Noncardiac surgeries don’t raise dementia risk, study finds

Elective surgeries aren’t associated with a higher rate of dementia among older adults, according to a new study published Jan. 2 in the Journal of the American Geriatrics Society.

Those who underwent surgery had a 12% lower rate of dementia compared to people they were matched with who didn’t have an operation. The association remained the same in adjusted data.

Researchers wanted to see if there was a link between undergoing surgery and developing dementia. Some evidence suggests that neurocognitive decline after an operation is from neuroinflammation, neuron damage and the increased risk for vascular disorders. Some experts think older adults have a lower ability to recover from neuroinflammatory activity, leading to the chronic inflammation that could drive neurodegenerative disorders including dementia.

A team of investigators used data from Canada on 27,878 people 66 and up who underwent elective surgeries between 2007 and 2011. The participants were matched to controls who had a visit with a doctor of the same surgical specialty (were diagnosed with the same ailment) but didn’t have surgery; a total of 13,939 pairs were evaluated. Elective surgeries were classified as those that were booked ahead of time and completed at a later date, even if it was medically recommended or necessary procedure.

After a five year follow-up period, the team looked at which people were diagnosed with dementia. The surgeries were noncardiac operations, meaning they didn’t include procedures such as putting in a stent or removing a blockage from the heart. The surgeries that the researchers included were hip replacement, knee replacement, inguinal hernia repair, prostatectomy and hysterectomy.

“These results can be generalized to many older adults and provide reassurance to clinicians and surgeons that older adults undergoing common surgical procedures do not have an elevated rate of developing dementia compared with their nonsurgical counterparts with similar surgical indications,” the authors wrote. “This study will help guide discussions around surgical decision-making and aid in informed decision-making around long-term cognitive outcomes in older adults considering elective surgical interventions.”