Plasma levels of ApoE and ApoM identify the presence of absence of cognitive decline in alcohol use disorder patients

Abstract

Some apolipoproteins appear to mediate neuroinflammation and cognitive decline in some neuropsychiatric disorders. Whereas APOE has been related to neuroinflammation, neurodegeneration and cognitive decline in Alzheimer's disease (AD) and Alcohol Use Disorder (AUD), APOAI has shown antiinflammatory properties in AD and no data are available in AUD or in cognition. We evaluated the status of plasma APOAI, APOAII, APOB, APOCII, APOE and APOM in abstinent AUD patients, and their influence in associated cognitive decline. 33 abstinent patients with AUD, recruited from an outpatient alcohol program (Hospital Universitario 12 de Octubre, Madrid, Spain) and 34 healthy control subjects were assessed with a validated screening test for AUD, named "Test of detection of cognitive impairment in alcoholism (TEDCA)". The TEDCA identifies the presence of cognitive impairment and provides scores for general intelligence and for three cognitive domains: visuospatial cognition, memory/learning, and executive function. Plasma apolipoproteins were obtained in a time-point between 4 and 12 weeks of abstinence and determined by Enzyme-Linked Immunosorbent Assay (ELISA) kits in all participants. We found a mismatch in plasma APOAI, APOB, APOE, APOJ and APOM levels between patients and controls, being higher in patients (p<0.05), except for APOM, whose levels were lower (p<0.05). APOE and APOM showed the opposite pattern in patients: whereas upregulated APOE correlated with worse cognitive performance explaining the presence of deficit (almost 50%ofdeficit in memory/learning and 52.8% in EF), downregulated APOM correlated with better cognitive scores and was related to the absence of deficit (identifying >50% of the absence of deficit in general intelligence) (logistic regression models). No associations between the other apolipoproteins and cognitive function were observed. Alterations in several plasma apolipoproteins were observed in AUD patients during abstinence. APOE was identified as a possible damaging factor on AUD's cognition whereas APOM. may have a protective role in these patients