Effects of sex and APOE ε4 on object recognition and spatial navigation in the elderly

To determine effects of APOE ε4 (ε4) on cognitive performance of healthy elderly, 116 nondemented elders (mean age 81 years) were cognitive tested. The established tests Faces, Family Pictures, Spatial Span Forward and Backward, and the object recognition and spatial navigation tests developed in our laboratory were used as cognitive tests. Salivary samples were collected to determine APOE genotype and salivary testosterone and cortisol levels. Non-ε4- and ε4-carrying men and women did not differ in age, Mini-Mental State Examination, Wide Range Achievement Test-Reading, Beck Anxiety Inventory, or reaction time scores. There was an effect of ε4 on the object recognition and spatial navigation tests, with non-ε4 carriers outperforming ε4 carriers, but not in the other cognitive tests. No relationship was found for sex and ε4 status or sex and performance during the hidden session of Memory Island. In men, salivary cortisol levels correlated with object recognition. These results show that object recognition and spatial navigation tests are useful to assess cognitive function in the elderly.