Memory Performance and Hippocampal Volumes in Healthy Weight Children at High- and Low-Familial Risk for Obesity

Children with overweight or obesity (OW/OB), relative to healthy weight (HW), have lower cognitive performance and hippocampal volumes. Whether this extends to children with HW at familial risk for future OW/OB is unknown.

To compare memory performance and hippocampal subfield volumes between HW children at high risk (HR) and low risk (LR) for OW/OB.

HW children (n = 95, aged 8-11), classified as HR (n = 43, both parents with OW/OB) or LR (n = 52, both parents with HW), underwent structural magnetic resonance imaging and memory testing (Verbal List Learning Test-Food-Child Version (VLLT-Food-C) and Child Memory Scale subtests: word pairs, dot locations). Linear models tested group differences in memory scores, hippocampal and subfield (CA1, CA3, dentate gyrus (DG), subiculum) volumes.

Groups did not differ on demographics except body mass index (HR > LR, p = 0.003), despite all children being HW. LR children performed better on VLLT-Food-C short- ( $\beta$  = 0.34, p < 0.01) and long-delay cued recall ( $\beta$  = 0.21, p = 0.04) and word pairs delayed recall ( $\beta$  = 0.21, p = 0.04). Children with HR had smaller bilateral whole hippocampus, CA1, DG and right CA3 volumes (ps < 0.05); only the right DG remained significant ( $\beta$  = 0.15, p = 0.04) after intracranial volume adjustment.

Memory and hippocampal volume differences may reflect underlying familial risk of OW/OB in HW children.