GPT and dementia: Damage to liver cells leads to the release of both enzymes but as the liver function declines further, the AST clearance rate also reduces leading to higher levels as compared to ALT.42 Furthermore, AST is also found in other areas like skeletal muscles, the heart, brain while ALT is exclusively a liver-specific enzyme.11 The ratio of AST:ALT also called as De Ritis ratio is routinely used to examine liver function and the severity of liver damage.43 A high ratio was associated with both cognitive impairment and dementia in our meta-analysis.