Early-life determinants of childhood plasma insulin levels: implications for primordial prevention of diabetes

Causal effects of time-varying body size on selected autoimmune disorders: a life course Mendelian randomisation study

BACKGROUND

Based on Barker's hypothesis, some studies investigated the associations between birth weight and several disorders. Apart from issues with statistical power and well-known shortcomings of the observational study design, there are no studies accounting for changes in weight-related body size over the life course regarding rheumatoid arthritis, psoriasis, psoriatic arthritis and multiple sclerosis.

METHODS

Using genetic information of up to 806 834 participants, this study investigated the associations between time-varying weight-related body size from birth to adulthood and the mentioned autoimmune diseases. Performing Mendelian randomisation (MR), the radial inverse-variance weighted approach was used iteratively in primary analyses. Robustness of the results was confirmed in several sensitivity analyses. Potential time-dependent mediation mechanisms were identified through network-clustering and assessed using multivariable MR.

RESULTS

Genetically predicted birth weight (fetal effect) was positively associated with rheumatoid arthritis (OR 1.44; 95% CI 1.17 to 1.77; Padj =0.005) but not with psoriasis, psoriatic arthritis or multiple sclerosis. This association was found to be mediated by body mass index (BMI) in adulthood (OR 1.45; 95% CI 1.14 to 1.84; Padj =0.019) rather than childhood. The direct effect of birth weight attenuated (OR 1.19; 95% CI 0.88 to 1.62); Padj =1) after adjustment for time-varying BMI.

CONCLUSION

Increased birth weight appears to be a risk factor for later manifestation of rheumatoid arthritis due to both fetal genetic components and high BMI persisting into adulthood. Approaches to prevent and minimise the risk of rheumatoid arthritis could include preventing obesity in adults with high birth weight.

Longitudinal Trajectory and Early Life Determinant of Childhood Adipokines: Findings From a Racially Diverse Birth Cohort

CONTEXT

Leptin and adiponectin play important roles in systemic metabolic homeostasis, beginning in utero. Limited data exist on the levels and trajectories of these 2 hormones at birth and in childhood and their biological and social determinants.

OBJECTIVE

We examined the longitudinal trajectories of leptin and adiponectin from birth to early childhood, along with influential prenatal and infancy factors, and whether the trajectories and risk factors differ by preterm birth status.

METHODS

We included mother-infant pairs in the Boston Birth Cohort, a predominantly Black, indigenous, and people of color (BIPOC) study population. We measured infant plasma leptin and adiponectin levels at birth and in early childhood. We examined longitudinal trajectories and the associated prenatal maternal and infancy factors. We analyzed 716 infants (158 preterm) who had leptin and adiponectin measured at birth and in early childhood (mean corrected age 2.18 years [interquartile range, 0.4-10.4]).

RESULTS

Cord leptin was higher in term infants (40 230 vs 20 481 in preterm, P < 0.0001) but childhood leptin did not differ by prematurity (4123 in term vs 4181 in preterm, P = 0.92). Adiponectin was higher in term infants at birth (18 416 vs 11 223, P < 0.0001) and in childhood (12 108 vs 10532, P = 0.04). In stepwise regression, Black race was associated with higher childhood leptin and lower childhood adiponectin. Female sex was associated with higher childhood leptin levels and lower childhood adiponectin levels in multivariable regression models.

CONCLUSION

Our results highlight preterm status, race, and biological sex as predictors of adipokine trajectory throughout childhood. These findings raise the possibility that early life programming of adipokines may contribute to higher metabolic risk in life, especially among Black children born preterm.

Maternal and fetal factors affecting cord plasma leptin and adiponectin levels and their ratio in preterm and term newborns: New insight on fetal origins of metabolic dysfunction

Background

Understanding of maternal and fetal factors affecting leptin, adiponectin, and adiponectin:leptin ratio at birth may provide valuable insights into potential future risk of metabolic alterations and inform primordial prevention and precision nutrition strategies. The objective of this study is to identify maternal and fetal risk factors that affect leptin and adiponectin levels (markers of adiposity) and adiponectin/leptin ratio (a marker of dysfunctional adipose tissue) at birth.

Methods

We studied mother-infant pairs in the Boston Birth Cohort. Cord blood was collected at birth. We used student t- tests to compare log normalized cord leptin and adiponectin levels. Regression analysis was performed to examine the association of maternal and fetal factors with leptin and adiponectin levels and adiponectin:leptin ratio at birth in both term and preterm infants.

Results

We analyzed 1012 infants (245 preterm). Both cord leptin and adiponectin were higher in term infants than preterm infants (10.2 ± 0.9 vs. 9.2 ± 1.3, P < 0.0001 and 9.5 ± 0.7 vs. 8.9 ± 0.8, P < 0.0001, respectively). Cord leptin was higher for Black infants (10.1 ± 1.1 vs. 9.9 ± 1.2; P < 0.001) although Black (ref: non-Black) infants had lower cord adiponectin levels (9.3 ± 0.8 vs. 9.5 ± 0.7; P = 0.01). Ratio of adiponectin to leptin (log normalized) was higher in preterm infants (-0.24) vs. term infants (-0.69). On regression analysis, cord leptin was positively associated with longer gestational age (GA), birth weight z score, Black race, maternal overweight and obesity, gestational diabetes and pregestational diabetes mellitus and negatively associated with male sex. Cord adiponectin was positively associated with GA, birth weight z score and negatively with Black race and male sex. Adiponectin:leptin ratio was positively with male sex and negatively with GA, birth weight z score, Black race, gestational DM, pregestational DM and maternal overweight and obesity.

Conclusions

We identified several factors that affect leptin and adiponectin levels along with adiponectin-leptin ratio at birth beyond GA and birth weight which could also play an important role in influencing the trajectory of these hormones and future cardiometabolic outcomes. This knowledge can help tailor precision nutrition interventions.