title: Feasibility study: Assessing the influence of macronutrient intakes on preterm body composition, using air displacement plethysmography.
abstract: OBJECTIVE
  Preterm nutrition guidelines target nutrient accretion and growth at intrauterine rates, yet at term equivalent age, the phenotype of the preterm infant differs from that of term infants. Monitoring early changes in preterm body composition (BC) in response to macronutrient intakes may facilitate our understanding of how best to meet preterm nutrition and growth targets.
  
  
  METHODS
  Macronutrient intakes based on milk analysis were calculated from birth for infants born <33 weeks gestation. BC was measured in the PEA POD when infants were thermodynamically stable, free of intravenous lines and independent of respiratory support. Subsequent BC measurements were taken at least fortnightly until term age. Regression analysis was used to assess macronutrient influences on changes in BC.
  
  
  RESULTS
  Median (range) gestation and birthweight of preterm infants (n = 27) were 29 (25-32) weeks and 1395 (560-2148) g, respectively. The youngest corrected gestational and postnatal ages that infants qualified for a PEA POD measurement were 31.86 and 1.43 weeks, respectively. Fat and total energy intakes were positively associated with increasing fat mass. Protein (with carbohydrate) intake was positively associated with increasing fat-free mass.
  
  
  CONCLUSIONS
  Preterm infants can be measured in the PEA POD as early as 31 weeks corrected gestational age and the method appears sufficiently sensitive to detect influences of macronutrient intake on changes in BC.
authors: Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia.
authors: Gemma
authors: G
authors: McLeod
authors: Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Western Australia, Australia.
authors: Karen
authors: K
authors: Simmer
authors: School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.
authors: Jill
authors: J
authors: Sherriff
authors: Women and Infants' Research Foundation, The University of Western Australia, Perth, Western Australia, Australia.
authors: Elizabeth
authors: E
authors: Nathan
authors: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Western Australia, Australia.
authors: Donna
authors: D
authors: Geddes
authors: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, Western Australia, Australia.
authors: Peter
authors: P
authors: Hartmann
mesh_terms: D000818:Animals; D000886:Anthropometry; D001823:Body Composition / Q000502:physiology*; D002149:Energy Intake; D005240:Feasibility Studies; D005247:Feeding Behavior; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007234:Infant, Premature / Q000254:growth & development*; D008895:Milk, Human / Q000737:chemistry*; D010991:Plethysmography / Q000379:methods
keywords: air displacement plethysmography; body composition; preterm infant; preterm nutrition