Will testing for apolipoprotein E assist in tailoring dementia risk reduction? A review

Area of Science:

• Neuroscience
• Genetics
• Public Health

Background:

• Dementia risk is influenced by modifiable lifestyle factors.
• Apolipoprotein E (ApoE) genotype is a known genetic risk factor for dementia.
• Understanding gene-environment interactions is crucial for dementia prevention.

Purpose of the Study:

• To systematically review how apolipoprotein E (ApoE) influences the impact of mid and late-life risk factors on dementia.
• To synthesize evidence on gene-environment interactions in dementia etiology.

Main Methods:

• Systematic literature search of Scopus, Medline, PubMed, PsycINFO, and HuGE databases up to November 2008.
• Selection of 94 relevant articles by two independent reviewers from over 13,000 initial results.
• Analysis of ApoE's modifying role on various dementia risk factors.

Main Results:

• Smoking's negative impact on dementia risk appears limited to individuals without the ApoE epsilon 4 variant.
• The ApoE epsilon 4 variant increases dementia risk with higher fat consumption, especially saturated fats.
• ApoE epsilon 4 enhances the protective effect of hormone replacement therapy (HRT) against dementia.
• ApoE does not appear to modify dementia risk associated with cardiovascular disease (CVD) factors, other diets, or estradiol.
• Evidence for other environmental factors and ApoE interaction was inconsistent.

Conclusions:

• Apolipoprotein E genotype modifies the influence of specific lifestyle factors on dementia risk.
• Current evidence does not support routine ApoE testing for tailoring dementia risk reduction.
• Further research is needed to clarify ApoE's role in dementia prevention strategies.