Early nutrition and eczema in infancy

Eczema prevalence rates among Irish infants are unreported, despite eczema being the most common inflammatory condition of infancy. Maternal and infant nutritional status including vitamin D and other fat-soluble vitamins as well as early infant feeding have been linked with eczema initiation and development. Therefore, early nutrition could be a potential modifiable risk factor. The objective of this thesis was to prospectively describe early infant feeding and complementary feeding practices, to evaluate infant vitamin D supplementation practice, to quantify cord serum 25-hydroxyvitamin D [25(OH)D] and propose reference intervals for vitamin D metabolites, to report eczema prevalence and explore the potential role of infant nutrition and eczema. These research needs were investigated through the Cork BASELINE (Babies After SCOPE: Evaluating the Longitudinal Impact with Neurological and Nutritional Endpoints) Birth Cohort Study (n 2137). This thesis was the first comprehensive report from the birth cohort, therefore it was important to describe the cohort sociodemographic profile. Although socio-demographic characteristics compared well with national data, there was an over-representation of educated mothers which may limit the generalizability of the results. From August 2008 through November 2011, comprehensive postnatal assessments were completed at day 2 and at 2, 6, 12 and 24 months. Breastfeeding rates were low, while complementary feeding practices were broadly compliant with national guidelines. The implementation of a national infant vitamin D supplementation policy had a major impact on supplementation practice. Low levels of serum 25(OH)D were universal among Irish neonates. Eczema is a complex and multifaceted disease, which is increasing globally. This was the first report of eczema prevalence data among Irish infants which compared with international reports. Given the high prevalence and considerable burden eczema has on the lives of sufferers, intensive research efforts to identify a cause and therapeutic strategies to prevent/reduce eczema was re-emphasized in this thesis.

Nutrition, growth and body composition in preterm infants

The goal of neonatal nutrition in the preterm infant is to achieve postnatal growth and body composition approximating that of a normal fetus of the same postmenstrual age and to obtain a functional outcome comparable to infants born at term. However, in clinical practice such a pattern is seldom achieved, with growth failure and altered body composition being extensively reported. The BabyGrow preterm nutrition study was a longitudinal, prospective, observational study designed to investigate nutrition and growth in 59 preterm infants following the implementation of evidence-based nutrition guidelines in the neonatal unit at Cork University Maternity Hospital. Nutrient delivery was precisely measured during the entire hospital stay and intakes were compared with current international recommendations. Barriers to nutrient delivery were identified across the phases of nutritional support i.e. exclusive parenteral nutrition and transition (establishment of enteral feeds) phases of nutrition and nutritional strategies to optimise nutrient delivery were proposed according to these phases. Growth was measured from birth up to 2 months corrected age and body composition was assessed in terms of fat mass and lean body mass by air displacement plethysmography (PEA POD) at 34 weeks gestation, term corrected age and 2 months corrected age. Anthropometric and body composition data in the preterm cohort were compared with a term reference group from the Cork BASELINE Birth Cohort Study (n=1070) at similar time intervals. The clinical and nutritional determinants of growth and body composition during the neonatal period were reported for the first time. These data have international relevance, informing authoritative agencies developing evidence-based practice guidelines for neonatal nutritional support. In the future, the nutritional management of preterm infants may need to be individualised to consider gestational age, birth weight as well as preterm morbidity.

Nutrition, growth and body composition in infancy

This thesis is presented in two parts. Data for this research is from the Cork BASELINE (Babies after SCOPE, Evaluating Longitudinal Impact using Neurological and Nutritional Endpoints) Birth Cohort Study (n = 2137). In this prospective birth cohort study, pediatric follow-up with in-person appointments were repeated from the time of birth through to 2, 6 and 12 months, and at 2 years. Body composition was measured by air displacement plethysmography at birth and at 2 months using the PEA POD Infant Body Composition Tracking System. This thesis provides the first extensive report on the study’s 2 year assessment. In part one, the aims were to investigate potential early-life risk factors for childhood overweight and obesity, including rapid growth and body composition in infancy and umbilical cord concentrations of leptin and high molecular weight (HMW) adiponectin. This research is the first to describe rapid growth in early infancy in terms of changes in direct measures of body composition. These are also the first data to examine associations between umbilical cord leptin and HMW adiponectin concentrations and changes in fat and lean mass in early infancy. These data provide additional insight into characterising the growth trajectory in infancy and into the role of perinatal factors in determining infant growth and subsequent overweight/obesity risk. In part two of this thesis, the aims were to quantify vitamin D intake and status at 2 years and to investigate whether 25-hydroxyvitamin D [25(OH)D] concentrations in early pregnancy and in umbilical cord blood are associated with infant growth and body composition. There was a low prevalence of vitamin D deficiency among Irish 2 year olds (n = 742) despite a high prevalence of inadequate intakes and high latitude (51°N). Maternal 25(OH)D concentrations at 15 weeks gestation and cord 25(OH)D concentrations at delivery were not associated with infant growth or adiposity.

The effect of complex workplace dietary interventions on employees dietary behaviours, nutrition knowledge and health status

Background The growing prevalence and associated burden of diet-related non-communicable diseases is a global public health concern. The environments in which people live and work influences their dietary behaviours. Aim The focus of this thesis was on the effectiveness of complex workplace dietary interventions. The comparative effectiveness of a complex workplace environmental dietary modification intervention and an educational intervention were assessed both alone and in combination relative to a control workplace setting. Methods The systematic review was guided by the PRISMA statement. In a cluster controlled trial, four workplaces were purposively allocated to control, nutrition education alone (Education), environmental dietary modification alone (Environment) and nutrition education and environmental dietary modification (Combined intervention). The interventions were guided by the MRC framework. In the control workplace, data were collected at baseline and follow-up. In the intervention related sub-study, the relationships between nutrition knowledge, diet quality and hypertension were examined. Results The systematic review provided limited evidence. In the FCW study, 850 employees aged 18-64 years were recruited at baseline with N(response rate %) in each workplace as follows: Control: 111(72%), Education: 226(71%), Environment: 113(91%), Combined intervention: 400(61%). Complete follow-up data was obtained for 517 employees (61%). There were significant positive changes in dietary intakes of saturated fat(p=0.013), salt(p=0.010) and nutrition knowledge(p=0.034) between baseline and follow-up at 7-9 months in the combined intervention versus the control workplace in the fully adjusted multivariate analysis. Small but significant changes in BMI(-1.2kg/m2 (p=0.047) were also observed in the combined intervention. In the sub-study, nutrition knowledge was positively significantly associated with diet quality and blood pressure but no evidence of a mediation effect of the DASH score was detected between nutrition knowledge and blood pressure. Conclusion This thesis provides critical evidence on the effectiveness of complex workplace dietary interventions in a manufacturing working population.

Infant nutrition and the gut microbiota

Establishment of the intestinal microbiota commences at birth and this colonisation is influenced by a number of factors including mode of delivery, gestational age, mode of feeding, environmental factors and host genetics. As this initial establishment may well influence the health of an individual later in life, it is imperative to understand this process. Therefore, this thesis set out to investigate how early infant nutrition influences the development of a healthy gut microbiota. As part of the INFANTMET project, the intestinal microbiota of 199 breastfed infants was investigated using both culture-dependent and culture-independent approaches. This study revealed that delivery mode and gestational age had a significant impact on early microbial communities. In order to understand host genotype-microbiota interactions, the gut microbiota composition of dichorionic triplets was also investigated. The results suggested that initially host genetics play a significant role in the composition of an individual’s gut microbiota, but by month 12 environmental factors are the major determinant. To investigate the origin of hydrogen sulphide in a case of nondrug- induced sulfhemoglobinemia in a preterm infant, the gut microbiota composition was determined. This analysis revealed the presence of Morganella morganii, a producer of hydrogen sulphide and hemolysins, at a relative abundance 38%, which was not detected in control infants. Following on from this, the negative and short term consequences of intrapartum antibiotic prophylaxis exposure on the early infant intestinal microbiota composition were demonstrated, particularly in breast-fed infants, which are recovered by day 30. Finally, the composition of the breast milk microbiota over the first three months of life was characterised. A core of 12 genera were identified amongst women and the remainder comprised some 195 genera which were individual specific and subject to variations over time. The results presented in this thesis have demonstrated that the development of the infant gut microbiota is complex and highly individual. Clear alterations in the intestinal microbiota establishment process in C-section delivered, preterm and antibiotic exposed infants were shown. Taken together, long-term health benefits for infants, particularly those vulnerable groups, may be conferred through the design of probiotic and prebiotic food ingredients and supplements.