APOE 4 and hip fracture risk in a community-based study of older adults.
OBJECTIVE
To investigate whether the APOE 4 allele was associated with increased risk of hip fracture in an older community-based sample and whether such an increased risk was independent of dementia and history of falling.


METHODS
Case-control study nested within a prospective community study.


METHODS
The Monongahela Valley Independent Elders Survey (MoVIES), an ongoing prospective community study of older adults in southwestern Pennsylvania.


METHODS
A total of 899 MoVIES participants (63.9% women; mean age, 76.2 years, SD = 4.9 years), who provided both information on hip fractures and blood samples for genotyping.


METHODS
Interview questions regarding hip fractures and falls, polymerase chain reaction to determine APOE genotype, and clinical assessment using a standardized protocol to determine the presence or absence of dementia.


RESULTS
Twenty-five subjects reported having hip fractures in the year preceding screening interviews. Subjects with one or two APOE 4 alleles were twice as likely as subjects without an APOE 4 allele to report hip fractures (age-adjusted OR = 2.1, 95% CI: 0.9-4.7). Based on multivariate analysis, subjects with a history of falling were more likely to report hip fractures (OR = 4.7, 95% CI: 2.1-10.8). After adjusting for history of falls and diagnosis of dementia, subjects with an APOE 4 allele were still twice as likely to report hip fractures (adjusted OR = 2.1, 95% CI: 0.9 - 4.7).


CONCLUSIONS
The APOE 4 allele appears to be a risk factor for hip fracture, independent of the effect of dementia and falling. Theoretically, this may be mediated by alterations in vitamin K metabolism. Caution should be used in interpreting these results, because the 95% confidence intervals for the odds ratios include 1.
Johnston
J M
JM
NIOSH, Morgantown, WV 26505-2888, USA.
Cauley
J A
JA
Ganguli
M
M
D000058:Accidental Falls; D000367:Age Factors; D000368:Aged; D000483:Alleles; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D003704:Dementia / Q000150:complications; D005260:Female; D005838:Genotype; D015577:Geriatric Assessment; D006620:Hip Fractures / Q000209:etiology* / Q000235:genetics; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012307:Risk Factors; D014812:Vitamin K / Q000378:metabolism
D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D014812:Vitamin K