Interaction between apolipoprotein E genotypes, excessive daytime sleepiness, and cognitive function in obstructive...

Area of Science:

• Neuroscience
• Genetics
• Sleep Medicine

Background:

• Obstructive sleep apnea syndrome (OSAS) is linked to the apolipoprotein E ε4 allele (ApoEε4) and excessive daytime sleepiness (EDS).
• Limited research exists on the interplay between EDS, cognitive function, and ApoEε4 in OSAS patients.

Purpose of the Study:

• To investigate the cognitive performance of adults with and without EDS.
• To assess the influence of the ApoEε4 genotype on cognitive function in relation to EDS.

Main Methods:

• 21 adult patients (33-79 years) underwent clinical interviews, ApoE genotyping, and polysomnography.
• Neuropsychological evaluations and the Epworth Sleepiness Scale were used to assess cognitive function and sleepiness.

Main Results:

• EDS correlated with lower IQ and poorer immediate visual memory, irrespective of ApoE genotype.
• ApoEε3/ε4 carriers showed deficits in divided attention, constructional praxis, perceptual organization, and cognitive flexibility.
• The combination of the ε4 allele and EDS exacerbated cognitive decline, particularly affecting processing speed, selective attention, and visuomotor coordination.

Conclusions:

• Both EDS and the ApoEε3/ε4 genotype are independently associated with reduced cognitive performance in OSAS.
• The synergistic effect of EDS and the ε4 allele significantly potentiates cognitive impairment in these patients.