Poster Topical Area: Neurobiology
Location: Hall D
Poster Board Number: 700
Objectives: Iron deficiency is a leading micronutrient deficiency that especially affects infants and young children in developing nations. If not addressed, it can lead to anemia and reduced brain iron content, which may cause permanent neurological deficits. Thus, there is a need to understand how early-life iron status affects longitudinal neurodevelopment. This study compared hematocrit (Hct) and hemoglobin (Hb) levels in the pig at postnatal day (PND) 32 to magnetic resonance imaging (MRI) measures of neurodevelopment at PND 61 in a longitudinal manner.
Methods:Sixteen intact male pigs were provided ad libitum access to control (21.3 mg Fe/L) or iron-deficient (2.72 mg Fe/L) milk replacers from PND 2 to 32, after which all pigs were switched to a common set of iron-adequate diets and subjected to MRI procedures at PND 60. Brain microstructure was quantified using diffusion tensor imaging to assess fractional anisotropy (FA), and mean (MD), radial (RD), and axial (AD) diffusivity. Quantitative susceptibility imaging (QSM) was also used to detect altered brain iron status throughout the brain. A correlation matrix was computed to identify significant associations between hematological markers and neuroimaging outcomes, and linear regressions were used to assess the strength of those relationships<./p>
Results: Both Hct (%) and Hb (g/dl) were correlated with 103 out of 127 possible MRI measures. Most relationships between blood measures and brain FA showed a positive association (9 of 11 correlations; P < 0.05). Negative correlations were observed between blood measures and MD (9 of 11 correlations; P < 0.05), RD (9 of 11 correlations; P < 0.05), and AD (8 of 11 correlations; P < 0.05). Both Hct and Hb negatively predicted QSM in the olfactory bulbs (Hct: β = -0.000134, r2 = 0.517, P = 0.019; Hb: β = -0.000393, r2 = 0.515, P = 0.019) and positively predicted QSM in the pons (Hct: β = 0.000960, r2 = 0.536, P = 0.01; Hb: β = 0.002824, r2 = 0.538, P = 0.01).
Conclusion: Hematological measures at PND 32 (end of iron deficiency period) were shown to be highly predictive of MRI measures at PND 61 (after dietary iron repletion period), including iron content in brain tissue. These data suggest blood markers early in life may be predictive of future brain microstructure and iron concentrations in discrete brain regions.
Graduate Research Assistant
University of Illinois at Urbana-Champaign