Determinants of Infant Adiposity across the First 6 Months of Life: Evidence from the Baby-bod study.

Manoja P Herath,Sisitha Jayasinghe,Kiran D K Ahuja,Andrew P Hills,Nuala M Byrne,Jeffrey M Beckett

doi:10.3390/jcm10081770

Abstract

Excess adiposity in infancy may predispose individuals to obesity later in life. The literature on determinants of adiposity in infants is equivocal. In this longitudinal cohort study, we investigated pre-pregnancy, prenatal and postnatal determinants of different adiposity indices in infants, i.e., fat mass (FM), percent FM (%FM), fat mass index (FMI) and log-log index (FM/FFMp), from birth to 6 months, using linear mixed-effects regression. Body composition was measured in 322, 174 and 109 infants at birth and 3 and 6 months afterwards, respectively, utilising air displacement plethysmography. Positive associations were observed between gestation length and infant FM, maternal self-reported pre-pregnancy body mass index and infant %FM, and parity and infant %FM and FMI at birth. Surprisingly, maternal intake of iron supplements during pregnancy was associated with infant FM, %FM and FMI at 3 months and FM/FFMp at 6 months. Male infant sex and formula feeding were negatively associated with all adiposity indices at 6 months. In conclusion, pre-pregnancy and pregnancy factors influence adiposity during early life, and any unfavourable impacts may be modulated postnatally via infant feeding practices. Moreover, as these associations are dependent on the adiposity indices used, it is crucial that researchers use conceptually and statistically robust approaches such as FM/FFMp.

Highlights

The prevalence of obesity and comorbidities are rising at alarming rates across all age groups worldwide [1]
Bold values denote statistical significance at p < 0.05. In this longitudinal cohort study, we explored associations between pre-pregnancy, prenatal and postnatal factors and infant adiposity measured with four indices—namely, fat mass (FM), %FM, fat mass index (FMI) and FM/FFMp, across 0–6 months of age
In our systematic review and meta-analysis of studies comparing adiposity in infants born to mothers with gestational diabetes mellitus (GDM) and mothers with normal glucose tolerance, we have shown that, despite treatments for GDM, infants exposed to GDM in utero had higher total body adiposity than the infants born to mothers with normal glucose tolerance [34]

Summary

Introduction

The prevalence of obesity and comorbidities are rising at alarming rates across all age groups worldwide [1]. Programming of the growth trajectory in humans occurs during the first 1000 days of life (from conception to 2 years of age), when developmental plasticity is at its maximum [3] Across this critical period, insults or inappropriate stimuli can result in metabolic and structural alterations in cells, organs and systems that may be irreversible [4]. As associations between maternal factors and adiposity at birth have been reported to change over the first 5 months of life [6], studying the combined effect of a range of pre-pregnancy, prenatal and postnatal factors throughout infancy could provide a better understanding of the modulation of adiposity accretion during this critical period

Methods

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Discussion

Conclusion