title: Serum zinc in the progression of Alzheimer's disease.
abstract: Previous studies show significantly decreased levels of zinc transporter 1 (ZnT-1) in the brain of subjects with mild cognitive impairment (MCI) but significantly increased ZnT-1 in late stage AD (LAD). However, the reason for the apparent dichotomy is unclear. Based on in vivo studies that show animals provided a zinc (Zn) deficient diet demonstrate decreased brain ZnT-1, we used inductively coupled plasma-mass spectrometry (ICP-MS) to quantify serum Zn levels from 18 living mild to moderate AD patients (9 men, 9 women), 19 MCI patients (9 men, 10 women) and 16 age-matched normal control (NC) subjects (9 men, 7 women). Zinc levels for all subjects were not significantly different among any of the three subject groups. However, there was a statistically significant decrease of serum Zn (11.7 +/- 0.5 microM) in men with MCI compared to women with MCI (13.7 +/- 0.6 microM) and NC men (13.9 +/- 0.6 microM). Serum Zn levels in probable AD patients were comparable to those in NC subjects. Overall, these data suggest a significant decrease of serum Zn in men with MCI, may explain the loss of ZnT-1 observed in previous studies and suggest there may be more pronounced sex differences in MCI than were previously recognized.
authors.affiliation: Department of Chemistry, University of Missouri, Columbia, MO, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Dong
authors.forename: J David
authors.initials: JD
authors.lastname: Robertson
authors.forename: William R
authors.initials: WR
authors.lastname: Markesbery
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lovell
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood*; D053327:Apolipoprotein E4 / Q000235:genetics; D027682:Cation Transport Proteins / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D012727:Sex Characteristics; D015032:Zinc / Q000097:blood*
chemical_list: D053327:Apolipoprotein E4; D027682:Cation Transport Proteins; C498299:SLC30A1 protein, human; D015032:Zinc