APOE Polymorphism, Obstructive Sleep Apnea, and Cognitive Function.
Level 4 - case-series / case-control
Cross-sectional observational study comparing cognitive outcomes across OSA severity and APOE genotype groups.
PubMed 40292207 · doi:10.1055/s-0044-1788286
What was done
Evaluated 55 middle-aged, sedentary patients with no other major comorbidities. Participants completed nocturnal polysomnography, APOE ε4 polymorphism genotyping, physical activity assessment via the International Physical Activity Questionnaire, and cognitive testing covering attention, inhibitory control, frontal functions, processing speed, and episodic memory. Comparisons were made between individuals with no/mild OSA versus moderate-to-severe OSA (apnea-hypopnea index ≥ 15 events/h), and between APOE ε4 carriers and non-carriers.
What was found
Thirteen patients had no or mild OSA (7.7% APOE ε4 carriers) and 42 had moderate-to-severe OSA (21.4% APOE ε4 carriers). Within the moderate-to-severe OSA group, sleep parameters were similar between APOE ε4 carriers and non-carriers. Patients with moderate-to-severe OSA performed worse on processing speed (Digit Symbol Test) and attention (Stroop Color Word Test, SCWT-Part 2) than those with no/mild OSA, a difference that remained after excluding APOE ε4 carriers. Among moderate-to-severe OSA patients, APOE ε4 carriers exhibited worse episodic memory (Rey Auditory Verbal Learning Test) than non-carriers. Absolute test scores, effect sizes, and p-values were not provided in the abstract.
Why it matters
This study suggests that while moderate-to-severe OSA impairs attention and processing speed independently of genotype, carrying the APOE ε4 allele may selectively exacerbate episodic memory deficits in these patients.
Limits
The total sample was very small (n=55), resulting in very few APOE ε4 carriers and limited statistical power. The cross-sectional design cannot determine longitudinal trajectory or causality. Restricting the cohort to sedentary individuals without major comorbidities limits generalizability to typical clinical OSA populations.
Cited by
- supports Individuals carrying the APOE4 allele have a significantly elevated risk of developing sleep apnea.