Patients who have their appendix removed are at greater risk of developing Parkinson’s disease than those who still have their appendix, according to a new study involving more than 62 million patient records from 26 health systems.
The study is the largest to date investigating the link between appendix removal and Parkinson’s disease.
“Recent research into the cause of Parkinson’s has centered around alpha synuclein, a protein found in the gastrointestinal tract early in the onset of Parkinson’s,” said Mohammed Z. Sheriff, M.D., lead author of the study and a physician at Case Western Reserve University and University Hospitals Cleveland Medical Center, Ohio.
“This is why scientists around the world have been looking into the gastrointestinal tract, including the appendix, for evidence about the development of Parkinson’s.”
Previous studies on appendectomies and Parkinson’s have shown contradicting evidence, with some studies showing no link and a recent study from Europe showing patients who still had their appendix as more likely to develop Parkinson’s.
This contradiction prompted Sheriff and colleagues to seek answers to the question using U.S. data from an Ohio-based electronic health records company that draws data from 26 major integrated health systems.
Researchers analyzed the electronic health records of more than 62.2 million patients and identified those who had appendectomies and were diagnosed with Parkinson’s disease at least six months later.
They discovered that among 488,190 patients who had undergone appendectomies, 4,470, or .92 percent, went on to develop Parkinson’s. Of the remaining 61.7 million patients without appendectomies, they identified only 177,230, or .29 percent, who developed the disease.
According to this analysis, patients who’d had their appendix removed were more than three times more likely to develop Parkinson’s than those who had not.
The researchers could not tell from the de-identified records exactly how much time passed after the appendectomy until Parkinson’s was diagnosed. However, they found similar risk levels across all age groups, regardless of gender or race.
“This research shows a clear relationship between the appendix, or appendix removal, and Parkinson’s disease, but it is only an association,” Sheriff said. “Additional research is needed to confirm this connection and to better understand the mechanisms involved.”
Sheriff will present data from the study at Digestive Disease Week (DDW) 2019 in San Diego, Calif.
Source: Digestive Disease Week