Abstract
The first 1000 days, running from conception to two-years of age, is well established as a critical window for growth, within which growth failure results in stunting and a range of associated health issues. It is also recognised as an important period for the programming of later disease risk. Low birth weight (LBW) - a marker of intrauterine growth restriction - has long been implicated as a predictor of later cardiometabolic susceptibility. More recently, early postnatal growth has been identified as playing an important role in this association. In particular, it seems that a combination of being born small and undergoing infant ‘catch-up growth’ predisposes to adverse adult metabolic outcomes.The precise pathways of, and mechanisms underpinning, these associations remain unclear. Studies making use of increasingly sophisticated methods of infant body composition assessment suggest programming of adiposity within the developmentally plastic first 1000 days to represent a plausible mediating link.
Use of sophisticated methods for body composition assessment is still, however, limited in low- and middle-income country settings facing a burgeoning ‘double burden of malnutrition’ (DBM). The DBM is characterised by increasing adult overweight, obesity, and associated non-communicable diseases alongside persistently high rates of LBW and early growth faltering, manifested in stunting and wasting. Data are needed to inform strategies aiming to ensure adequate early growth whilst preventing later metabolic risk.
The research presented in this thesis utilised data collected from two cohorts in The Gambia, West Africa. The first - the ‘HERO-G’ study - was a sample of mothers and infants residing in a rural subsistence agricultural community. The second - The ‘MILQ’ study - was a cohort of urban based, well-nourished mothers and infants. Both studies involved the collection of maternal anthropometry in pregnancy, detailed infant anthropometry at delivery, and repeated postnatal anthropometric and body composition assessment, by Air Displacement Plethysmography (ADP).
First, the relationship was assessed between pre-conceptional (maternal pre-pregnancy BMI) and gestational (weight gain) determinants of infant size and body composition at birth and three months. Second, body composition in infancy, as assessed by ADP, was characterised and previously proposed anthropometric equations for the estimation of infant fat mass were validated against the ADP-derived data. Third, associations between statistically independent ‘conditional’ measures of weight and length gain within discrete windows of infancy and body composition at two years were assessed. Finally, growth and accompanying body composition of the two cohorts was compared in order to assess whether different patterns of growth between the two cohorts were apparent, and whether any such differences were accompanied by differences in infant body composition.
Together, using data from two contrasting Gambian cohorts, the work presented in this Thesis draws novel insights into relationships between nutrition, growth, and body composition within the developmentally important first 1000 days. The findings are a particularly valuable contribution to the literature in that they are from a West African setting where data in this field is scarce.
Date of Award | 1 Aug 2023 |
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Original language | English |
Awarding Institution |
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Supervisor | Sophie Moore (Supervisor) & Kennedy Cruickshank (Supervisor) |