NEONATAL SOCIETY ABSTRACTS
Differential regulation of subcutaneous and visceral adipose tissue mass in early infancy
Presented at the Neonatal Society 2002 Summer Meeting (programme).
Harrington TAM1, Thomas EL2, Modi N1, Frost G3, Bell JD2
1 Section of Paediatrics & Neonatal Medicine, Imperial College
Faculty of Medicine, London, UK
2 Robert Steiner MR Unit, MRC Clinical Sciences Centre, London, UK
3 Department of Dietetics, Hammersmith Hospital, London, UK
Background: In adults the regulation of adiposity is of interest as the quantity and distribution of adipose tissue (AT) are related to later morbidity. An increasing body of largely epidemiological data show that infants who were small and thin at birth have an increased prevalence in adult life of biological risk factors strongly associated with visceral adiposity. Little is known about the regulation of AT mass deposition in early life.
Aim: The aim of this study was to compare total and differential AT distribution at birth and at 6 weeks of age in full term appropriately grown (AG) and growth restricted (GR) infants.
Methods: Infants were classified as GR if they had evidence of deceleration in growth in utero, clinical signs at birth suggestive of fetal malnutrition and a birth weight below the 10th centile. Total AT mass and regional (subcutaneous, visceral, other internal) AT distribution were assessed by magnetic resonance imaging using a technique we have developed for application to infants (Harrington et al 2002). The study was approved by the institutional Research Ethics Committee. Written informed parental consent was obtained. Total and regional AT were compared birth and at 6 weeks of age in AG and GR infants using multiple regression analysis allowing for postmenstrual age at imaging. Data are presented as mean (SD).
Results: GR infant had a significantly reduced AT content at birth compared to AG infants. This difference arose from a reduction in subcutaneous AT, but not visceral or other internal AT (table 1). There was a rapid increase in subcutaneous AT mass so that by 6 weeks of age there was no longer a difference between AG and GR infants (table 2). In contrast, the content of visceral and other internal AT mass remained essentially unchanged.
Conclusions: MRI adipose tissue imaging confirms that subcutaneous AT is reduced in the GR neonate at birth but also demonstrates that visceral AT mass is preserved. By 6 weeks GR infants have preferentially accumulated subcutaneous, but not visceral AT. We conclude that subcutaneous AT and visceral AT are under different regulatory control in early infancy.
Harrington TA, Thomas EL, Modi N et al. Lipids 2002; 37:95-100