Appendectomy linked to increased risk of Parkinson's disease, finds a study

Appendectomies are associated with an increased risk of Parkinson's disease revealed a large, population-based, epidemiological study.

Parkinson's disease (PD) is a neurodegenerative disorder that affects predominately dopamine-producing ("dopaminergic") neurons in a specific area of the brain called substantia nigra. Prior studies have suggested that appendectomy may modify the emergence of Parkinson's disease (PD) by affecting the retrograde transport of α-synuclein (α-syn) from the gastrointestinal system. Parkinson's disease signs and symptoms can be different for everyone. Early signs may be mild and go unnoticed.

The present study was conducted to investigate if appendectomies increase the risk of Parkinson's disease, in a large population-based commercial database.

The database used by the investigators was Explorys Inc which contains electronic health records from 26 major integrated US healthcare systems. We identified patients who underwent appendectomies and those who were diagnosed with Parkinson's disease based on Systemized Nomenclature of Medicine - Clinical Terms. We chose a washout period of 6 months to the development of Parkinson's disease after appendectomies. We compared the prevalence of Parkinson's disease in the general population to those with appendectomies.

Of the 62,218,050 in the database, they identified 488,190 patients who underwent appendectomies. A total of 4470 cases of Parkinson's disease were observed in patients with appendectomies, and 177,230 cases of Parkinson's disease in patients without appendectomies. The overall Relative Risk of developing Parkinson's disease in patients after appendectomies were compared to those who did not undergo the procedure. Patients aged 18-64 and those aged ≥ 65 both had an increased risk of developing Parkinson's disease. As demonstrated, Caucasians, African Americans, and Asians were at an increased risk of Parkinson's disease after appendectomies.

The investigators concluded that appendectomies increase the risk of Parkinson's disease in this large, population-based, epidemiological study. This increase in risk occurs over all age groups, and regardless of gender or race. One limitation of the study to note is while a washout period was conducted, the time after appendectomy to the development of PD cannot be determined from the database.

The study PARKINSON'S DISEASE IS MORE PREVALENT IN PATIENTS WITH APPENDECTOMIES: A NATIONAL POPULATION-BASED STUDY will be presented during Digestive Disease Week (DDW) 2019, May 18-21 in San Diego, California.