Effects of ε4 on object recognition in the non-demented elderly

Previously we reported that Apolipoprotein E (ApoE) 4 negatively affects performance in the novel-image-novel-location (NINL) object recognition test in healthy non-demented elderly human study participants. In this study, the participants were invited to return for testing sessions 6 and 18 months after the baseline session. Using a longitudinal study design, effects of 4 on NINL test performance were assessed in study "dropouts", participants that did not return for the second and/or third session(s), and "finishers", participants that returned for all sessions. There were effects of 4 on dropout rates and NINL total scores as well as sub-scores in both dropouts and finishers. NINL total score was a predictor of 4 participant dropout. Compared to non- 4 dropouts, 4 dropouts had lower NINL scores. In contrast, 4 finishers had higher NINL scores than non- 4 finishers. Thus, the NINL test could be a valuable tool in detecting preclinical signs of age-related cognitive impairments, particularly those associated with 4 risk.