• Posted August 25, 2023

Gut Troubles Could Be Early Signal of Parkinson's Disease

It might not seem like constipation or difficulty swallowing could signal a neurological problem, but new research suggests that these gut conditions could be an early indicator of Parkinson's disease.

Gastrointestinal symptoms are also thought to precede the development of cerebrovascular disease, including stroke, brain aneurysm or Alzheimer's disease. It has previously been suggested that gut conditions may appear before Parkinson's disease.

Researchers, including Dr. Pankaj Pasricha from Mayo Clinic Arizona in Scottsdale, used data from a U.S. nationwide medical record network (TriNetX) to compare more than 24,000 people who had been diagnosed with Parkinson's disease of unknown cause with those who had been diagnosed with other neurological conditions. This included more than 19,000 with Alzheimer's disease, more than 23,000 with cerebrovascular disease and more than 24,000 with none of these conditions.

The investigators matched those with Parkinson's disease with people in the other comparison groups for age, sex, race and ethnicity, and length of diagnosis.

They then compared the frequency of gut conditions included in their electronic health record for an average of six years before their Parkinson's disease diagnosis.

To test the hypothesis in a different way, the researchers divided all the adults who had been diagnosed with any of 18 gut conditions into separate groups according to their condition.

These people were then matched with people without that particular gut condition. They were monitored for five years through their medical records to see how many of them developed Parkinson's disease or other neurological disorders.

Four particular gut conditions were associated with a higher risk of a Parkinson's disease diagnosis, according to the report published online Aug. 24 in the journal Gut.

Gastroparesis (which is delayed stomach emptying), dysphagia (which is difficulty swallowing) and constipation were all associated with a more than doubled risk of Parkinson's disease in the five years before the diagnosis. Irritable bowel syndrome (IBS) without diarrhea was associated with a 17% higher risk.

“This study is the first to establish substantial observational evidence that the clinical diagnosis of not only constipation, but also dysphagia, gastroparesis and irritable bowel syndrome without diarrhea might specifically predict the development of Parkinson's disease,” the authors said in a journal news release.

The study results also suggested that appendix removal was protective, raising questions about its potential role in the disease processes leading to Parkinson's disease.

Neither inflammatory bowel disease nor removal of all or part of the vagus nerve to treat peptic ulcer were associated with a heightened risk.

People with Parkinson's disease also had greater prevalence of some other gut issues, including burning sensation or fullness of the stomach with no obvious cause, IBS with diarrhea, and diarrhea with fecal incontinence.

These conditions were also more prevalent before the onset of Alzheimer's disease or cerebrovascular disease, the study authors noted.

Study limitations include that the monitoring period was relatively short, and because it was an observational study, it cannot prove cause and effect.

“These findings warrant alertness for [gastrointestinal] syndromes in patients at higher risk for Parkinson's disease and highlight the need for further investigation of [gastrointestinal] precedents in Alzheimer's disease and cerebrovascular disease,” the authors concluded.

More information

The U.S. National Institute on Aging has more on Parkinson's disease.

SOURCE: Gut, news release, Aug. 24, 2023