title: Age-related differences in metabolites in the posterior cingulate cortex and hippocampus of normal ageing brain: a 1H-MRS study.
abstract: OBJECTIVE
  To study age-related metabolic changes in N-acetylaspartate (NAA), total creatine (tCr), choline (Cho) and myo-inositol (Ins).
  
  
  METHODS
  Proton magnetic resonance spectroscopy (1H-MRS) was performed in the posterior cingulate cortex (PCC) and the left hippocampus (HC) of 90 healthy subjects (42 women and 48 men aged 18-76 years, mean±SD, 48.4±16.8 years). Both metabolite ratios and absolute metabolite concentrations were evaluated. Analysis of covariance (ANCOVA) and linear regression were used for statistical analysis.
  
  
  RESULTS
  Metabolite ratios Ins/tCr and Ins/H2O were found significantly increased with age in the PCC (P<0.05 and P≤0.001, respectively), and in the HC (P<0.01 for both). An increased tCr/H2O was only observed in the PCC (P<0.01). Following absolute quantification based on the internal water signal, significantly increased concentrations of Ins and tCr in the PCC confirmed the relative findings (P<0.01 for both).
  
  
  CONCLUSIONS
  Age-related increases of tCr and Ins are found in the PCC, whereas this holds only true for Ins in the HC, indicating possible gliosis in the ageing brain. No age-dependent NAA decreases were observed in the PCC nor the HC. The 1H-MRS results in these specific brain regions can be important to differentiate normal ageing from age-related pathologies such as mild cognitive impairment (MCI) and Alzheimer's disease.
authors.affiliation: Department of Radiology and Nuclear Medicine, Ghent University, and Department of Psychiatry, Ghent University Hospital, Ghent, Belgium. harmen.reyngoudt@ugent.be
authors.forename: Harmen
authors.initials: H
authors.lastname: Reyngoudt
authors.forename: Tom
authors.initials: T
authors.lastname: Claeys
authors.forename: Leslie
authors.initials: L
authors.lastname: Vlerick
authors.forename: Stijn
authors.initials: S
authors.lastname: Verleden
authors.forename: Marjan
authors.initials: M
authors.lastname: Acou
authors.forename: Karel
authors.initials: K
authors.lastname: Deblaere
authors.forename: Yves
authors.initials: Y
authors.lastname: De Deene
authors.forename: Kurt
authors.initials: K
authors.lastname: Audenaert
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Goethals
authors.forename: Eric
authors.initials: E
authors.lastname: Achten
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D007294:Inositol / Q000378:metabolism; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline