Cognitive impairment and liver fibrosis in non-alcoholic fatty liver disease.

Background: Data regarding the prevalence and phenotype of cognitive impairment in non-alcoholic fatty liver disease (NAFLD) are limited. Objective: We assessed the prevalence and nature of cognitive deficits in people with NAFLD and assessed whether liver fibrosis, an important determinant of outcomes in NAFLD, is associated with worse cognitive performance. Methods: We performed a prospective cross-sectional study. Patients with NAFLD underwent liver fibrosis assessment with transient elastography and the following assessments: Cognitive Change Index, Eight-Item Informant Interview to Differentiate Aging and Dementia Questionnaire (AD8), Montreal Cognitive Assessment (MoCA), EncephalApp minimal hepatic encephalopathy test and a limited National Institutes of Health Toolbox battery (Flanker Inhibitory Control and Attention Test, Pattern Comparison Test and Auditory Verbal Learning Test). We used multiple linear regression models to examine the association between liver fibrosis and cognitive measures while adjusting for relevant covariates. Results: We included 69 participants with mean age 50.4 years (SD 14.4); 62% were women. The median liver stiffness was 5.0 kilopascals (IQR 4.0-6.9), and 25% had liver fibrosis (≥7.0 kilopascals). Cognitive deficits were common in people with NAFLD; 41% had subjective cognitive impairment, 13% had an AD8 >2, 32% had MoCA <26 and 12% had encephalopathy detected on the EncephalApp test. In adjusted models, people with liver fibrosis had modestly worse performance only on the Flanker Inhibitory Control and Attention Task (β=-0.3; 95% CI -0.6 to -0.1). Conclusion: Cognitive deficits are common in people with NAFLD, among whom liver fibrosis was modestly associated with worse inhibitory control and attention.