Odor identification deficit as a predictor of five-year global cognitive change: interactive effects with age and ApoE-epsilon4.
Olfactory impairments are present in common neurodegenerative disorders and predict conversion to dementia in non-demented individuals with cognitive impairment. In cognitively intact elderly, evidence is sparse regarding the role of olfactory deficits in predicting cognitive impairment. The present study investigated predictors of 5-year prospective decline in the Mini-Mental State Examination (MMSE) in a large (n = 501), population-based sample of elderly (65-90 years) individuals. All participants were genotyped for the ApoE gene, assessed for health factors, and were non-demented at the baseline assessment. After partialling out the influences of demographic and health-factors at baseline and dementia at follow-up, poor odor identification ability in combination with older age and the ApoE-epsilon4 allele predicted larger prospective global cognitive decline. This effect could not be produced by a vocabulary test. In sum, the findings suggest that an olfactory deficit can dissociate between benign and malign global cognitive development in non-demented, very old epsilon4-carriers, who are at high risk of developing dementia.
Olofsson
Jonas K
JK
Department of Psychology, Umeå University, Umeå, Sweden. jonas.olofsson@psychology.su.se
Rönnlund
Michael
M
Nordin
Steven
S
Nyberg
Lars
L
Nilsson
Lars-Göran
LG
Larsson
Maria
M
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001057:Apolipoproteins E / Q000235:genetics*; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000235:genetics*; D003704:Dementia / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D009812:Odorants; D000857:Olfaction Disorders / Q000175:diagnosis / Q000235:genetics*; D012903:Smell / Q000235:genetics*
D001057:Apolipoproteins E