title: Vitamin D-related changes in intracranial volume in older adults: a quantitative neuroimaging study.
abstract: OBJECTIVE
  Vitamin D is involved in skeletal and brain health. Recently, serum 25-hydroxyvitamin D (25OHD) concentration was found to be inversely correlated with intracranial volume in younger adults. Since hypovitaminosis D is most common in older adults, our objective was to determine whether this inverse correlation between 25OHD concentration and intracranial volume also occurred in older adults.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  One hundred and ten Caucasian older community-dwellers (mean, 71.7±5.7 years; 45.5% female) received a blood test and an MRI of the brain at the same period. The intracranial volume and the subvolumes of cerebrospinal fluid, total brain, infratentorial brain, supratentorial brain, total white matter, total gray matter, cortical gray matter and subcortical gray matter were measured using FreeSurfer volumetry on T1-weighted images. Vitamin D insufficiency was defined as serum 25OHD<50nmol/L. Age, gender, body mass index, education level, use of vitamin D supplements, season of evaluation, serum concentrations of calcium and thyroid stimulating hormone were used as covariables in the analysis.
  
  
  RESULTS
  We found that participants with vitamin D insufficiency (n=41) had greater intracranial volume than those without (1555.0±1379.2cm(3) versus 1488.0±167.4cm(3), P=0.033). Serum 25OHD concentration was cross-sectionally associated with decreased intracranial volume in mm(3) (unadjusted β=-1194.4, P=0.028), even after adjustment for covariables (adjusted β=-994.3, P=0.048). We found an inverse correlation of serum 25OHD with intracranial volume (r=-0.21, P=0.028) and the volume of white matter (r=-0.20, P=0.033). The other subvolumes did not correlate with serum 25OHD concentration.
  
  
  CONCLUSIONS
  Serum 25OHD concentration was independently and inversely associated with intracranial volume in older adults.
authors.affiliation: Department of Geriatric Medicine, Angers University Hospital; UPRES EA4638, University of Angers, UNAM, France; Research Center on Autonomy and Longevity (CeRAL), Angers, France; Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, ON, Canada. Electronic address: CeAnnweiler@chu-angers.fr.
authors.forename: Cedric
authors.initials: C
authors.lastname: Annweiler
authors.affiliation: Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, ON, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Bartha
authors.affiliation: Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, ON, Canada.
authors.forename: Sandy
authors.initials: S
authors.lastname: Goncalves
authors.affiliation: Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Greece.
authors.forename: Spyridon N
authors.initials: SN
authors.lastname: Karras
authors.affiliation: Aix Marseille University, NICN, CNRS UMR 7259, Center for Clinical Investigations in Biotherapy, Marseille, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Millet
authors.affiliation: Aix Marseille University, NICN, CNRS UMR 7259, Center for Clinical Investigations in Biotherapy, Marseille, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Féron
authors.affiliation: Department of Geriatric Medicine, Angers University Hospital; UPRES EA4638, University of Angers, UNAM, France; Research Center on Autonomy and Longevity (CeRAL), Angers, France; Biomathics, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Beauchet
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005602:France; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D059906:Neuroimaging; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000473:pathology*; D066127:White Matter / Q000473:pathology*; D044465:White People
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Brain; Intracranial volume; Magnetic resonance imaging; Older adults; Vitamin D