title: Human brain chemical shift imaging at age 60 to 90: analysis of the causes of the observed sex differences in brain metabolites.
abstract: OBJECTIVE
  To assess whether differences in cerebral atrophy and white matter lesions or in the presence of lactate and lipid signals can explain the observed differences in brain choline, creatine, and N-acetylaspartate levels between healthy elderly women and men.
  
  
  METHODS
  In addition to standard magnetic resonance imaging of the brain, an 8 x 8 x 2-cm3 supraventricular transverse brain volume parallel to the canthomeatal line was examined by magnetic resonance spectroscopy (automated 1H chemical shift imaging) in 540 healthy elderly persons.
  
  
  RESULTS
  At P = 0.01, 0.001, and 0.0001, choline differed between women and men in 14, 9, and 5 of 36 voxels, respectively. On correction for cerebral atrophy (more frequent in men than in women), white matter lesions (more frequent in women), and lactate and lipid (more frequent in women), the differences in choline were reduced to 13, 6, and 3. Sex differences for creatine and N-acetylaspartate were similar but less numerous after correction.
  
  
  CONCLUSIONS
  Elderly women and men in the general population show differences in the levels of creatine, N-acetylaspartate, and especially choline in portions of the brain. The sex-related differences in brain metabolite levels cannot be explained by differences in cerebral atrophy or other aging-related phenomena (white matter lesions, lactate, lipid).
authors.affiliation: Department of Radiology, State University and Academic Hospital Groningen, The Netherlands. p.e.sijens@rad.azg.nl
authors.forename: P E
authors.initials: PE
authors.lastname: Sijens
authors.forename: T
authors.initials: T
authors.lastname: Den Heijer
authors.forename: F E
authors.initials: FE
authors.lastname: De Leeuw
authors.forename: J C
authors.initials: JC
authors.lastname: De Groot
authors.forename: E
authors.initials: E
authors.lastname: Achten
authors.forename: R J
authors.initials: RJ
authors.lastname: Heijboer
authors.forename: A
authors.initials: A
authors.lastname: Hofman
authors.forename: M M
authors.initials: MM
authors.lastname: Breteler
authors.forename: M
authors.initials: M
authors.lastname: Oudkerk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001284:Atrophy / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001923:Brain Chemistry; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D012737:Sex Factors
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline