Although data on milk intakes were unavailable, our findings suggest functional relevance of HM milk composition to infant growth.

Childhood growth in boys with congenital hypogonadotropic hypogonadism

BACKGROUND

We describe childhood growth patterns in a series of well-characterized patients with congenital hypogonadotropic hypogonadism (CHH) with special emphasis on genotype-phenotype correlation.

METHODS

We retrospectively evaluated the growth charts of 36 males with CHH (27 from Finland and 9 from Denmark). Fifteen patients (42%) had representative growth measurements during the first year of life. Genetically verified diagnosis of CHH was made in 15 (42%) patients (KAL1, FGFR1, GNRHR, or PROK2).

RESULTS

We found a deceleration of growth rate during early childhood. The mean (SD) length standard deviation score (SDS) at birth (0.2 (1.6) SDS) decreased significantly during the first 3 (to -0.9 (1.2) SDS) and 6 mo of life (to -0.7 (1.3) SDS). At the average age of 3 y, mean height SDS (-0.2 (1.3) SDS) did not differ from mid-parental target height (MPH). Mean height SDS reached its nadir (-1.7 (1.4) SDS) at an average age of 15.8 (0.8) years reflecting pubertal failure. Final heights did not differ from MPH. No clear genotype-growth associations emerged.

CONCLUSION

Moderate postnatal length deflection is a novel feature of CHH and may reflect early androgen deficiency. Childhood growth patterns are not of clinical value in targeting molecular genetic diagnosis of CHH.

Role of selected amino acids on plasma IGF-I concentration in infants

PURPOSE

Insulin-like growth factor-I (IGF-I) is related to growth and its secretion is modified by protein intake in early infancy. We examined the relationship of dietary protein and circulating amino acids on plasma IGF-I levels and early growth.

METHODS

Healthy formula-fed infants (n = 213) were randomly assigned to receive either a protein-reduced infant formula with alpha-lactalbumin-enriched whey and free tryptophan and phenylalanine (IF) or an isocaloric standard formula without free amino acids (CF) for the first 120 days of life. A group of breastfed (BF) infants was studied as a non-randomized reference cohort. Biochemical variables were measured shortly after birth (subpopulation) and at an age of 120 days. A path analysis was used to explore the relationship between IGF-I, insulin and amino acids. Results are derived from secondary analyses of a randomized controlled trial.

RESULTS

Plasma concentrations of IGF-I at 120 days were significantly higher in IF than in CF infants [58.5 (15.0) vs. 53.7 (9.95) ng/mL; p = 0.020]. BF infants showed lower IGF-I concentrations of 41.6 (10.7) ng/mL. All amino acids but Thr and Cit had a more marked effect on insulin than on IGF-I level. Considering weight, sex and feeding group, Trp explained an equal percentage of variance of IGF-I and insulin (total R ² 12.5 % of IGF-I and 12.3 % of insulin), while branched-chain AA explained an up to twofold higher variance of insulin than IGF-I. Compared to CF, IF explained 18.9 % of the IGF-I level (p = 0.03), while for insulin no direct effect was detectable.

CONCLUSION

Higher IGF-I concentrations and growth velocities in infants receiving protein-reduced IF indicate that the protein concentration of an infant formula alone does not control IGF-I levels and growth. Other components (e.g., selected amino acids) of infant formulae might control directly or indirectly via insulin influence IGF-I.

Effect of dietary protein on plasma insulin-like growth factor-1, growth, and body composition in healthy term infants: a randomised, double-blind, controlled trial (Early Protein and Obesity in Childhood (EPOCH) study)

The effect of protein intake on growth velocity in infancy may be mediated by insulin-like growth factor-1 (IGF-1). This study aimed to determine the effects of formulae containing 1·8 (F1·8) or 2·7 g (F2·7) protein/418·4 kJ (100 kcal) on IGF-1 concentrations and growth. Healthy term infants were randomly assigned to receive F1·8 (n 74) or F2·7 (n 80) exclusively for the first 4 months of life. A group of breast-fed infants (n 84) was followed-up simultaneously (reference). Growth and body composition were measured at 0·5, 4, 6, 12, 36, 48 and 60 months of life. The IGF-1 concentrations at 4 months (primary outcome) were similar in the F1·8 (67·1 (sd 20·8) ng/l; n 70) and F2·7 (71·2 (sd 27·5) ng/l; n 73) groups (P=0·52). Both formula groups had higher IGF-1 concentrations than the breast-fed group at 4 and 9 months of age (P≤0·0001). During the first 60 months of life, anthropometric parameters in the F1·8 group were lower compared with the F2·7 group, and the differences were significant for head circumference from 2 to 60 months, body weight at 4 and 6 months and length at 9, 12 and 36 months of age. There were no significant differences in body composition between these two groups at any age. We conclude that, in formula-fed infants, although increased protein intake did not affect the IGF-1 concentration during the first 12 months of life, it did affect length and head circumference growth, suggesting that factors other than IGF-1 could play roles in determining growth velocity.

Effects on childhood body habitus of feeding large volumes of cow or formula milk compared with breastfeeding in the latter part of infancy

BACKGROUND

There is controversy over whether a lack of breastfeeding is related to obesity development.

OBJECTIVE

We examined the effects of feeding different types of milk in late infancy on childhood growth.

DESIGN

A cohort of 1112 term, singleton children (born in 1992) from the Avon Longitudinal Study of Parents and Children, United Kingdom, were studied prospectively. Food records collected at 8 mo of age were used to define the following 5 mutually exclusive feeding groups on the basis of the type and amount of milk consumed: breast milk (BM), <600 mL formula milk/d (FMlow), ≥600 mL formula milk/d (FMhigh), <600 mL cow milk/d (CMlow), and ≥600 mL cow milk/d (CMhigh). Weight, height, and BMI were measured at 14 time points from birth to 10 y of age, and SD scores (SDSs) were calculated. Dietary energy and macronutrient intakes were available at 7 time points.

RESULTS

CMhigh children were heavier than were BM children from 8 mo to 10 y of age with weight differences (after adjustment for maternal education, smoking, and parity) ≥0.27 SDSs and an average of 0.48 SDSs. The maximum weight difference was at 18 mo of age (0.70 SDS; 95% CI: 0.41, 1.00 SDS; P = <0.0001). CMhigh children were taller at some ages (25-43 mo; P < 0.01) and had greater BMI SDSs from ≥8 mo of age (at 9 y of age; P = 0.001). FMhigh children were heavier and taller than were BM children from 8 to 37 mo of age. There were marked dietary differences between milk groups at 8 mo of age, some of which persisted to 18 mo of age. Adjustments for current energy and protein intakes did not attenuate the growth differences observed.

CONCLUSIONS

The feeding of high volumes of cow milk in late infancy is associated with faster weight and height gain than is BM feeding. The feeding of bottle-fed infants with high volumes of cow milk in late infancy may have a persisting effect on body habitus through childhood.

The Association between Newborn Regional Body Composition and Cord Blood Concentrations of C-Peptide and Insulin-Like Growth Factor I

Background

Third trimester fetal growth is partially regulated by C-peptide and insulin-like growth factor I (IGF-I). Prenatal exposures including maternal obesity and high gestational weight gain as well as high birth weight have been linked to subsequent metabolic disease. We evaluated the associations between newborn regional body composition and cord blood levels of C-peptide and IGF-I.

Methods

We prospectively included obese and normal-weight mothers and their newborns; cord blood was collected and frozen. Analyses of C-peptide and IGF-I were performed simultaneously, after recruitment was completed. Newborn regional body composition was assessed with dual-energy X-ray absorptiometry scanning (DXA) within 48 hours of birth.

Results

Three hundred thirty-six term infants were eligible to participate in the study; of whom 174 (52%) infants had cord blood taken. Total, abdominal and arm and leg fat mass were positively associated with C-peptide (p < 0.001). Arm and leg fat mass was associated with IGF-I concentration: 28 g [95% confidence interval: 4, 53] per doubling of IGF-I. There was no association between total or abdominal fat mass and IGF-I. Fat-free mass was positively associated with both C-peptide (p < 0.001) and IGF-I (p = 0.004).

Conclusion

Peripheral fat tissue accumulation was associated with cord blood C-peptide and IGF-I. Total and abdominal fat masses were related to C-peptide but not to IGF-I. Thus, newborn adiposity is partially mediated through C-peptide and early linear growth is associated with IGF-I.

Obesity and breastfeeding: The strength of association

Obesity and attendant co-morbidities are an emergent problem in public health. Much attention has focused on prevention, especially during the perinatal period. Breastfeeding is considered a possible protective factor for obesity in childhood, influencing gene-neuroendocrine-environment-lifestyle interaction. Therefore, breastfeeding and its longer duration are probably associated with lower development of childhood obesity. Through human milk, but not formula, the child assumes greater bioactive factors contributing to immunological, endocrine, development, neural and psychological benefits. Contrarily, other studies did not confirm a critical role of breast milk. Confounding factors, especially maternal pre-pregnancy overweight, may influence breastfeeding effects. This review summarises what is known about the possible relationship between breastfeeding and prevention of obesity development.

CONCLUSION

Breastfeeding appears to represent a protective factor for obesity in childhood, although evidence is still controversial and underlying mechanisms unclear. Further research is needed to improve knowledge on overweight/obesity and breastfeeding.

Lipidomic analyses, breast- and formula-feeding, and growth in infants

OBJECTIVE

To evaluate lipidomic differences between breast- and formula-fed infants.

STUDY DESIGN

We utilized high-resolution mass-spectrometry methods to analyze 3.2 mm dried blood spot samples collected at ages 3 months (n = 241) and 12 months (n = 144) from a representative birth cohort study. Lipidomic profiles were compared between infants exclusively breast-fed, formula-fed, or mixed-fed, and related to 12-month infancy weight. Data analysis included supervised multivariate statistics (partial least squares discriminant analysis), and univariate analysis with correction for multiple testing.

RESULTS

Distinct differences in 3-month lipidomic profiles were observed between exclusively breast-fed and formula-fed infants; mixed-fed infants showed intermediate profiles. Principle lipidomic characteristics of breast-fed infants were lower total phosphatidylcholines (PCs), with specifically lower short chain unsaturated PC but higher long chain polyunsaturated PC; higher cholesterol esters; and variable differences in sphingomyelins. At 12 months, lipidomic profiles were markedly different to those at 3 months, and differences between the earlier breast/formula/mixed-feeding groups were no longer evident. However, several specific lipid species, associated with breast-feeding at 3 months, also correlated with differences in 3- to 12-month weight.

CONCLUSIONS

State-of-the-art dried blood spot sample lipidomic profiling demonstrated striking differences between breast-fed and formula-fed infants. Although these changes diminished with age, breast-fed lipidomic profiles at 3 months were associated with infancy weight and could potentially represent biomarkers of infant nutrition.

Dietary proteins and IGF I levels in preterm infants: determinants of growth, body composition, and neurodevelopment

It has been demonstrated that a high-protein diet in preterm born infants during the first weeks of life may enable a growth rate equal to that seen in utero and may also result in a better long-term neurodevelopmental outcome. This diet may limit immediate postnatal growth retardation and may hence lower the risk of increased fat deposition after birth leading to the metabolic syndrome in later life. Insulin-like growth factor I (IGF I) has proven to play an important role in early postnatal growth of preterm infants, but also seems to have a persisting influence on body composition in childhood. Furthermore, increased IGF I concentrations in preterm infants have been associated with improved neurodevelopmental outcome. This review will elaborate on the role of dietary proteins and IGF I on growth, body composition, and neurodevelopment of preterm infants. Possible causal pathways will be explored and areas for future research will be proposed.

IGF-I at 9 and 36 months of age — relations with body composition and diet at 3 years — the SKOT cohort

OBJECTIVE

High infancy levels of insulin-like growth factor-I (IGF-I) have been associated with increased linear growth and fat-free mass (FFM) but also with risk of obesity. This paper examines how IGF-I at 9 and 36 months relates to diet and body composition.

DESIGN

Healthy term infants from the prospective cohort study, SKOT, were examined at 9 and 36 months with anthropometry, bioelectrical impedance (36 months), 7-day food records and blood analysis of IGF-I and IGFBP-3 by chemiluminescent immunometric assay.

RESULTS

IGF-I at 36 months (n = 229) was positively correlated with 9 months values and values were considerably higher in girls (43%). Children breastfed at 9 months had lower IGF-I concentrations at 9 months but reached the same IGF-I concentrations at 36 months as infants not breastfed at 9 months. IGF-I at 36 months was positively associated with height, weight, BMI, predicted FFM and FFM index (FFM/height (kg/m2)). Although there also was a positive association with predicted fat mass (FM) there was no association with FM index (FM/height (kg/m2)). Further, a negative association with skin fold thickness was observed. A change in IGF-I from 9–36 months was positively related to FFM and FFM index but not BMI, FM and FM index. No associations were seen between IGF-I and current intake of milk, meat or protein energy percentage, but both fat and saturated fat energy percentage were negatively associated with IGF-I.

CONCLUSION

IGF-I concentrations were positively associated with growth but not with adiposity at this age. However, the higher tempo of growth may influence age at adiposity rebound and thereby later risk of obesity. Milk and protein intake at 36 months did not influence IGF-I but there was a negative association with intake of fat and saturated fat. The implications of this finding for development of obesity need further exploration.

Impact on offspring methylation patterns of maternal gestational diabetes mellitus and intrauterine growth restraint suggest common genes and pathways linked to subsequent type 2 diabetes risk

Size at birth, postnatal weight gain, and adult risk for type 2 diabetes may reflect environmental exposures during developmental plasticity and may be mediated by epigenetics. Both low birth weight (BW), as a marker of fetal growth restraint, and high birth weight (BW), especially after gestational diabetes mellitus (GDM), have been linked to increased risk of adult type 2 diabetes. We assessed DNA methylation patterns using a bead chip in cord blood samples from infants of mothers with GDM (group 1) and infants with prenatal growth restraint indicated by rapid postnatal catch-up growth (group 2), compared with infants with normal postnatal growth (group 3). Seventy-five CpG loci were differentially methylated in groups 1 and 2 compared with the controls (group 3), representing 72 genes, many relevant to growth and diabetes. In replication studies using similar methodology, many of these differentially methylated regions were associated with levels of maternal glucose exposure below that defined by GDM [the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study] or were identified as changes observed after randomized periconceptional nutritional supplementation in a Gambian cohort characterized by maternal deprivation. These studies provide support for the concept that similar epigenetic modifications may underpin different prenatal exposures and potentially increase long-term risk for diseases such as type 2 diabetes.

Growth in preterm infants until six months postterm: the role of insulin and IGF-I

BACKGROUND/AIMS

Since insulin-like growth factor type I (IGF-I) and insulin regulate growth in term infants, they were studied in relation to nutrient intake and growth until 6 months corrected age (CA) in preterm infants.

METHODS

In 138 preterm infants (51% male, gestational age (expressed as median (IQR)) 30.6 (1.9) weeks, birth weight 1,368 (389) g) weight SDS, length SDS, IGF-I, and insulin were measured at term age, 3 and 6 months CA.

RESULTS

IGF-I and insulin at term age were associated with weight SDS and length SDS at term age and 3 months CA. IGF-I and insulin at 3 months CA were associated with weight SDS and length SDS at 3 and 6 months CA. IGF-I and insulin at term age were negatively associated with gain in weight SDS and gain in length SDS between term age and 6 months CA (IGF-I: β = -1.03, 95% CI -1.65;-0.41, p = 0.001 and β = -0.78, 95% CI -1.32;-0.23, p = 0.005; insulin: β = -0.19, 95% CI -0.37;-0.01, p = 0.044 and β = -0.18, 95% CI -0.35;-0.01, p = 0.035). Nutrient intake was not associated with IGF-I or insulin.

CONCLUSIONS

The present study suggests that IGF-I and insulin are important growth regulators in preterm infants until 6 months CA, independent of nutrient intake.

The development and validation of a fast and robust dried blood spot based lipid profiling method to study infant metabolism

Early life exposures and metabolic programming are associated with later disease risk. In particular lipid metabolism is thought to play a key role in the development of the metabolic syndrome and insulin resistance in later life. Investigative studies of metabolic programming are limited by the ethics and practicalities of sample collection in small infants. Dried blood spots on filter paper, derived from heel pricks are considered as the most suitable option for this age group. We validated a novel lipid profiling method, based on high resolution mass spectrometry to successfully determine the lipid composition of infants using dried blood spots. The spotting and air drying of blood on paper has noticeable effects on many of the lipids, leading to lipid oxidation and hydrolysis, which demand careful interpretation of the obtained data. We compared the lipid profiles from plasma or whole blood samples and the results from dried blood spots to determine if these revealed the same inter-subject differences. The results from dried blood spots were no less reproducible than other lipid profiling methods which required comparatively larger sample volumes. Therefore, lipid profiles obtained from dried blood spots can be successfully used to monitor infancy lipid metabolism and we show significant differences in the lipid metabolism of infants at age 3 versus 12 months.

[Does childhood obesity affect sexual development?]

The process of pubertal development is only partly understood and is influenced by many different factors. During the twentieth century there was a general trend toward earlier pubertal development. Fat mass is thought to be a major inducer of puberty. Owing to the rising epidemic of childhood obesity, the relationship between body composition in children and the rate and timing of puberty needs to be investigated. Some studies suggest that central obesity is associated with an earlier onset of pubertal development. Rapid weight gain in early life is linked to advanced puberty in both sexes. A clear correlation exists between increasing body mass index (BMI) and earlier pubertal development in girls. In boys the data are controversial: The majority of studies propose that there is an earlier puberty and voice break in obese boys, but some studies show the opposite. There are several factors and mechanisms that seem to link obesity and puberty, for example, leptin, adipocytokines, and gut peptides. Important players include genetic variation and environmental factors (e.g., endocrine-disrupting chemicals). This article presents the latest studies and evidence on this topic, underlining the inconsistencies in the data and, therefore, the need for further research in this area.

Analysis of the relationship of insulin-like growth factor-1 to the growth velocity and feeding of healthy infants

CONTEXT

Infancy is the fastest growth period in a child's development after birth, but little is known about hormonal regulation mechanism for the growth and development of this period.

OBJECTIVE

The objective of this study is to analyze the trend of serum IGF-1 levels in healthy infants and the relationship of IGF-1 to the growth velocity and feeding method of infants.

DESIGN

Population-based birth cohort study.

SETTING

The study was conducted in the Third Hospital of Peking University.

PARTICIPANTS

Study participants were 484 healthy infants, all of whom were full-term and appropriate for gestational age (238 boys and 246 girls).

INTERVENTIONS

Interventions were anthropometrical measurements, feeding methods recorded every 1 to 2 months and serum samples (2, 4, 6, 8, 10,12 months).

MAIN OUTCOME MEASURES

Height, weight, feeding methods and serum IGF-1 were the main outcome measures.

RESULTS

Serum IGF-1 levels decreased in the following 2 months in boys but in females levels remained relatively high between 2 to 3 months after birth and then started to decrease. It reached the lowest point at Months 7-8, and was on a slow rise in both male infants and female infants thereafter. Serum IGF-1 levels were significantly higher in female infants [112.65 ng/ml (CI 91.82, 133.89)] than in male infants [74.38 ng/ml (CI 53.14, 95.61)] at early infancy. Infants fed with human milk had lower serum IGF-1 levels than infants fed with formula milk or human milk plus formula milk (66.94 ± 45.85 ng/ml, 72.56 ± 36.55 ng/ml, 79.89 ± 51.79 ng/ml, respectively; P = 0.019). IGF-1 levels were positively correlated to the growth velocity of body length (P<0.01).

CONCLUSION

This study provides the trend for IGF-1 levels at infancy. It is highly possible that IGF-1 plays an important role in the regulation and control of length increases in infants, and feeding method influences serum IGF-1 levels.

Breastfeeding and its prospective association with components of the GH-IGF-Axis, insulin resistance and body adiposity measures in young adulthood--insights from linear and quantile regression analysis

BACKGROUND

Breastfeeding may lower chronic disease risk by long-term effects on hormonal status and adiposity, but the relations remain uncertain.

OBJECTIVE

To prospectively investigate the association of breastfeeding with the growth hormone- (GH) insulin-like growth factor- (IGF) axis, insulin sensitivity, body composition and body fat distribution in younger adulthood (18-37 years).

DESIGN

Data from 233 (54% female) participants of a German cohort, the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, with prospective data on infant feeding were analyzed. Multivariable linear as well as quantile regression were performed with full breastfeeding (not: ≤ 2, short: 3-17, long: >17 weeks) as exposure and adult IGF-I, IGF binding proteins (IGFBP) -1, -2, -3, homeostasis model assessment of insulin resistance (HOMA-IR), fat mass index, fat-free mass index, and waist circumference as outcomes.

RESULTS

After adjustment for early life and socio-economic factors, women who had been breastfed longer displayed higher adult IGFBP-2 (p(trend) = 0.02) and lower values of HOMA-IR (p(trend) = 0.004). Furthermore, in women breastfeeding duration was associated with a lower mean fat mass index (p(trend) = 0.01), fat-free mass index (p(trend) = 0.02) and waist circumference (p(trend) = 0.004) in young adulthood. However, there was no relation to IGF-I, IGFBP-1 and IGFBP-3 (all p(trend) > 0.05). Associations for IGFBP-2 and fat mass index were more pronounced at higher, for waist circumference at very low or high percentiles of the distribution. In men, there was no consistent relation of breastfeeding with any outcome.

CONCLUSIONS

Our data suggest that breastfeeding may have long-term, favorable effects on extremes of adiposity and insulin metabolism in women, but not in men. In both sexes, breastfeeding does not seem to induce programming of the GH-IGF-axis.

Does insulin-like growth factor-1 mediate protein-induced kidney growth in infants? A secondary analysis from a randomized controlled trial

BACKGROUND

Animal models have shown that insulin-like growth factor I (IGF-I) may mediate protein-induced kidney growth. Our aim was to analyze the effect of IGF-I on protein-induced kidney growth in healthy infants.

METHODS

This is a secondary analysis of a randomized trial that compared growth of infants fed with a higher-protein (HP) (n = 169) vs. lower-protein (LP) (n = 182) formula (in the first year of life). Outcome measures were anthropometric parameters, kidney volume (cm(3)), and total and free IGF-I (ng/ml).

RESULTS

The highest levels of total and free IGF-I were found in the HP group. Both parameters correlated significantly with BMI z-score (r = 0.229, P < 0.001 and r = 0.223, P < 0.001, respectively), kidney volume (r = 0.115, P = 0.006 and r = 0.208, P < 0.001, respectively), and kidney volume/body length (r = 0.109, P = 0.010 and r = 0.194, P < 0.001, respectively) at 6 mo. Linear regression analyses showed a significant effect of free IGF-I on kidney volume in models, including significant effects of HP formula and anthropometry. The structural equation model revealed a significant direct effect of the HP formula on kidney volume and an indirect effect mediated by free IGF-I.

CONCLUSION

This study suggests that IGF-I partly mediates protein-induced kidney growth in healthy infants. IGF-I could be involved in a pathway for the programming of the renal system.

The biology of retinopathy of prematurity: how knowledge of pathogenesis guides treatment

Retinopathy of prematurity occurs because the retina of a preterm infant at birth is incompletely vascularized, and if the postnatal environment does not match the in utero environment that supported retinal development, the vessels and neural retina will not grow normally. Risk factors determined from many clinical studies and animal studies fall into 2 categories: prenatal factors and postnatal factors.

Ultrasound estimates of visceral and subcutaneous-abdominal adipose tissues in infancy

Other imaging techniques to quantify internal-abdominal adiposity (IA-AT) and subcutaneous-abdominal adiposity (SCA-AT) are frequently impractical in infants. The aim of this study was twofold: (a) to validate ultrasound (US) visceral and subcutaneous-abdominal depths in assessing IA-AT and SCA-AT from MRI as the reference method in infants and (b) to analyze the association between US abdominal adiposity and anthropometric measures at ages 3 months and 12 months. Twenty-two infants underwent MRI and US measures of abdominal adiposity. Abdominal US parameters and anthropometric variables were assessed in the Cambridge Baby Growth Study (CBGS), n = 487 infants (23 girls) at age 3 months and n = 495 infants (237 girls) at 12 months. US visceral and subcutaneous-abdominal depths correlated with MRI quantified IA-AT (r = 0.48, P < 0.05) and SCA-AT (r = 0.71, P < 0.001) volumes, respectively. In CBGS, mean US-visceral depths increased by ~20 % between ages 3 and 12 months (P < 0.0001) and at both ages were lower in infants breast-fed at 3 months than in other infants. US-visceral depths at both 3 and 12 months were inversely related to skinfold thickness at birth (P = 0.03 and P = 0.009 at 3 and 12 months, resp.; adjusted for current skinfold thickness). In contrast, US-subcutaneous-abdominal depth at 3 months was positively related to skinfold thickness at birth (P = 0.004). US measures can rank infants with higher or lower IA-AT and SCA-AT. Contrasting patterns of association with visceral and subcutaneous-abdominal adiposities indicate that they may be differentially regulated in infancy.

Effects of promoting longer-term and exclusive breastfeeding on adiposity and insulin-like growth factor-I at age 11.5 years: a randomized trial

IMPORTANCE

Evidence that longer-term and exclusive breastfeeding reduces child obesity risk is based on observational studies that are prone to confounding.

OBJECTIVE

To investigate effects of an intervention to promote increased duration and exclusivity of breastfeeding on child adiposity and circulating insulin-like growth factor (IGF)-I, which regulates growth.

DESIGN, SETTING, AND PARTICIPANTS

Cluster-randomized controlled trial in 31 Belarusian maternity hospitals and their affiliated clinics, randomized into 1 of 2 groups: breastfeeding promotion intervention (n = 16) or usual practices (n = 15). Participants were 17,046 breastfeeding mother-infant pairs enrolled in 1996 and 1997, of whom 13,879 (81.4%) were followed up between January 2008 and December 2010 at a median age of 11.5 years.

INTERVENTION

Breastfeeding promotion intervention modeled on the WHO/UNICEF Baby-Friendly Hospital Initiative (World Health Organization/United Nations Children's Fund).

MAIN OUTCOME MEASURES

Body mass index (BMI), fat and fat-free mass indices (FMI and FFMI), percent body fat, waist circumference, triceps and subscapular skinfold thicknesses, overweight and obesity, and whole-blood IGF-I. Primary analysis was based on modified intention-to-treat (without imputation), accounting for clustering within hospitals and clinics.

RESULTS

The experimental intervention substantially increased breastfeeding duration and exclusivity when compared with the control (43% vs 6% exclusively breastfed at 3 months and 7.9% vs 0.6% at 6 months). Cluster-adjusted mean differences in outcomes at 11.5 years of age between experimental vs control groups were: 0.19 (95% CI, -0.09 to 0.46) for BMI; 0.12 (-0.03 to 0.28) for FMI; 0.04 (-0.11 to 0.18) for FFMI; 0.47% (-0.11% to 1.05%) for percent body fat; 0.30 cm (-1.41 to 2.01) for waist circumference; -0.07 mm (-1.71 to 1.57) for triceps and -0.02 mm (-0.79 to 0.75) for subscapular skinfold thicknesses; and -0.02 standard deviations (-0.12 to 0.08) for IGF-I. The cluster-adjusted odds ratio for overweight/obesity (BMI ≥ 85th vs <85th percentile) was 1.18 (95% CI, 1.01 to 1.39) and for obesity (BMI ≥ 95th vs <85th percentile) was 1.17 (95% CI, 0.97 to 1.41).

CONCLUSIONS

AND RELEVANCE Among healthy term infants in Belarus, an intervention that succeeded in improving the duration and exclusivity of breastfeeding did not prevent overweight or obesity, nor did it affect IGF-I levels at age 11.5 years. Breastfeeding has many advantages but population strategies to increase the duration and exclusivity of breastfeeding are unlikely to curb the obesity epidemic.

TRIAL REGISTRATION

isrctn.org: ISRCTN37687716; and clinicaltrials.gov: NCT01561612.

Breast-feeding vs formula-feeding for infants born small-for-gestational-age: divergent effects on fat mass and on circulating IGF-I and high-molecular-weight adiponectin in late infancy

CONTEXT

Fetal growth restraint, if followed by rapid weight gain, confers risk for adult disease including diabetes. How breast-feeding may lower such risk is poorly understood. OBJECTIVE, STUDY PARTICIPANTS, INTERVENTION, OUTCOMES: In infants born small-for-gestational-age (SGA), we studied the effects of nutrition in early infancy (breast-feeding vs formula-feeding; BRF vs FOF) on weight partitioning and endocrine markers in late infancy. Body composition (by absorptiometry), fasting glycemia, insulin, IGF-I, and high-molecular-weight (HMW) adiponectin were assessed at 4 and 12 months in BRF controls born appropriate-for-GA (N = 31) and in SGA infants receiving BRF (N = 48) or FOF (N = 51), the latter being randomized to receive a standard formula (FOF1) or a protein-rich formula (FOF2).

SETTING

The study was conducted in a University Hospital.

RESULTS

SGA-BRF infants maintained a low fat mass and normal levels of IGF-I and HMW adiponectin. In contrast, SGA-FOF infants normalized their body composition by gaining more fat; this normalization was accompanied by a marked fall in HMW adiponectinemia and, in FOF2 infants, by elevated IGF-I levels. In late infancy, SGA-BRF infants were most sensitive to insulin, even more sensitive than appropriate-for-GA-BRF controls.

CONCLUSIONS

Because the health perspectives are better for SGA-BRF than for SGA-FOF infants, the present results suggest that FOF for SGA infants should aim at maintaining normal IGF-I and HMW-adiponectin levels rather than at normalizing body composition. Nutriceutical research for SGA infants may thus have to be redirected.

Peripubertal-onset but not adult-onset obesity increases IGF-I and drives development of lean mass, which may lessen the metabolic impairment in adult obesity

It has been suggested that adult metabolic dysfunction may be more severe in individuals who become obese as children compared with those who become obese later in life. To determine whether adult metabolic function differs if diet-induced weight gain occurs during the peripubertal age vs. if excess weight gain occurs after puberty, male C57Bl/6J mice were fed a low-fat (LF; 10% kcal from fat) or high-fat (HF; 60% kcal from fat) diet starting during the peripubertal period (pHF; 4 wk of age) or as adults (aHF; 12 wk of age). Both pHF and aHF mice were hyperinsulinemic and hyperglycemic, and both showed impaired glucose tolerance and insulin resistance compared with their LF-fed controls. However, despite a longer time on diet, pHF mice were relatively more insulin sensitive than aHF mice, which was associated with higher lean mass and circulating IGF-I levels. In addition, HF feeding had an overall stimulatory effect on circulating corticosterone levels; however, this rise was associated only with elevated plasma ACTH in the aHF mice. Despite the belief that adult metabolic dysfunction may be more severe in individuals who become obese as children, data generated using a diet-induced obese mouse model suggest that adult metabolic dysfunction associated with peripubertal onset of obesity is not worse than that associated with adult-onset obesity.

Body composition and circulating high-molecular-weight adiponectin and IGF-I in infants born small for gestational age: breast- versus formula-feeding

Prenatal growth restraint, if followed by postnatal overweight, confers risk for adult disease including diabetes. The mechanisms whereby neonatal nutrition may modulate such risk are poorly understood. We studied the effects of nutrition (breast-feeding [BRF] vs. formula-feeding [FOF]) on weight partitioning and endocrine state (as judged by high-molecular-weight [HMW] adiponectin and IGF-I) of infants born small for gestational age (SGA). Body composition (by absorptiometry), HMW adiponectin, and IGF-I were assessed at birth and 4 months in BRF infants born appropriate for gestational age (AGA; n = 72) and SGA infants receiving BRF (n = 46) or FOF (n = 56), the latter being randomized to receive a standard (FOF1) or protein-rich formula (FOF2). Compared with AGA-BRF infants, the catchup growth of SGA infants was confined to lean mass, independently of nutrition. Compared with AGA-BRF infants, SGA-BRF infants had normal HMW adiponectin and IGF-I levels at 4 months, whereas SGA-FOF infants had elevated levels of HMW adiponectin (particularly SGA-FOF1) and IGF-I (particularly SGA-FOF2). In conclusion, neonatal nutrition seems to influence endocrinology more readily than body composition of SGA infants. Follow-up will disclose whether the endocrine abnormalities in SGA-FOF infants can serve as early markers of an unfavorable metabolic course and whether they may contribute to design early interventions that prevent subsequent disease, including diabetes.

Early nutrition impact on the insulin-like growth factor axis and later health consequences

PURPOSE OF REVIEW

There is increasing interest in the role of insulin-like growth factor-I (IGF-I) in the relation between early growth and later risk of noncommunicable diseases (NCDs). This review presents and discusses a selection of recent publications on this topic.

RECENT FINDINGS

Nutrition during pregnancy and in preterm infants has an influence on IGF-I. Breastfeeding is associated with lower IGF-I values and the effect of early protein intake was confirmed in a large intervention study. IGF-I levels are associated with early obesity, but the relation is complex and differs with age. Further studies and reviews support that there is a programming of the IGF axis, with higher levels during early life being associated with lower levels in adulthood, which is likely to influence the risk of NCDs later in life.

SUMMARY

Recent studies support that IGF-I plays an important role in the complex association between early diet, growth and later health, but more studies are needed to better understand the role of IGF-I, especially in the early development of obesity. Studies with data on how IGF-I is influenced by early diet in studies of preterm infants and young children with undernutrition from low-income countries will be helpful in recommending optimal diets.