People who have their appendix removed are three time more likely to develop Parkinson’s disease, warns new research.
The largest ever study of the relationship between the gut and the debilitating nervous system disorder involved the analysis of more than 62 million patients records.
Researchers found that patients who had their appendix removed were more likely to develop Parkinson’s than those whose appendix remained in place.
Study lead author Dr Mohammed Sheriff, a physician at Case Western Reserve University and University Hospitals Cleveland Medical Centre in the US, said: “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.
“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.”
He said previous findings on appendectomies and Parkinson’s have been inconsistent, with some studies showing no relationship and a recent study showing patients who still had their appendix were more likely to develop Parkinson’s.
The contradiction prompted Dr. 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.
The researchers analysed electronic health records representing more than 62.2 million patients and identified those who had appendectomies and were diagnosed with Parkinson’s at least six months later.
They found that among 488,190 patients who had undergone appendectomies, 4,470 (0.92 per cent), went on to develop Parkinson’s.
Of the remaining 61.7 million patients without appendectomies, they identified only 177,230 (0.29 per cent) who developed the disease.
According to the analysis, patients who had an appendectomy were more than three times as likely to develop Parkinson’s than those who had not.
The research team found similar risk levels across all age groups, regardless of gender or race.
Dr Sheriff added: “This research shows a clear relationship between the appendix, or appendix removal, and Parkinson’s disease, but it is only an association.
“Additional research is needed to confirm this connection and to better understand the mechanisms involved.”
The findings are due to be presented at the Digestive Disease Week annual conference in California later this month.