AST/ALT ratios were significantly higher in patients with pneumonia relative to non-pneumonia patients (P<0.001) and in those with delirium versus those with no delirium (P<0.01); compared with the low AST/ALT group, the high AST/ALT group had a higher prevalence of pneumonia (21.90% vs. 11.06%, P<0.01) and delirium (20.44% vs. 11.54%, P<0.05). The gene discussed is GPT; the disease is susceptibility to pneumonia measurement.