Elderly people who have a gene associated with increased risk of late-onset Alzheimer’s disease and other types of dementia also might be predisposed to delirium after major surgery, new research suggests.

Postoperative delirium can result in higher rates of nursing home placement and increased rates of in-hospital death, the researchers said. Study subjects with the apolipoprotein E (APOE) e4 gene variant were nearly four times more likely to develop postoperative delirium compared with those without the gene, with results weighted to account for certain variables, researchers at the University of California-San Francisco reported.

Investigators analyzed 190 patients with an average age of 73 and found that nearly 28 % of patients with the APOE e4 developed postoperative delirium gene, compared with 11% of those without APOE. The study was published in the journal Anesthesiology.