Liver Health and Dementia in an Italian Older Population: Findings From the Salus in Apulia Study

Abstract

Objectives: Non-alcoholic fatty liver disease (NAFLD) currently affects a quarter of the global population. Systemic inflammation, metabolic syndrome, and coronary artery disease, all conditions associated with NAFLD, have also been related to cognitive dysfunction in older age. The present study aimed to investigate the relationship between NAFLD risk and a dementia diagnosis in a large population-based sample aged > 65 years.Methods: We selected 1,542 participants (723 men) from the Salus in Apulia Study. To assess the risk of fat distribution in the liver, we used the Fatty Liver Index (FLI). Dementia was diagnosed according to the American Psychiatric Association criteria (DSM-5).Results: The overall prevalence of dementia was 8.5% [95% confidence interval (CI): 7–10%]. Subjects with dementia were older [effect size (ES): −0.89, 95% CI: −1.07 to −0.70], had a lower level of education (ES:0.88, 95% CI:0.69–1.06), higher levels of gamma-glutamyl transferase (ES: −0.21, 95% CI: −0.39 to −0.03), lower levels of total cholesterol (ES: −0.24, 95% CI: −0.42 to −0.06) and low-density lipoprotein cholesterol (ES: −0.20, 95% CI: −0.38 to 0.02), and a higher FLI (ES: −0.22, 95% CI: −0.39 to −0.04). In the logistic regression model adjusted for age, sex, education, hypertension, diabetes mellitus, alcohol consumption, smoking habits, stroke, cholesterol, and Apo-E, a dementia diagnosis was positively associated with FLI > 60 [odds ratio (OR):1.81; standard error (SE): 0.53; 95% CI: 1.02–3.21].Conclusion: Our findings suggested that an increased NAFLD risk may be associated to dementia and cognitive decline in older age. Considering the high NAFLD prevalence, the possible adverse disease effects on cognitive performance pose a health problem with significant social and economic implications.

Risk of dementia or cognitive impairment in non-alcoholic fatty liver disease: A systematic review and meta-analysis

“…Of these 9 articles, 8 failed to provide relevant data and outcomes and 1 article provided incomplete data. Ultimately, 7 studies (Labenz et al, 2021 ; Lampignano et al, 2021 ; Shang et al, 2021 ; Jeong et al, 2022 ; Kim et al, 2022 ; Liu et al, 2022 ; Yu et al, 2022 ) were included in this study. The search selection process is presented in Figure 1 .…”

“…Seven studies were included in this review. Five studies (Labenz et al, 2021 ; Shang et al, 2021 ; Jeong et al, 2022 ; Kim et al, 2022 ; Liu et al, 2022 ) were cohort studies and 2 studies (Lampignano et al, 2021 ; Yu et al, 2022 ) were case–control studies. The 7 studies were published from 2020 to 2022 and involved a total of 891,562 individuals, with sample sizes ranging from 1542 to 608,994 individuals per study.…”

“…As shown in Figures 4, 5 studies (Labenz et al, 2021;Lampignano et al, 2021;Shang et al, 2021;Jeong et al, 2022;Kim et al, 2022;Liu et al, 2022;Yu et al, 2022) described the association of all-cause dementia with NAFLD; however, results from the data showed that the relationship between NAFLD and an increased risk of all-cause dementia was not obvious (OR = 1.03; 95% CI: 0.97-1.09; I 2 = 84.7%; P = 0.341). Since Alzheimer Disease (AD) and vascular dementia (VD) belong to the category of dementia, we extracted the data of AD and VD separately for reanalysis.…”

Shared Risk Factors between Dementia and Atherosclerotic Cardiovascular Disease

“…NAFLD is the most common cause of chronic liver disease in Western countries [ 90 ]. Many risk factors have been associated with cardiovascular disease [ 91 ], but only a few studies have investigated the association between NAFLD and a risk of dementia.…”

“…In a study by Lampignano et al from 2021, they found that an index score developed to predict the risk of NAFLD was associated with a higher risk of all-cause dementia [ 90 ]. Another study that included 646 NAFLD cases did not find an association between NAFLD and a risk of dementia, however, when integrating fibrosis stage in a risk prediction model with conventional risk factors, they found an improved prediction of dementia risk [ 94 ].…”