Apolipoprotein E (APOE) ε4 Status Moderates the Relationship Between Close-Range Blast Exposure and Cognitive...

Area of Science:

• Neuroscience
• Genetics
• Military Medicine

Background:

• Close-range blast exposure (CBE) may cause long-term cognitive deficits, with outcomes varying significantly among individuals.
• The apolipoprotein (APOE) ε4 allele, a known risk factor for Alzheimer's disease, is investigated as a potential factor influencing this variability.
• Understanding genetic predispositions is crucial for assessing the long-term cognitive impact of neurotrauma.

Purpose of the Study:

• To investigate whether apolipoprotein (APOE) ε4 carrier status moderates the long-term cognitive effects of close-range blast exposure (CBE).
• To determine if APOE ε4 status influences cognitive outcomes in veterans following military service involving blast exposure.

Main Methods:

• Neuropsychological assessments were conducted on 488 post-9/11 veterans with documented blast exposure history.
• Data included cognitive functioning, psychiatric diagnoses, history of mild traumatic brain injuries (mTBIs), and apolipoprotein (APOE) ε4 genotypes.
• Cognitive performance (attention, memory, executive function) was analyzed in relation to CBE and APOE ε4 status.

Main Results:

• APOE ε4 carriers exposed to CBE showed significantly poorer performance in memory compared to non-carriers.
• These findings remained significant after adjusting for clinical, demographic, and other genetic factors.
• Similar trends were observed for other neurotrauma variables, but the effect was specific to CBE and APOE ε4 status.

Conclusions:

• Individuals carrying the APOE ε4 allele are more susceptible to the cognitivedetrimental effects of close-range blast exposure.
• Genetic risk factors, particularly APOE ε4 status, should be considered in research and clinical evaluations of cognitive health following neurotrauma.
• This study underscores the importance of personalized approaches in understanding and managing the long-term consequences of blast-related injuries.