title: Gender differences in cerebral glucose metabolism: a PET study.
abstract: OBJECTIVE
  Some studies have examined gender differences in brain function based on cerebral blood flow and cerebral metabolism by using positron emission tomography (PET). However, the findings of these studies are controversial and most of them were analyzed by the regions of interest (ROIs) method. Here, we evaluated gender differences of cerebral glucose metabolism under the resting state in a voxel-based analysis.
  
  
  METHODS
  We studied 44 healthy volunteers (22 females, 63.0+/-6.3 years, and 22 males, 63.1+/-8.4 years). Cerebral glucose metabolic images were obtained with (18)F-fluorodeoxyglucose (FDG) and PET. All individual data were transformed to standard brain space and the male and female groups were compared using statistical parametric mapping (SPM).
  
  
  RESULTS
  The males had significantly higher glucose metabolism in the right insula, middle temporal gyrus, and medial frontal lobe than the females. Glucose metabolism in the hypothalamus was significantly higher in females than in males. There was a significant correlation between aging and glucose metabolism in the left thalamus in males and in the left caudate nucleus and hypothalamus in females. In males, but not females, there was a significant asymmetry between the bilateral hemispheres.
  
  
  CONCLUSIONS
  We found that there were obvious gender differences in regional cerebral glucose metabolism and this is the first report of higher glucose metabolism in the hypothalamus in females than in males.
authors.affiliation: Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, 520 Saisho-Ko, Himeji, Hyogo 670-0981, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawachi
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishii
authors.forename: Setsu
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Mieko
authors.initials: M
authors.lastname: Matsui
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mori
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007031:Hypothalamus / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism; D014055:Tomography, Emission-Computed
chemical_list: D005947:Glucose