Risk of dementia associated with the ApoE epsilon4 allele and falls causing head injury without explicit traumatic brain injury.
OBJECTIVE
Severe head injury (HI) and the apolipoprotein E (ApoE) epsilon4 allele are risk factors for dementia. The corresponding effect of falls causing HI without explicit traumatic brain injury (TBI) in association with the ApoE epsilon4 is not known.


METHODS
Altogether 134 persons aged 70 years or older constituted a retrospective population sample, who scored > or =26 in the MiniMental State Examination (MMSE) test at baseline and were clinically examined for dementia 9 years afterward. Fall-related HI causing superficial laceration or bruises or wounds that require suturing were prospectively recorded during the 9-year follow-up. We used Cox regression with age at the diagnosis of dementia as a dependent variable.


RESULTS
Twenty-eight (21%) subjects had falls causing HI without explicit TBI, the ApoE epsilon4 allele was seen in 44 (33%), and clinical dementia was diagnosed in 25 (19%). Adjusted for the baseline MMSE score, sex and educational status, the hazard ratio for subsequent dementia in subjects having falls with HI without explicit TBI and the ApoE epsilon4 allele as compared with those who do not possess these characteristics was 2.70 (95% confidence interval, 1.02-7.16).


CONCLUSIONS
According to the results of this small retrospective study, falls with HI without explicit TBI in connection with the ApoE epsilon4 allele is associated with subsequent dementia among older adults.
Luukinen
H
H
Department of Public Health Science and General Practice, University of Oulu, Unit of General Practice, Oulu University Hospital, Oulu, Finland. heikki.luukinen@oulu.fi
Jokelainen
J
J
Kervinen
K
K
Kesäniemi
Y A
YA
Winqvist
S
S
Hillbom
M
M
D000058:Accidental Falls; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics*; D001930:Brain Injuries / Q000453:epidemiology; D006259:Craniocerebral Trauma / Q000453:epidemiology* / Q000235:genetics; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors
D053327:Apolipoprotein E4