Open AccessVitamin D deficiency is associated with reduced hippocampal volume and disrupted structural connectivity in patients with mild cognitive impairment
Author(s) -
AlAmin Mamun,
Bradford DanaKai,
Sullivan Robert K. P.,
Kurniawan Nyoman D.,
Moon Yeonsil,
Han SeolHeui,
Zalesky Andrew,
Burne Thomas H. J.
Publication year - 2019
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.24380
Subject(s) - neurocognitive , hippocampal formation , dentate gyrus , hippocampus , fractional anisotropy , dementia , neuroscience , atrophy , biomarker , temporal lobe , vitamin d and neurology , vitamin d deficiency , psychology , white matter , medicine , cognitive decline , cognition , disease , magnetic resonance imaging , chemistry , epilepsy , radiology , biochemistry
Vitamin D deficiency may exacerbate adverse neurocognitive outcomes in the progression of diseases such as Parkinson's, Alzheimer's, and other dementias. Mild cognitive impairment (MCI) is prodromal for these neurocognitive disorders and neuroimaging studies suggest that, in the elderly, this cognitive impairment is associated with a reduction in hippocampal volume and white matter structural integrity. To test whether vitamin D is associated with neuroanatomical correlates of MCI, we analyzed an existing structural and diffusion MRI dataset of elderly patients with MCI. Based on serum 25‐OHD levels, patients were categorized into serum 25‐OHD deficient (<12 ng/mL, n = 27) or not‐deficient (>12 ng/mL, n = 29). Freesurfer 6.0 was used to parcellate the whole brain into 164 structures and segment the hippocampal subfields. Whole‐brain structural connectomes were generated using probabilistic tractography with MRtrix. The network‐based statistic (NBS) was used to identify subnetworks of connections that significantly differed between the groups. We found a significant reduction in total hippocampal volume in the serum 25‐OHD deficient group especially in the CA1, molecular layer, dentate gyrus, and fimbria. We observed a connection deficit in 13 regions with the right hippocampus at the center of the disrupted network. Our results demonstrate that low vitamin D is associated with reduced volumes of hippocampal subfields and connection deficits in elderly people with MCI, which may exacerbate neurocognitive outcomes. Longitudinal studies are now required to determine if vitamin D can serve as a biomarker for Alzheimer's disease and if intervention can prevent the progression from MCI to major cognitive disorders.