Unpicking the genetics of postoperative delirium

The genetic variations that might make someone more likely to experience postoperative delirium are explored in a new Bristol Biomedical Research Centre (BRC) paper published in PLOS Medicine.

Researchers from the BRC’s Translational Data Science Theme performed a genome-wide association study or GWAS. This type of study uses genetic datasets, in this case the UK Biobank, to map variants across the genomes of large numbers of people.

Delirium following a major operation is the most common postoperative complication among older people. However, not much is known about how genes affect postoperative delirium. Understanding the genetic risk factors could help with treatment and prevention in the future.

The team wanted to understand the links between an individual’s genes and their likelihood of experiencing postoperative delirium. They also wanted to explore genetic similarities between postoperative delirium, general delirium and Alzheimer’s disease.

They reviewed the genes of 1,016 people who had experienced postoperative delirium, comparing them with those of 139,148 people who hadn’t. This revealed:

• Postoperative delirium has shared biology with Alzheimer’s disease, and may be a sign of its early stages
• People with a genetic risk for Alzheimer’s disease have an increased risk of postoperative delirium and vice versa

This link between postoperative delirium and Alzheimer’s complements findings from other recent large-scale studies looking at delirium in general and Alzheimer’s.

However, the team found a relatively small number of cases in the dataset and may have missed some other cases. This means they were unable to detect small or modest genetic effects in this study.

Richard Armstrong, Wellcome GW4 Clinical Doctoral Fellow and lead author of the study, said:

“As postoperative delirium is so common, we felt it was an important issue to explore genetically. Our findings reinforce other similar work, but need to be further validated with a larger dataset.

“We hope that this study paves the way for further research. Ultimately this would improve our ability to predict a patient’s likelihood of postoperative delirium and earlier identification of Alzheimer’s risk.”