Objective To determine associations between body composition and concurrent measures of brain development including (1) Tissue-specific brain volumes and (2) White matter microstructure, among very preterm infants at term equivalent age.
Design Prospective observational study.
Setting Single-centre academic level III neonatal intensive care unit.
Patients We studied 85 infants born <33 weeks’ gestation.
Methods At term equivalent age, infants underwent air displacement plethysmography to determine body composition, and brain MRI from which we quantified tissue-specific brain volumes and fractional anisotropy (FA) of white matter tracts. We estimated associations of fat and lean mass Z-scores with each brain outcome, using linear mixed models adjusted for intrafamilial correlation among twins and potential confounding variables.
Results Median gestational age was 29 weeks (range 23.4–32.9). One unit greater lean mass Z-score was associated with larger total brain volume (10.5 cc, 95% CI 3.8 to 17.2); larger volumes of the cerebellum (1.2 cc, 95% CI 0.5 to 1.9) and white matter (4.5 cc, 95% CI 0.7 to 8.3); and greater FA in the left cingulum (0.3%, 95% CI 0.1% to 0.6%), right uncinate fasciculus (0.2%, 95% CI 0.0% to 0.5%), and right posterior limb of the internal capsule (0.3%, 95% CI 0.03% to 0.6%). Fat Z-scores were not associated with any outcome.
Conclusions Lean mass—but not fat—at term was associated with larger brain volume and white matter microstructure differences that suggest improved maturation. Lean mass accrual may index brain growth and development.
Data availability statement
Data are available upon reasonable request. The data that support the findings of this study are available from the corresponding author, KAB, upon reasonable request.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
Contributors KAB designed the study and analysis, assisted with data collection, analysed the data, wrote the first draft of the manuscript, and is the guarantor for this work. LGM, SKW, AKP and SO performed image processing and analysis.LGM, SC, TEI and MBB assisted with study methodology and interpretation of results. KAB and SC analysed the data and all authors contributed to interpretation of findings. All authors contributed to editing the manuscript and have approved the submission of this version of the manuscript and take full responsibility for its content.
Funding Portions of this study were supported by a Marshall Klaus Perinatal Research Award from the American Academy of Pediatrics (KAB); Early Career Award from The Gerber Foundation (KAB); the Brigham Research Institute and Brigham and Women’s Hospital Stork Fund (MBB); Program for Interdisciplinary Neuroscience Traveling Fellowship from the Brigham and Women’s Hospital (LGM); R01 EB019483 from the National Institute of Biomedical Imaging and Bioengineering (SKW, AKP); and by Clinical Translational Science Award UL1RR025758 to Harvard University and Brigham and Women’s Hospital from the National Center for Research Resources. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center for Research Resources or the National Institutes of Health.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.