Presented at the Neonatal Society 2008 Autumn Meeting.
Vasu V1, Durighel G2, Uthaya S1, Bell JD2, Rutherford MA2, Modi N1
1 1Section of Neonatal Medicine, Division of Medicine, Imperial College London, Chelsea & Westminster Campus, 369 Fulham Road, London, SW10 9NH, UK
2 2Division of Clinical Sciences, Imperial College London and MRC Clinical Sciences Centre Hammersmith Hospital, DuCane Road, London, W12 0HS, UK
Background: Using magnetic resonance angiography (MRA), we have previously shown that proximal segment cerebral arterial vessel tortuosity differs between preterm infants at term and healthy term born controls, with a reduction in tortuosity seen in the former group1. As vascular development is closely linked to brain development, this finding may be a correlate of later neurodevelopmental dysfunction in preterm infants. Little is known about what factors mediate changes in vessel tortuosity.
Aim: We are conducting a large prospective observational cohort study investigating the influence of preterm nutrition upon magnetic resonance indices of somatic and brain development. Here we describe relationships between preterm nutrition and proximal cerebral vessel tortuosity in a contemporaneous cohort of preterm infants.
Methodology: Research ethics permission for this study was granted by St Mary’s Hospital NHS Trust and written parental consent was obtained. We studied 20 preterm infants (GA <33 weeks) and 13 term infants using a 3 Tesla Phillips Achieva magnetic resonance scanner. Time of flight MRA images were obtained using previously optimized parameters and proximal segment cerebral vessel tortuosity measured for the anterior (ACA), middle (MCA) and posterior cerebral (PCA) arteries using ImageJ software1. Distance factor (DF) was used as a measure of proximal cerebral arterial vessel tortuosity as previously described2 and a single mean DF value calculated for each group. Neonatal nutritional information was collected from birth to 34+6 weeks postmenstrual age using an in house designed neonatal nutritional data capture system (NutcrackerTM). Macronutrient data are presented as the cumulative difference between mean of actual daily intake and the recommended daily intake in g/kg.day. Human milk intake is expressed as mls/kg.day and as percentage of enteral feeds given as human milk. Univariate methods were used for analysis (SPSS version 16).
Results: DF score was significantly reduced in preterm at term infants in comparison to term infants (p<0.001). Distance factor score in the preterm group demonstrated a significant positive correlation with human milk intake (r=0.44, p=0.05) and percentage of enteral feeds given as human milk (r=0.45, p=0.04). There was no significant relationship between DF score and fat, protein, carbohydrate or energy intake.
Conclusion: We have replicated our previous observation demonstrating that by term age preterm infants have reduced proximal cerebral vessel tortuosity when compared to term born healthy controls. Furthermore, our data indicate that human milk intake may be a determinant of cerebral vessel tortuosity. Given the dissociation observed between macronutrient intake and cerebral vessel tortuosity it also opens up the possibility that non-nutritive factors in human milk are responsible for these observations.
References
1. Malamateniou C, Counsell SJ, Allsop JM, et al. Neuroimage.2006; 32(3);1050-1059.
2. Bullitt E, Gerig G, Pizer SM, Lin W, Aylward SR. IEEE Trans. Med. Imaging. 2003; 22(9):1163–1171.