title: Sex-dependent influences of obesity on cerebral white matter investigated by diffusion-tensor imaging.
abstract: Several studies have shown that obesity is associated with changes in human brain function and structure. Since women are more susceptible to obesity than men, it seems plausible that neural correlates may also be different. However, this has not been demonstrated so far. To address this issue, we systematically investigated the brain's white matter (WM) structure in 23 lean to obese women (mean age 25.5 y, std 5.1 y; mean body mass index (BMI) 29.5 kg/m(2), std 7.3 kg/m(2)) and 26 lean to obese men (mean age 27.1 y, std 5.0 y; mean BMI 28.8 kg/m(2), std 6.8 kg/m(2)) with diffusion-weighted magnetic resonance imaging (MRI). There was no significant age (p>0.2) or BMI (p>0.7) difference between female and male participants. Using tract-based spatial statistics, we correlated several diffusion parameters including the apparent diffusion coefficient, fractional anisotropy (FA), as well as axial (λ(∥)) and radial diffusivity (λ(⊥)) with BMI and serum leptin levels. In female and male subjects, the putative axon marker λ(∥) was consistently reduced throughout the corpus callosum, particularly in the splenium (r = -0.62, p<0.005). This suggests that obesity may be associated with axonal degeneration. Only in women, the putative myelin marker λ(⊥) significantly increased with increasing BMI (r = 0.57, p<0.005) and serum leptin levels (r = 0.62, p<0.005) predominantly in the genu of the corpus callosum, suggesting additional myelin degeneration. Comparable structural changes were reported for the aging brain, which may point to accelerated aging of WM structure in obese subjects. In conclusion, we demonstrate structural WM changes related to an elevated body weight, but with differences between men and women. Future studies on obesity-related functional and structural brain changes should therefore account for sex-related differences.
authors.affiliation: Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. karstenm@cbs.mpg.de
authors.forename: Karsten
authors.initials: K
authors.lastname: Mueller
authors.forename: Alfred
authors.initials: A
authors.lastname: Anwander
authors.forename: Harald E
authors.initials: HE
authors.lastname: Möller
authors.forename: Annette
authors.initials: A
authors.lastname: Horstmann
authors.forename: Jöran
authors.initials: J
authors.lastname: Lepsien
authors.forename: Franziska
authors.initials: F
authors.lastname: Busse
authors.forename: Siawoosh
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Matthias L
authors.initials: ML
authors.lastname: Schroeter
authors.forename: Michael
authors.initials: M
authors.lastname: Stumvoll
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.forename: Burkhard
authors.initials: B
authors.lastname: Pleger
mesh_terms: D000328:Adult; D016880:Anisotropy; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D054022:Cerebrum / Q000473:pathology*; D003337:Corpus Callosum / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood; D008297:Male; D015233:Models, Statistical; D009765:Obesity / Q000097:blood / Q000473:pathology* / Q000503:physiopathology; D012727:Sex Characteristics
chemical_list: D020738:Leptin