Head injury and risk of Alzheimer's disease by apolipoprotein E genotype.

TitleHead injury and risk of Alzheimer's disease by apolipoprotein E genotype.
Publication TypeJournal Article
Year of Publication1997
AuthorsO'Meara ES, Kukull WA, Sheppard L, Bowen JD, McCormick WC, Teri L, Pfanschmidt M, Thompson JD, Schellenberg GD, Larson EB
JournalAm J Epidemiol
Volume146
Issue5
Pagination373-84
Date Published1997 Sep 01
ISSN0002-9262
KeywordsAged, Aged, 80 and over, Alzheimer Disease, Apolipoproteins E, Craniocerebral Trauma, Female, Genotype, Humans, Logistic Models, Male, Middle Aged, Odds Ratio, Risk, Risk Factors, Unconsciousness, Washington
Abstract

Head injury and apolipoprotein E (APOE)-epsilon 4 (e4) genotype have each been associated with increased risk of Alzheimer's disease. If APOE-e4 affects neuronal viability and branching, and if response to head injury differs in e4 patients, then the association between head injury and Alzheimer's disease may vary with the presence of the e4 allele. The authors examined this association in a case-control study conducted between 1987 and 1995 among enrollees of the Group Health Cooperative of Puget Sound, a health maintenance organization in Seattle, Washington. Proxy informants reported prior head injury with loss of consciousness for 32 of 349 patients with probable Alzheimer's disease and for 16 of 342 control subjects of similar age and sex who had been randomly selected from the same population (odds ratio (OR) = 2.1, 95% confidence interval (CI) 1.1-3.8). Elevated risk was observed among men (OR = 4.2, 95% CI 1.5-11.5) but not among women (OR = 1.1, 95% CI 0.5-2.6). No significant variation in the head injury-Alzheimer's disease risk relation by APOE-e4 genotype was found among 230 cases and 309 controls (OR = 3.1 (95% CI 0.7-14.6) for persons with at least one e4 allele and OR = 2.0 (95% CI 0.8-5.2) for those without e4). Neither age, education, race, type of proxy informant, nor duration of relationship with the proxy confounded the association. Head injury with loss of consciousness, although uncommon in this sample, was associated with increased risk of Alzheimer's disease. APOE-e4 was an independent risk factor which neither modified nor confounded the association. Susceptibility to Alzheimer's disease as conferred by APOE-e4 does not appear to increase the risk associated with head injury.

Alternate JournalAm. J. Epidemiol.
PubMed ID9290497
Grant ListP50 AG05136 / AG / NIA NIH HHS / United States
R01 AG07584 / AG / NIA NIH HHS / United States
U01 AG06781 / AG / NIA NIH HHS / United States