# Association between liver biomarkers and risk of cognitive impairment and dementia: A systematic review and meta-analysis

## TL;DR

This study finds that certain liver biomarkers, like GGT and AST:ALT ratio, may predict cognitive impairment and dementia risk.

## Contribution

The study provides new evidence on the association between specific liver biomarkers and cognitive decline.

## Key findings

- Higher AST:ALT ratio and GGT levels are linked to increased cognitive impairment risk.
- Lower ALT levels are associated with a higher risk of dementia.
- ALT and AST levels alone show no significant association with cognitive impairment.

## Abstract

We aimed to systematically examine the literature and conduct a meta-analysis to assess if liver biomarkers like alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT) could be predictors of cognitive impairment and dementia.

Online databases of Scopus, Embase, PubMed, CENTRAL, and Web of Science were searched for all observational studies examining the research question. The last date of the search was August 20, 2024.

We selected 13 studies. Pooled analysis showed that there was no significant association between ALT levels or AST levels and risk of cognitive impairment. Meta-analysis showed the higher AST: ALT ratio and higher GGT levels were associated with a statistically significant increased risk of cognitive impairment. Lower ALT levels were associated with a significant increase in the risk of dementia but no significant association was noted with AST or GGT levels.

Preliminary evidence indicates that liver biomarkers may have a role in predicting the risk of cognitive impairment/dementia. A high AST: ALT ratio may be linked with an increased risk of cognitive impairment and dementia. Likewise, high GGT and low ALT levels seem to be associated with increased risk of cognitive impairment and dementia respectively.

PROSPERO Registration Number: CRD42024579967.