<b>Objective</b>: In the present study, we test the robustness of the association between IGF-I receptor stimulating activity and dementia by extending the follow-up period to 16 years and investigate possible effect modification by apolipoprotein E (ApoE).
566 pathologically-confirmed AD cases who were followed prospectively with antemortem dementia diagnoses (312 ApoE ϵ4 carriers and 254 ApoE ϵ4 non-carriers) were compared on the frequencies of neuropathological frequency scores (none, sparse, moderate, frequent) among several different brain regions (frontal, temporal, parietal, hippocampal, and entorhinal) using the CERAD scoring system.
Dementia incidence was associated with increasing age in both normal and cognitively impaired participants; however, an APOE4 allele was associated with a higher dementia incidence only in participants with baseline cognitive impairment.
Apolipoprotein E (APOE) epsilon4 gene dose (i.e., the number of epsilon4 alleles in a person's APOE genotype) is associated with a higher risk of AD and a younger age at dementia onset.
APOE genotype, age of onset, disease duration, smoking history, and dementia status were collected for families with PD, yielding 324 Caucasian families with complete information.
APOE epsilon4 constitutes a risk factor for dementia, mild injury in isolation does not increase the risk, but head injury in combination with the APOE epsilon4 leads to increased risk of dementia.