APOE ε4 lowers age at onset and is a high risk factor for Alzheimer's disease; A case control study from central Norway
2008

APOE ε4 and Alzheimer's Disease Risk in Norway

Sample size: 937 publication 10 minutes Evidence: high

Author Information

Author(s): Sigrid B. Sando, Stacey Melquist, Ashley Cannon, Michael L. Hutton, Olav Sletvold, Ingvild Saltvedt, Linda R. White, Stian Lydersen, Jan O. Aasly

Primary Institution: Norwegian University of Science and Technology (NTNU)

Hypothesis

Does the APOE ε4 allele influence the risk and age of onset for Alzheimer's disease in central Norway?

Conclusion

The APOE ε4 allele is a strong risk factor for Alzheimer's disease in central Norway and significantly lowers the age at onset of late-onset Alzheimer's disease.

Supporting Evidence

  • Carriers of the APOE ε4 allele had an odds ratio of 12.9 for developing Alzheimer's disease.
  • The age at onset for Alzheimer's disease decreased by about three years for each APOE ε4 allele carried.
  • 64.1% of Alzheimer's patients carried one or more APOE ε4 alleles compared to 26.4% of controls.

Takeaway

If you have a specific gene called APOE ε4, you are more likely to get Alzheimer's disease and will likely get it at a younger age.

Methodology

The study involved genotyping 376 Alzheimer's patients and 561 cognitively-normal controls to compare allele frequencies and calculate odds ratios.

Potential Biases

Potential selection bias due to the recruitment of controls from specific populations.

Limitations

The study's control group was selected to exclude individuals with known dementia in first-degree relatives, which may affect the generalizability of the results.

Participant Demographics

Participants included 376 Alzheimer's patients (263 women, 113 men) and 561 cognitively-normal controls (338 women, 223 men), all ethnic Norwegians.

Statistical Information

P-Value

< 0.001

Confidence Interval

95% CI for ORs varies by genotype

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1186/1471-2377-8-9

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