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

IGF-1 and IGF-2 as Molecules Linked to Causes and Consequences of Obesity from Fetal Life to Adulthood: A Systematic Review

This study examines the impact of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 2 (IGF-2) on various aspects of children's health-from the realms of growth and puberty to the nuanced characteristics of metabolic syndrome, diabetes, liver pathology, carcinogenic potential, and cardiovascular disorders. A comprehensive literature review was conducted using PubMed, with a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method employing specific keywords related to child health, obesity, and insulin-like growth factors. This study reveals associations between insulin-like growth factor 1 and birth weight, early growth, and adiposity. Moreover, insulin-like growth factors play a pivotal role in regulating bone development and height during childhood, with potential implications for puberty onset. This research uncovers insulin-like growth factor 1 and insulin-like growth factor 2 as potential biomarkers and therapeutic targets for metabolic dysfunction-associated liver disease and hepatocellular carcinoma, and it also highlights the association between insulin-like growth factors (IGFs) and cancer. Additionally, this research explores the impact of insulin-like growth factors on cardiovascular health, noting their role in cardiomyocyte hypertrophy. Insulin-like growth factors play vital roles in human physiology, influencing growth and development from fetal stages to adulthood. The impact of maternal obesity on children's IGF levels is complex, influencing growth and carrying potential metabolic consequences. Imbalances in IGF levels are linked to a range of health conditions (e.g., insulin resistance, glucose intolerance, metabolic syndrome, and diabetes), prompting researchers to seek novel therapies and preventive strategies, offering challenges and opportunities in healthcare.

Plasma vitamin B12 concentration is positively associated with cognitive development in healthy Danish 3-year-old children: the SKOT cohort studies

Adequate vitamin B₁₂ (B₁₂) and folate concentrations are essential for neural development in early childhood, but studies in well-nourished children are lacking. We investigated the relation between plasma B₁₂ and folate at 9 and 36 months and psychomotor development at 36 months in well-nourished Danish children. Subjects from the SKOT cohorts with B₁₂ measurement and completed Ages and Stages Questionnaire, 3rd edition (ASQ-3) at 36 months were included (n 280). Dietary intake, B₁₂ and folate concentrations were collected at 9 and 36 months, and ASQ-3 was assessed at 36 months. Associations between B₁₂ and folate at 9 and 36 months and ASQ-3 were analysed using regression models. Associations between diet and B₁₂ were also investigated. No children had insufficient B₁₂ (<148 pmol/l) at 36 months. B₁₂ at 36 month was positively associated with total ASQ-3 corresponding to an increase of 100 pmol/l B₁₂ per 1·5 increase in total ASQ-3 score (P = 0·019) which remained significant after adjustment for potential confounders including 9 months values. B₁₂ at 9 months or folate at any time point was not associated with total ASQ-3. Intake of milk products was associated with B₁₂ at 36 months (P = 0·003) and showed a trend at 9 months (P = 0·069). Intake of meat products was not associated with B₁₂. In conclusion, B₁₂ was positively related to psychomotor development at 3 years in well-nourished children, indicating that the impact of having marginally low B₁₂ status on psychomotor development in well-nourished children should be examined further.

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.

Infant Feeding Practices And Childhood Acute Leukemia: Findings From The Childhood Cancer & Leukemia International Consortium

Increasing evidence suggests that breastfeeding may protect from childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). However, most studies have limited their analyses to any breastfeeding, and only a few data have examined exclusive breastfeeding, or other exposures such as formula milk. We performed pooled analyses and individual participant data meta-analyses of data from sixteen studies (N=17,189 controls; N=10,782 ALL and N=1,690 AML cases) from the Childhood Leukemia International Consortium (CLIC) to characterize the associations of breastfeeding duration with ALL and AML, as well as exclusive breastfeeding duration and age at introduction to formula with ALL. In unconditional multivariable logistic regression analyses of pooled data, we observed decreased odds of ALL among children breastfed 4-6 months (0.88, 95% CI 0.81-0.96) or 7-12 months (OR 0.85, 0.79-0.92). We observed a similar inverse association between breastfeeding ≥4 months and AML (0.82, 95% CI 0.71-0.95). Odds of ALL were reduced among children exclusively breastfed 4-6 months (OR 0.73, 95% CI 0.63-0.85) or 7-12 months (OR 0.70, 95% CI 0.53-0.92). Random effects meta-analyses produced similar estimates, and findings were unchanged in sensitivity analyses adjusted for race/ethnicity or mode of delivery, restricted to children diagnosed ≥1 year of age, or diagnosed with B-ALL. Our pooled analyses indicate that longer breastfeeding is associated with decreased odds of ALL and AML. Few risk factors for ALL and AML have been described, therefore our findings highlight the need to promote breastfeeding for leukemia prevention.

The effect of milk and rapeseed protein on growth factors in 7-8 year-old healthy children - A randomized controlled trial

OBJECTIVE

Milk protein may stimulate linear growth through insulin-like growth factor-1 (IGF-1). However, the effect of plant proteins on growth factors is largely unknown. This study assesses the effect of combinations of milk and rapeseed protein versus milk protein alone on growth factors in children.

DESIGN

An exploratory 3-armed randomized, double-blind, controlled trial was conducted in 129 healthy 7-8 year-old Danish children. Children received 35 g milk and rapeseed protein (ratio 54:46 or 30:70) or 35 g milk protein per day for 4 weeks. The primary outcome was difference in IGF-1 changes between intervention groups after 4 weeks. Secondary outcomes included changes in IGF-1 after 1 week and changes in insulin-like growth factor binding protein-3 (IGFBP-3), IGF-1/IGFBP-3, insulin, height, weight and body composition after 1 and 4 weeks. Results were analysed by multiple linear mixed-effect models.

RESULTS

There were no differences in changes of plasma IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3), IGF-1/IGFBP-3 ratio or insulin between groups after 1 or 4 weeks based on 89 complete cases (P > 0.10). IGF-1 increased by 13.7 (95% CI 9.7;17.7) ng/mL and 18.0 (14.0;22.0) ng/mL from baseline to week 1 and 4, respectively, a 16% increase during the intervention. Similarly, insulin increased by 31% (14; 50) and 33% (16; 53) from baseline to week 1 and 4. Fat-free mass index (FFMI) increments were higher with milk alone than rapeseed blends (P < 0.05), coinciding with a trend towards a lower height increment. Body mass index increased within all groups (P < 0.05), mainly due to an increase in FFMI (P < 0.01).

CONCLUSION

There were no differences in changes of growth factors between the combinations of milk and rapeseed protein and milk protein alone in healthy, well-nourished children with a habitual intake of milk. Within groups, growth factors increased considerably. Future studies are needed to investigate how intakes of plant and animal proteins affect childhood 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.

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.

Circulating Insulin-Like Growth Factor-1 Is Positively Associated with Growth and Cognition in 6- to 9-Year-Old Schoolchildren from Ghana

BACKGROUND

Milk intake stimulates linear growth and improves cognition in children from low-income countries. These effects may be mediated through insulin-like growth factor-1 (IGF-1).

OBJECTIVE

The objective was to assess the effect of milk supplement on circulating IGF-1 and to assess IGF-1 as a correlate of growth and cognition in children.

METHODS

Secondary data on blood spot IGF-1 from a randomized, double-blind, controlled trial in 6-9-y-old children from rural Ghana were analyzed. Intervention groups received porridge with non-energy-balanced supplements: 8.8 g milk protein/d, 100 kcal/d (Milk8); 4.4 g milk and 4.4 g rice protein/d, 100 kcal/d (Milk/rice); 4.4 g milk protein/d, 48 kcal/d (Milk4); or a control (no protein, 10 kcal/d). IGF-1, length, body composition, and Cambridge Neuropsychological Test Automated Battery (CANTAB) were measured at 3.5 or 8.5 mo. Linear regressions were used to assess the effect of milk interventions on IGF-1 and IGF-1 as a correlate of growth and cognition.

RESULTS

The increase in IGF-1 was 15.3 (95% CI: 3.3, 27.3) ng/mL higher in children receiving Milk8 compared with the control. The IGF-1 increases in the isonitrogenous, isoenergetic Milk/rice or the Milk4 groups were not different from the control (P ≥ 0.49). The increase in IGF-1 was associated with improvements in 4 out of 5 CANTAB domains. The strongest associations included reductions in "mean correct latency" from Pattern Recognition Memory and "pre-extradimensional (pre-ED) shift errors" from Intra/Extradimensional Set Shift (P ≤ 0.005). In addition, change in IGF-1 was positively associated with changes in height, weight, and fat-free mass (P ≤ 0.001).

CONCLUSIONS

Intake of skimmed milk powder corresponding to one, but not half a glass of milk on school days stimulates IGF-1 in 6-9-y-old Ghanian children. IGF-1 seems to mediate the effect of milk intake on growth and cognition. The association between IGF-1 and cognition in relation to milk intake is novel and opens possibilities for dietary interventions to improve cognition.

The IGF system and longitudinal growth in preterm infants in relation to gestational age, birth weight and gender

OBJECTIVE

Growth factors in the blood of very preterm infants may reflect growth and contribute to the understanding of early development. We investigated postnatal levels of insulin-like growth factors (IGFs) in infants born very preterm and related them to early growth development.

DESIGN

Blood samples were analyzed weekly for IGF-I, IGF-II, IGF binding protein (BP)-1, IGFBP-3, and acid-label subunit (ALS).

METHODS

73 children born very preterm (gestational age (GA) <32 weeks) were divided according to their gender-specific birth weight standard deviation score (SDS) into either appropriate for GA (AGA) or small for GA (SGA). Fifty-two (71%) and forty-three (59%) infants completed follow-up with anthropometry at approximately 3 years and at 5 years of age respectively. Thirty-six subjects (49%) had blood sampling for IGF-I and IGFBP-3 measurements up to 3 years of age.

RESULTS

IGF-I, IGFBP-3, and ALS levels increased in all groups from week 31 to week 36, with generally lower levels in the SGAs, with a concomitant lower growth velocity. Postnatal ALS was strongly associated with IGF-I and IGFBP-3 in boys, girls and AGA infants. IGF-II was higher in earlier born preterms (GA < 27 weeks) at postmenstrual ages 27.5-29.9 weeks compared with SGAs and late GA (GA ≥ 27 weeks) preterms (p < .0001). IGF-II, in contrast to IGF-I, did not differ between SGAs and AGAs at weeks 31-36. Mean IGFBP-1 was highest in the SGAs compared to AGAs at mean week 28,5 and 31 (p = .001) and IGFBP-1 levels were elevated in relation to IGF-I in the SGAs at that period. At follow-up, the increase in IGF-I between week 31 and 33.5 was a significant positive determinant of height SDS at 3 and 5 years of age in forward multiple regression analysis, independent of target height.

CONCLUSION

This is the first study to investigate postnatal ALS levels in preterm infants. In very preterm infants, IGF-II is less affected by size at birth during early postnatal weeks compared with IGF-I. Early elevated IGFBP-1 might protect the SGA infants from an intense metabolic rate. Our results indicate that anabolic and metabolic processes during weeks 31-36 predicts later height.

Modifications of Own Mothers' Milk Fortification Protocol Affect Early Plasma IGF-I and Ghrelin Levels in Preterm Infants. A Randomized Clinical Trial

The aim was to investigate the effect of two own mother’s milk (OMM) fortification protocols on (a) IGF-I and ghrelin plasma levels at 35 post-conceptional weeks (PCW, T2) and whether this effect is maintained after elimination of the differences in OMM fortification, and (b) growth until 12 months corrected age. Forty-eight OMM-fed preterm infants (GA 24–32 weeks) were randomly allocated to the fixed-fortification (FF) group (n = 23) and the protein-targeting fortification (PTF) group (n = 25) targeting the recommended daily protein intake (PI). Plasma IGF-I and ghrelin were assessed at 35 (T2) and 40 (T3) PCW while growth was longitudinally assessed until 12 months corrected age. PTF group had lower IGF-I and higher ghrelin than FF group at T2, while receiving lower daily protein and energy amounts. PI correlated positively to T2-IGF-I and inversely to T3-ghrelin while energy intake (EI) correlated inversely to T2- and T3-ghrelin. Group and PI were independent predictors of adjusted T2-IGF-I, while group and EI were predictors of adjusted and T2-ghrelin. Growth parameter z-scores were comparable between groups up to 12 months corrected age. Modifications of OMM fortification have a transient effect on early plasma IGF-I and ghrelin levels in preterm infants in a way consistent with the previously recognized protein-energy/endocrine balance, indicating a potential programming effect.

Associations of Current, Childhood, and Adolescent Milk Intake with Serum Insulin-like Growth Factor (IGF)-1 and IGF Binding Protein 3 Concentrations in Adulthood

Previous studies have shown that insulin-like growth factor (IGF)-1 levels are positively and IGF binding protein (IGFBP)-3 levels negatively associated with risk of certain cancers. Also, dietary factors may influence the IGF system. We aimed to analyze the associations of current, childhood and adolescent milk intake with IGF-1 levels, IGFBP-3 levels and IGF-1:IGFBP-3 molar ratio in adulthood. Multivariable linear regression analyses by sex and race/ethnicity were performed using cross-sectional data from the Third National Health and Nutrition Examination Survey. A total of 5,805 participants were included in the analyses. Adult IGF-1 levels and IGF-1:IGFBP-3 molar ratio had significant inverse associations (P-trend = 0.02) with adolescent milk intake in non-Hispanic white men, but not in men of other race/ethnicities or in women. There were no associations between current or childhood milk intake and IGF-1 levels or IGF-1:IGFBP-3 molar ratio in adulthood. Current milk intake and childhood milk intake had significant positive associations (P-trend = 0.02) with adult IGFBP-3 levels in non-Hispanic white and non-Hispanic black women, respectively, but no associations were observed in Mexican American women or in men. Overall, there were long-term and short-term associations between milk intake and IGF-1 and IGFBP-3 levels, but the associations varied by race/ethnicity and sex.

Growth and protein-rich food intake in infancy is associated with fat-free mass index at 2-3 years of age

AIM

The reduction of infant protein intake and associated growth velocity is a recommended public health strategy for reducing the risk of childhood obesity. This study tests the hypothesis that infants' growth and protein-rich food (dairy, meat, fish and egg) intake influences childhood body size and composition at 2-3 years of age.

METHODS

Thirty-six children were studied from the Feeding Queensland Babies Study Cohort, which prospectively collected data on infant growth and diet. Body composition was estimated using the deuterium oxide dilution technique at 2-3 years of age.

RESULTS

Fat-free mass index Z score at 2-3 years of age was positively associated with animal protein food (dairy, meat, fish and egg) intake at 12 months of age (r = 0.58, P = 0.002, false discovery rate corrected P value = 0.008) and negatively associated with weight-for-length growth velocity from 6 to 12 months of age (r = -0.75, P = 0.019, false discovery rate corrected P value = 0.038), which in turn was negatively associated with growth velocity from 0 to 6 months of age (r = -0.790, P = 0.007).

CONCLUSION

This study suggests that strategies to reduce protein intake and growth velocity in early life may limit fat-free mass growth, potentially predisposing to increased adiposity in later life.

The Influence of Maternal Obesity and Breastfeeding on Infant Appetite- and Growth-Related Hormone Concentrations: The SKOT Cohort Studies

BACKGROUND/AIMS

Exposure to obesity during pregnancy may lead to adverse changes in the offspring's metabolic profile. We compared appetite- and growth-related hormones in a cohort of infants born to obese mothers (SKOT-II) with infants born mainly to nonobese mothers (SKOT-I).

METHODS

Infants from SKOT-I (n = 273) and SKOT-II (n = 132) were examined including anthropometric measurements and blood samples analyzed for glucose, insulin, insulin-like growth factor-I (IGF-I), adiponectin, and leptin. Information on breastfeeding and parental characteristics were also collected.

RESULTS

At 9 months of age, SKOT-II infants were 3.6% heavier and 1.2% longer than SKOT-I infants even though their mothers were shorter. There was no difference in body mass index (BMI). SKOT-II infants had higher levels of insulin, adiponectin, and leptin but lower levels of IGF-I compared to SKOT-I infants (all p ≤ 0.015). These differences remained, except for leptin, when adjusted for current weight. Breastfeeding versus nonbreastfeeding at 9 months was associated with lower concentrations of all hormones (all p ≤ 0.003). In adjusted models, maternal BMI at 9 months was positively associated with insulin and adiponectin and negatively with IGF-I.

CONCLUSIONS

Pre-pregnancy obesity confers symmetrically larger infant body size and higher levels of most growth- and appetite-related hormones but surprisingly lower levels of IGF-I, suggesting other possible infant growth-promoting effects through insulin.

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.

Early Adiposity Rebound and Premature Adrenarche

OBJECTIVES

To examine differences in the growth pattern and the age at adiposity rebound (AR) between children with premature adrenarche (PA) and their healthy peers (controls).

STUDY DESIGN

In this cross-sectional study of 82 prepubertal children with PA and 63 controls, the main outcome measures were height and body mass index SDS progression, from birth to presentation at the clinic, baseline biochemical and hormonal evaluation, bone age determination, and age at AR.

RESULTS

Children with PA were significantly taller and more adipose than controls from the first years of life. 33% of children with PA presented the growth pattern of constitutional advancement of growth (ie, early growth acceleration) vs 19% of controls (P = .045). Children with PA had an earlier AR compared with controls; mean age at AR in girls with PA was 3.73 (1.03) years vs 4.93 (1.36) years for control girls (P = .001) and in boys with PA was 3.45 (0.73) vs 5.10 (1.50) years in control boys (P = .048). Both obese and nonobese girls with PA were taller and had earlier age at AR compared with nonobese controls.

CONCLUSIONS

Early AR and constitutional advancement of growth may be triggering factors for adrenal androgen production and PA.

Dietary protein intake and quality in early life: impact on growth and obesity

PURPOSE OF REVIEW

Obesity is an increasing problem and high-protein intake early in life seems to increase later risk of obesity. This review summarizes recent publications in the area including observational and intervention studies and publications on underlying mechanisms.

RECENT FINDINGS

Recent observational and randomized controlled trials confirmed that high-protein intake in early life seems to increase early weight gain and the risk of later overweight and obesity. Recent studies have looked at the effect of different sources of protein, and especially high-animal protein intake seems to have an effect on obesity. Specific amino acids, such as leucine, have also been implicated in increasing later obesity risk maybe via specific actions on insulin-like growth factor I. Furthermore, additional underlying mechanisms including epigenetics have been linked to long-term obesogenic programming. Finally, infants with catch-up growth or specific genotypes might be particularly vulnerable to high-protein intake.

SUMMARY

Recent studies confirm the associations between high-protein intake during the first 2 years and later obesity. Furthermore, knowledge of the mechanisms involved and the role of different dietary protein sources and amino acids has increased, but intervention studies are needed to confirm the mechanisms. Avoiding high-protein intake in early life holds promise as a preventive strategy for childhood obesity.