title: Specific white matter tissue microstructure changes associated with obesity.
abstract: Obesity-related structural brain alterations point to a consistent reduction in gray matter with increasing body mass index (BMI) but changes in white matter have proven to be more complex and less conclusive. Hence, more recently diffusion tensor imaging (DTI) has been employed to investigate microstructural changes in white matter structure. Altogether, these studies have mostly shown a loss of white matter integrity with obesity-related factors in several brain regions. However, the variety of these obesity-related factors, including inflammation and dyslipidemia, resulted in competing influences on the DTI indices. To increase the specificity of DTI results, we explored specific brain tissue properties by combining DTI with quantitative multi-parameter mapping in lean, overweight and obese young adults. By means of multi-parameter mapping, white matter structures showed differences in MRI parameters consistent with reduced myelin, increased water and altered iron content with increasing BMI in the superior longitudinal fasciculus, anterior thalamic radiation, internal capsule and corpus callosum. BMI-related changes in DTI parameters revealed mainly alterations in mean and axial diffusivity with increasing BMI in the corticospinal tract, anterior thalamic radiation and superior longitudinal fasciculus. These alterations, including mainly fiber tracts linking limbic structures with prefrontal regions, could potentially promote accelerated aging in obese individuals leading to an increased risk for cognitive decline.
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Germany. Electronic address: stephanie.kullmann@med.uni-tuebingen.de.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kullmann
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK.
authors.forename: Martina F
authors.initials: MF
authors.lastname: Callaghan
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Department of Internal Medicine IV, University of Tübingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Heni
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK; Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Weiskopf
authors.affiliation: Department of Biomedical Magnetic Resonance, University of Tübingen, Germany; Department of High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Scheffler
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Department of Internal Medicine IV, University of Tübingen, Germany.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Häring
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Department of Internal Medicine IV, University of Tübingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fritsche
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Veit
authors.affiliation: Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Tübingen, Germany; Department of Internal Medicine IV, University of Tübingen, Germany; Department Pharmacy and Biochemistry, Faculty of Science, Eberhard Karls Universität Tübingen, Tübingen, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Preissl
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D009765:Obesity / Q000150:complications*; D066127:White Matter / Q000473:pathology*; D055815:Young Adult
keywords: DTI; Multi-parametric mapping; Obesity; Quantitative MRI