A follow-up of 88 patients showed that K-M survival analysis revealed that although mortality rates were higher in patients with POD, there were no significant differences in 3-year survival rates between the high AST/ALT ratio group and the low AST/ALT ratio group.<h4>Conclusion</h4>Preoperative elevation of the serum AST/ALT ratio is a potential risk factor for POD, and its effect may be partially mediated by AD-related CSF biomarkers. Here, GPT is linked to Alzheimer disease.