Prior EL, Longford N, Emsley R, Gale C, Uthaya S, Modi N

Institution(s)

Section of Neonatal Medicine, Imperial College London, Chelsea and Westminster Hospital campus, 369 Fulham Road, London, SW10 9NH, UK

Introduction (include hypothesis)

Preterm birth is associated with adverse cardiometabolic health in later life1,2 but mechanisms are unknown. We have previously identified a difference in adiposity between preterm infants at term age and full term babies, and between young adults born preterm and at term. However, there are no longitudinal studies exploring the changes in adiposity in preterm or term infants into childhood or adulthood. We aim to address the hypotheses that adiposity in preterm and term infants tracks into childhood and that the difference in adiposity persists into childhood. We therefore performed a pilot study to assess the feasibility of performing whole body magnetic resonance imaging (MRI) to assess body composition in children aged 6-9 years.

Methods (include source of funding and ethical approval if required)

We invited participation from a cohort of very preterm (n=154) and full-term (n=127) children who took part in three studies we conducted during the neonatal period; all underwent whole body MRI at term corrected age or shortly after birth. We obtained research ethics approval (16/LO/1459) and grant funding from Westminster Medical School Trust. We conducted whole body MRI and compared total Adipose Tissue (AT) and each of six predefined AT compartments (fig) between children born preterm and full-term. A commercial provider (www.vardisgroup.com) performed image analysis blind to patient group, using standard protocols and software (SliceOMatic). We adjusted adipose tissue volumes for body size as previously described 3, to allow meaningful comparison between individuals.  We present results as adjusted mean difference (95% confidence interval).

Results

We approached all families of children who had participated in the three neonatal studies (n= 281). Over 75% indicated they were interested in having their children take part in this study. At time of initial contact, the children in the cohort ranged from 3-9 years of age, hence we recruited the oldest children first. We successfully imaged all of the first 30 children (16 preterm) recruited (age range 6 to 9 years).  Adjusted mean differences between preterm and full-term children were: total AT (9.5%, 95% CI -8.5, 31.1), SSCA (16.8%, 95% CI -10.7, 52.9), SSCNA (11.8%, 95% CI -7.4, 35.0) and DSCA (97.6%, 95% CI 2.1, 282.5). 

Conclusions

Assessment of adiposity using whole body MRI is feasible in childhood. We now plan to proceed to a larger study with power to detect clinically relevant differences between preterm and term born children. If differences in AT identified in the neonatal period persist into childhood, this would strengthen the possibility that later risks to cardiometabolic health in adults born preterm are mediated by altered adiposity.