Odor identification impairment in carriers of ApoE-ɛ4 is independent of clinical dementia

Olofsson, Jonas K.; Nordin, Steven; Wiens, Stefan; Hedner, Margareta; Nilsson, Lars-Göran; Larsson, Maria

doi:10.1016/j.neurobiolaging.2008.05.019

« Previous Next »Neurobiology of Aging
Volume 31, Issue 4 , Pages 567-577, April 2010

Odor identification impairment in carriers of ApoE-ɛ4 is independent of clinical dementia

Jonas K. Olofsson
- Department of Psychology, Umeå University, Umeå, Sweden
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Stockholm Brain Institute, Stockholm, Sweden
- Corresponding author. Present address: Department of Psychology, Stockholm University, SE-106 91 Stockholm, Sweden. Tel.: +46 8 163834; fax: +46 8 159342.
Steven Nordin
- Department of Psychology, Umeå University, Umeå, Sweden
- Department of Psychology, San Diego State University, San Diego, USA
Stefan Wiens
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Stockholm Brain Institute, Stockholm, Sweden
Margareta Hedner
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Stockholm Brain Institute, Stockholm, Sweden
Lars-Göran Nilsson
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Stockholm Brain Institute, Stockholm, Sweden
Maria Larsson
- Department of Psychology, Stockholm University, Stockholm, Sweden
- Stockholm Brain Institute, Stockholm, Sweden

Received 24 October 2007; received in revised form 7 May 2008; accepted 20 May 2008. published online 11 July 2008.

Abstract

The ApoE gene is expressed in olfactory brain structures and is believed to play a role in neuronal regenerative processes as well as in development of Alzheimer's disease (AD), the most common form of dementia. The ɛ4 allele has been reported to be associated with compromised odor identification ability in the elderly, and this deficit has been interpreted as a sign of pre-diagnostic AD. However, because it has not been demonstrated that the relationship between the ɛ4 allele and odor identification is mediated by dementia, it is possible that the ɛ4 allele may have an effect on odor identification over and above any effects of dementia. The present study investigated effects of ApoE-status on odor identification in a large, population-based sample (n=1236) of adults (45–80 years), who were assessed for dementia at time of testing and 5 years later. The results showed that the ɛ4 allele was associated with an odor identification deficit among elderly participants (75–80). Critically, this effect remained after current and pre-diagnostic dementia, vocabulary, global cognitive status and health variables were partialled out. The present results suggest that the ApoE gene plays a role in olfactory functioning that is independent of dementia conversion within 5 years.