Interaction between Alcohol Use Disorder, APOE4 and Cognitive Decline in patients undergoing an alcohol detoxification program

ApoE genotype has been related to alcohol consumption and cognition, in fact, individuals bearing allele 4 (APOE4+) are distinguished from those without it (APOE4-) by having an increased vulnerability to alcohol-induced neurotoxicity, indirectly influencing cognition. The influence of APOE4+ on domain-specific cognitive impairment in AUD patients remains unclear.

24 abstinent patients with Alcohol Use Disorder (AUD) recruited from an outpatient alcohol program in Hospital Universitario 12 de Octubre (Madrid, Spain) and 34 healthy control subjects were tested using a battery of neuropsychological tests specific to AUD and named 'Test of detection of cognitive impairment in alcoholism (TEDCA)'. The TEDCA identifies the presence of cognitive impairment (GCF) and three cognitive dimensions: Visuospatial Cognition, Memory/Learning and Executive Function (EF). Blood extractions from all participants allowed obtain plasma in which APOE4 was determined by e4Quant patented technique, using the chemistry analyzer KROMA-PLUS. Statistical analysis was performed through IBM SPSS.

Multiple analyses of covariance (ANCOVA) with group (patients and controls) and APOE4 (APOE4+ or APOE4-) as factors revealed a main effect of group for all domains (with lower cognition scores in patients), a main effect of APOE4 on GCF, Memory/Learning, and EF (p < 0.05) (with lower cognition scores in APOE4+) and an interaction between APOE4xgroup on Memory/Learning (p < 0.05), so that the difference between APOE4+ and APOE4- carriers was greater in the alcohol group.

The negative effect of the presence of APOE4 is different between patients and controls only for the Memory/Learning domain. The co-presence of AUD and APOE4+ may favour cognitive impairment in this specific domain.