Newborn adipokines and early childhood growth

Estimated exposure to perfluoroalkyl substances during infancy and serum-adipokine concentrations in later childhood

BACKGROUND

Perfluoroalkyl substances (PFASs) are transferred through human milk and may cause elevated exposure during infancy. Given the lack of early postnatal blood samples, PFAS concentrations can be estimated to serve as predictors of subsequent metabolic toxicity.

METHODS

A total of 298 children from a prospective birth cohort were followed up through to age 9 years. Serum-PFAS was measured at birth and 18 months of age, while exposures during infancy were estimated by structural equations. Adiponectin, resistin, leptin, and the leptin receptor were measured in serum at age 9. Adjusted regression coefficients for estimated serum-PFAS concentrations were calculated, with additional consideration of the duration of breastfeeding and potential effect modification by sex.

RESULTS

A doubling in estimated serum-PFAS concentrations, particularly at ages 6 and 12 months, was associated with a loss of about 10-15% in age 9 resistin concentrations, while other associations were much weaker. Sex dependence of the associations was not observed, and neither did the duration of breastfeeding affect outcomes at age 9.

CONCLUSION

Lowered serum-resistin concentrations at age 9 years were most strongly associated with early postnatal PFAS exposures. These findings suggest that infancy may represent a vulnerable time window for some aspects of metabolic programming that may be affected by PFAS exposure.

IMPACT

Serum-PFAS concentrations during infancy can be estimated in the absence of blood samples. Adipokine concentrations were measured at age 9 years as metabolic biomarkers. Resistin was significantly lower in children with elevated PFAS exposures in infancy. The findings suggest that early postnatal PFAS exposures may affect subsequent metabolic health. Assessment of infancy vulnerability to PFAS can be explored using estimated serum-PFAS concentrations.

Cord blood leptin level and a common variant of its receptor as determinants of the BMI trajectory: The EDEN mother-child cohort

BACKGROUND

Cord blood leptin is an indicator of neonatal fat mass and could shape postnatal adiposity trajectories. Investigating genetic polymorphisms of the leptin receptor gene (LEPR) could help understand the mechanisms involved.

OBJECTIVES

We aimed to investigate the association of cord blood leptin level and the LEPR rs9436303 polymorphism, with body mass index (BMI) at adiposity peak (AP) and age at adiposity rebound (AR).

METHODS

In the EDEN cohort, BMI at AP and age at AR were estimated with polynomial mixed models, for 1713 and 1415 children, respectively. Multivariable linear regression models allowed for examining the associations of cord blood leptin level and LEPR rs9436303 genotype with BMI at AP and age at AR adjusted for potential confounders including birth size groups. We also tested interactions between cord blood leptin level and rs9436303 genotype.

RESULTS

Increased leptin level was associated with reduced BMI at AP and early age at AR (comparing the highest quintile of leptin level to the others). Rs9436303 G-allele carriage was associated with increased BMI at AP and later age at AR but did not modulate the association with leptin level.

CONCLUSION

These results illustrate the role of early life body composition and the intrauterine environment in the programming of adiposity in childhood.

Cord blood adiponectin and leptin are associated with a lower risk of stunting during infancy

Undernutrition is responsible for up to 45% of deaths in children under five, with low- and middle-income countries disproportionately affected. Adipokines are known modulators of metabolism and have been linked to growth rates and neurocognition during infancy. We examined the relationship(s) between cord blood adiponectin and leptin and both longitudinal growth and cognition during the first year of life using generalized estimating equations. Infants were classified as underweight (weight-for-age z-score [WAZ]), stunted (height-for-age z-score [HAZ]) or wasted (weight-for-height z-score [WHZ]) using WHOAnthro software. Cord blood adiponectin and leptin levels were highly correlated (r = 0.35, P < 0.0001) and positively associated with birth WAZ (r = 0.34 and r = 0.45, P < 0.0001, respectively). Adipokines were independently, inversely associated with weight gain. Infants in the highest quintile of adipokine production had a lower risk of being stunted, while neither was associated with lower WAZ or WHZ in final adjusted models. Cognition was not found to be independently related to cord blood leptin or adiponectin. The negative association with adipokines and rate of weight gain during infancy may reflect heightened nutritional status at birth rather than a direct hormonal influence. The relationship between leptin or adiponectin and longitudinal length gains suggests that both adipokines may promote linear growth during infancy.

Maternal diet quality during pregnancy is associated with biomarkers of metabolic risk among male offspring

AIMS/HYPOTHESIS

Limited data exist on the association between maternal diet quality during pregnancy and metabolic traits in offspring during early childhood, which is a sensitive period for risk of obesity-related disorders later in life. We aimed to examine the association of maternal diet quality, as indicated by the Healthy Eating Index-2010 (HEI), in pregnancy with offspring metabolic biomarkers and body composition at age 4-7 years.

METHODS

We used data from 761 mother-offspring pairs from the Healthy Start study to examine sex-specific associations of HEI >57 vs ≤57 with offspring fasting glucose, leptin, cholesterol, HDL, LDL, percentage fat mass, BMI z score and log-transformed insulin, 1/insulin, HOMA-IR, adiponectin, triacylglycerols, triacylglycerols:HDL, fat mass, and sum of skinfolds. Multivariable linear regression models accounted for maternal race/ethnicity, age, education, smoking habits during pregnancy and physical activity, and child's age.

RESULTS

During pregnancy, mean (SD) HEI score was 55.0 (13.3), and 43.0% had an HEI score >57. Among boys, there was an inverse association of maternal HEI with offspring glucose, insulin, HOMA-IR and adiponectin. For instance, maternal HEI >57 was associated with lower fasting glucose (-0.11; 95% CI -0.20, -0.02 mmol/l), and lower concentrations of: insulin by 15.3% (95% CI -24.6, -5.0), HOMA-IR by 16.3% (95% CI -25.7, -5.6) and adiponectin by 9.3% (95% CI -16.1, -2.0). Among girls, there was an inverse association of maternal HEI with insulin and a positive association with LDL. However, following covariate adjustment, all estimates among girls were attenuated to the null.

CONCLUSIONS/INTERPRETATION

Greater compliance with the USA Dietary Guidelines via the HEI may improve the maternal-fetal milieu and decrease susceptibility for poor metabolic health among offspring, particularly boys. Future studies are warranted to confirm these associations and determine the underlying mechanisms.

The effect of umbilical cord blood spexin, free 25(OH) vitamin D3 and adipocytokine levels on intrauterine growth and anthropometric measurements in newborns

Spexin is a newly described peptide and is known to reduce the uptake of long-chain fatty acids into adipocytes. The serum spexin levels of obese children between the ages of 12-18 are lower. The effect of serum spexin and free 25(OH) vitamin D3 levels on intrauterine development in newborns is unknown. Our aims is to evaluate the effects of spexin and adipocytokin levels in the cord blood of term newborn babies on the weight of the baby according to the gestation age (GA) and anthropometric measurement results. Babies who were born in our hospital and whose GA was ≥37 weeks were evaluated in three groups as appropriate for GA (AGA), small for GA (SGA) and large for GA (LGA). A total of 84 babies, including an equal number of infants in AGA, SGA and LGA groups, were included in the study. Spexin, leptin, active ghrelin, free 25(OH) vitamin D3, glucose, and insulin levels in the cord blood of infants were examined at birth. The results were compared according to GA and birth weight (BW). There was no statistically significant difference between groups in terms of mean spexin, active ghrelin, free 25(OH) vitamin D3, and insulin levels. The mean leptin level was significantly higher in LGA group than SGA and AGA groups (p 0.004). The mean spexin and leptin levels were higher in girls than in boys (respectively p value 0.029, 0.003). Although there is a significant positive correlation between BW, head circumference, height, umbilical circumference, umbilical circumference/height ratio and the mean leptin levels (p < 0.001), there was no significant correlation between mean spexin, active ghrelin, free 25 (OH) vitamin D3, insulin, and glucose levels. This study suggests that spexin may not have an effect on intrauterine development.

Appetite-regulating hormone trajectories and relationships with fat mass development in term-born infants during the first 6 months of life

Background

The first 6 months of life are a critical window for adiposity programming. Appetite-regulating hormones (ARH) are involved in food intake regulation and might, therefore, play a role in adiposity programming. Studies examining ARH in early life are limited.

Purpose

To investigate ghrelin, peptide YY (PYY) and leptin until 6 months and associations with fat mass percentage (FM%), infant feeding and human milk macronutrients.

Procedures

In 297 term-born infants (Sophia Pluto Cohort), ghrelin (acylated), PYY and leptin were determined at 3 and 6 months, with FM% measurement by PEAPOD. Exclusive breastfeeding (BF) was classified as BF ≥ 3 months. Human milk macronutrients were analyzed (MIRIS Human Milk Analyzer).

Main findings

Ghrelin increased from 3 to 6 months (p < 0.001), while PYY decreased (p < 0.001), resulting in increasing ghrelin/PYY ratio. Leptin decreased. Leptin at 3 months was higher in girls, other ARH were similar between sexes. Leptin at 3 and 6 months correlated with FM% at both ages(R ≥ 0.321, p ≤ 0.001) and gain in FM% from 1 to 6 months(R ≥ 0.204, p = 0.001). In BF infants, also ghrelin and ghrelin/PYY ratio correlated with this gain in FM%. Exclusively BF infants had lower ghrelin and higher PYY compared to formula fed infants at 3 months (p ≤ 0.039). ARH did not correlate with macronutrients.

Conclusions

Increasing ghrelin and decreasing PYY, thus increasing ghrelin/PYY ratio, suggests an increasing orexigenic drive until 6 months. ARH were different between BF and FF infants at 3 months, but did not correlate with human milk macronutrients. Ghrelin and leptin, but not PYY, correlated with more FM development during the first 6 months, suggesting that they might be involved in adiposity programming.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02533-z.

Does cord blood leptin level mediate the association between neonatal body size and postnatal growth? Results from the EDEN mother-child cohort study

Background: Leptin is potentially involved in the correction of early postnatal growth of infants having deviated from their genetic trajectory in utero.Aim: To analyse the potential mediating role of cord blood leptin level in the association between neonatal anthropometry and early postnatal growth in the mother-child EDEN cohort.Subjects and methods: We included term newborns with information on leptin, birth weight and length, and weight and length SD-score changes over the first 2 months. The Baron and Kenny method was used to quantify the mediation contribution of leptin in the association between neonatal anthropometry and postnatal growth, considering several confounders. Analyses were stratified to consider sexual dimorphism.Results: A 1 SD higher birth weight was associated with a lower 2-months weight variation of 0.27 (0.18; 0.36) SD and a 0.16 (0.06; 0.26) SD, in boys and girls, respectively. Leptin explained 20% and 25% of these associations, respectively. Leptin did not mediate the association between birth length and birth-to-2 months length variation.Conclusion: Our results suggest that cord blood leptin may not be involved in the negative association between birth length and postnatal length growth but may play a modest mediating role in early postnatal catch-up or catch-down in weight.

An examination of sex differences in associations between cord blood adipokines and childhood adiposity

BACKGROUND

Though the physiological roles of adipokines in metabolism, insulin resistance and satiety are clear, literature regarding associations between cord blood adipokine levels and childhood adiposity is equivocal.

OBJECTIVES

To determine whether cord blood levels of leptin and adiponectin are associated with adiposity in children 2 to 5 years of age, and whether such associations are modified by sex.

METHODS

Leptin and adiponectin levels were measured in cord blood and anthropometric measures were completed on 550 children enrolled in the Maternal-Infant Research on Environmental Chemicals Child Development Plus study (MIREC-CD Plus). We used multivariable linear and Poisson regression models to determine associations between cord blood adipokine levels and child body mass index (BMI), triceps and subscapular skinfold thickness and risk of overweight/obesity and to assess effect modification by child sex.

RESULTS

Cord blood adiponectin was significantly associated with modest increases in BMI and the sum of triceps and subscapular skinfold z-scores in boys but not girls. A doubling of adiponectin levels was associated with a 30% increased risk of overweight/obesity in boys (RR = 1.30; 95% CI: 1.02, 1.64). Leptin was not associated with anthropometric measures in either sex.

CONCLUSIONS

The observed associations between adiponectin and adiposity in boys were statistically significant, of moderate magnitude, and underscore the value of considering sex-specific patterns.

Mediation Analysis Supports a Causal Relationship between Maternal Hyperglycemia and Placental DNA Methylation Variations at the Leptin Gene Locus and Cord Blood Leptin Levels

Changes in fetal DNA methylation (DNAm) of the leptin (LEP) gene have been associated with exposure to maternal hyperglycemia, but their links with childhood obesity risk are still unclear. We investigated the association between maternal hyperglycemia, placental LEP DNAm (25 5′-C-phosphate-G-3′ (CpG) sites), neonatal leptinemia, and adiposity (i.e., BMI and skinfold thickness (ST) (subscapular (SS) + triceps (TR) skinfold measures, and the ratio of SS:TR) at 3-years-old, in 259 mother–child dyads, from Gen3G birth cohort. We conducted multivariate linear analyses adjusted for gestational age at birth, sex of the child, age at follow-up, and cellular heterogeneity. We assessed the causal role of DNAm in the association between maternal glycemia and childhood outcomes, using mediation analysis. We found three CpGs associated with neonatal leptinemia (p ≤ 0.002). Of these, cg05136031 and cg15758240 were also associated with BMI (β = −2.69, p = 0.05) and fat distribution (β = −0.581, p = 0.05) at 3-years-old, respectively. Maternal glycemia was associated with DNAm at cg15758240 (β = −0.01, p = 0.04) and neonatal leptinemia (β = 0.19, p = 0.004). DNAm levels at cg15758240 mediates 0.8% of the association between maternal glycemia and neonatal leptinemia (p < 0.001). Our results support that DNAm regulation of the leptin pathway in response to maternal glycemia might be involved in programming adiposity in childhood.

Penalized regression models to select biomarkers of environmental enteric dysfunction associated with linear growth acquisition in a Peruvian birth cohort

Environmental enteric dysfunction (EED) is associated with chronic undernutrition. Efforts to identify minimally invasive biomarkers of EED reveal an expanding number of candidate analytes. An analytic strategy is reported to select among candidate biomarkers and systematically express the strength of each marker’s association with linear growth in infancy and early childhood. 180 analytes were quantified in fecal, urine and plasma samples taken at 7, 15 and 24 months of age from 258 subjects in a birth cohort in Peru. Treating the subjects’ length-for-age Z-score (LAZ-score) over a 2-month lag as the outcome, penalized linear regression models with different shrinkage methods were fitted to determine the best-fitting subset. These were then included with covariates in linear regression models to obtain estimates of each biomarker’s adjusted effect on growth. Transferrin had the largest and most statistically significant adjusted effect on short-term linear growth as measured by LAZ-score–a coefficient value of 0.50 (0.24, 0.75) for each log₂ increase in plasma transferrin concentration. Other biomarkers with large effect size estimates included adiponectin, arginine, growth hormone, proline and serum amyloid P-component. The selected subset explained up to 23.0% of the variability in LAZ-score. Penalized regression modeling approaches can be used to select subsets from large panels of candidate biomarkers of EED. There is a need to systematically express the strength of association of biomarkers with linear growth or other outcomes to compare results across studies.

Childhood undernutrition is widespread throughout the world and has severe, long-lasting health impacts. Substances measured in blood, urine and stool could be used as biomarkers to identify children undergoing growth failure before these impacts occur. However, it is not yet known which of the many markers that can be identified are accurate and clinically useful predictors of poor growth in infants and children. This study used a large number of candidate biomarkers of immune activation, metabolism and hormones and applied statistical methods to narrow them down from 110 different substances, to the 36 best predictors of growth in 258 Peruvian infants. It also estimated how large the effect of each of these markers was on height two months later. The biomarker with the largest effect was transferrin, a glycoprotein that can be measured in blood samples. 15-month old children with elevated transferrin were around two thirds of a centimeter taller on average at 17 months than those with low levels. Transferrin and other proteins, glycoproteins, hormones and antibodies that this study identified, can be measured easily and affordably in standard laboratories making them feasible to be used broadly as prognostic markers as part of child health and nutrition programs in under-resourced settings.

Early Life Exposures to Perfluoroalkyl Substances in Relation to Adipokine Hormone Levels at Birth and During Childhood

BACKGROUND

Birth cohort studies have linked exposure to perfluoroalkyl substances (PFASs) with child anthropometry. Metabolic hormone dysregulation needs to be considered as a potential adverse outcome pathway. We examined the associations between PFAS exposures and concentrations of adipokine hormones from birth to adolescence.

METHODS

We studied 80 mother-child pairs from a Faroese cohort born in 1997 to 2000. Five PFASs were measured in maternal pregnancy serum and in child serum at ages 5, 7, and 13 years. Leptin, adiponectin, and resistin were analyzed in cord serum and child serum at the same ages. We fitted multivariable-adjusted generalized estimating equations to assess the associations of PFASs at each age with repeated adipokine concentrations at concurrent and subsequent ages.

RESULTS

We observed tendencies of inverse associations between PFASs and adipokine hormones specific to particular ages and sex. Significant associations with all adipokines were observed for maternal and child 5-year serum PFAS concentrations, whereas associations for PFASs measured at ages 7 to 13 years were mostly null. The inverse associations with leptin and adiponectin were seen mainly in females, whereas the inverse PFAS associations with resistin levels were seen mainly in males. Estimates for significant associations (P value <0.05) suggested mean decreases in hormone levels (range) by 38% to 89% for leptin, 16% to 70% for adiponectin, and 33% to 62% for resistin for each twofold increase in serum PFAS concentration.

CONCLUSIONS

These findings suggest adipokine hormone dysregulation in early life as a potential pathway underlying PFAS-related health outcomes and underscore the need to further account for susceptibility windows and sex-dimorphic effects in future investigations.

Neonatal Adipocytokines and Longitudinal Patterns of Childhood Growth

OBJECTIVE

Adipocytokines are markers of fetal metabolism, but their association with childhood growth is unclear. This study examined associations of neonatal adipocytokines with longitudinal childhood adiposity measures in a prospective cohort of pregnant women and their children.

METHODS

Leptin and adiponectin concentrations at delivery and children's BMI z scores between age 4 weeks and 8 years were measured. Differences in BMI z scores and rates of BMI z score change by leptin (n = 257) and adiponectin (n = 271) terciles were estimated.

RESULTS

Children in the middle (mean difference: 0.2; 95% CI: -0.1 to 0.4) and highest (0.4; 95% CI: 0.1 to 0.6) leptin terciles had greater BMI z scores than children in the lowest tercile. Associations were null after adjustment for birth weight z score. Children in the lowest adiponectin tercile had greater gains in BMI z score (change per year: 0.10; 95% CI: 0.08 to 0.13) than children in the middle (0.07; 95% CI: 0.04 to 0.09) and highest terciles (0.04; 95% CI: -0.01 to 0.05) (adiponectin × age interaction P < 0.001).

CONCLUSIONS

Lower adiponectin levels were associated with increased rates of BMI gains in the first 8 years of life. Though leptin was positively associated with BMI, this association may be confounded by birth weight.

An Update on the Emerging Role of Resistin on the Pathogenesis of Osteoarthritis

Background

Resistin may be involved in the pathogenesis of osteoarthritis (OA), but a systematic understanding of the role of resistin in OA is lacking.

Methods

We reviewed studies that evaluated the role of resistin in OA. The expression levels of resistin in vitro experiments and OA/rheumatoid arthritis (RA) patients were analyzed. We also studied potential resistin receptors and the signaling pathways that these receptors activate, ultimately leading to cartilage degeneration.

Results

Resistin levels in both the serum and synovial fluid were higher in OA and RA patients than in healthy subjects. Overall, resistin levels are much higher in serum than in synovial fluid. In human cartilage, resistin induces the expression of proinflammatory factors such as degradative enzymes, leading to the inhibition of cartilage matrix synthesis, perhaps by binding to Toll-like receptor 4 and the adenylyl cyclase-associated protein 1 receptor, which then activates the p38-mitogen-activated phosphate kinase, protein kinase A–cyclic AMP, nuclear factor-κB, and C/enhancer-binding protein β signaling pathways.

Conclusion

Resistin levels are higher in OA patients than in healthy controls; however, the precise role of resistin in the pathogenesis of OA needs to be studied further. Resistin may be a novel therapeutic target in OA in the future.