Association between memory complaints and incident Alzheimer's disease in elderly people with normal baseline cognition

Objective: Results of previous studies suggest that memory complaints may p redict cognitive decline and dementia among elderly people in whom cognitiv e impairment is already apparent. However, cognitive decline is often a gra dual process, and elderly people may notice that their memory deteriorates before mental status tests are able to detect any change in cognitive funct ioning. Therefore, the authors hypothesized that memory complaints would pr edict incident Alzheimer's disease in elderly subjects with no signs of cog nitive impairment. Method: In the community-based Amsterdam Study of the El derly, a sample of 3,778 nondemented persons, 65 to 84 years old, was selec ted and divided into two cognitive categories: normal (Mini-Mental State sc ores of 26-30) and borderline and impaired (Mini-Mental State scores less t han 26). At baseline, the presence or absence of memory complaints was asse ssed. At follow-up, incident cases of Alzheimer's disease were diagnosed in a two-step procedure. Results: After an average of 3.2 years, 2,169 person s were reevaluated, of whom 77 had incident Alzheimer's disease. Multivaria te logistic regression analyses showed that memory complaints were associat ed with incident Alzheimer's disease in subjects with normal baseline cogni tion but not in subjects with impaired baseline cognition. Conclusions: The findings of this study suggest that memory complaints are a relatively str ong predictor of incident Alzheimer's disease in older persons in whom cogn itive impairment is not yet apparent. Furthermore, they suggest that older persons may be aware of a decline in cognition at a time when mental status tests are still unable to detect a decline from premorbid functioning.