Apolipoprotein epsilon4 is associated with more rapid decline in odor identification than in odor threshold or Dementia Rating Scale scores

Brain Cogn. 2005 Jul;58(2):178-82. doi: 10.1016/j.bandc.2004.10.004. Epub 2004 Dec 7.


Individuals with the apolipoprotein E epsilon4 genetic risk factor for Alzheimer's disease (AD) show deficits in olfactory function. The purpose of the present study was to examine longitudinally odor identification (odor ID), odor threshold, picture identification, and global cognitive status in allele positive (epsilon4+) and negative (epsilon4-) persons. Participants were initially given the San Diego Odor Identification test, an odor threshold test, and the Dementia Rating Scale (DRS). Participants were re-tested approximately four years later. The results indicate: (1) odor ID declined more rapidly in epsilon4+ than in epsilon4- normal elderly adults; (2) neither group exhibited a significant decline in odor threshold, picture identification or DRS scores. These results suggest that declines in odor identification occur before declines in other measures of dementia in persons at risk for AD because of their APOE allele genetic status.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Alleles*
  • Alzheimer Disease / epidemiology*
  • Alzheimer Disease / genetics
  • Alzheimer Disease / metabolism*
  • Apolipoproteins E / genetics
  • Apolipoproteins E / metabolism*
  • Cognition Disorders / diagnosis
  • Differential Threshold / physiology
  • Female
  • Genotype
  • Humans
  • Male
  • Odorants*
  • Olfaction Disorders / diagnosis
  • Olfaction Disorders / epidemiology*
  • Risk Factors
  • Severity of Illness Index
  • Surveys and Questionnaires*
  • Time Factors


  • Apolipoproteins E