Irritable bowel syndrome implicated in Parkinson’s disease

Patients with irritable bowel syndrome (IBS) may be at heightened risk of developing future Parkinson’s disease (PD), as suggested in a study.

The analysis used data from the Swedish population and included 56,564 PD patients and matched controls (30 individuals per case).

In the PD cohort, mean age at index date was 75.1 years. Compared with controls, patients were more likely to have comorbidities but less likely to be born outside of Sweden, have lower educational attainment, and have chronic obstructive pulmonary disease (COPD).

A total of 5,457 individuals developed IBS over the entire observational period, among whom 253 were in the PD group and 5,204 in the matched control group (0.4 percent vs 0.3 percent).

On multivariable conditional regression analysis, IBS conveyed a 44-percent higher risk of PD (odds ratio, 1.44, 95 percent confidence interval [CI], 1.27–1.63). In the temporal relationship models, PD risk was elevated by 53 percent and 38 percent ≥5 years and ≥10 years after IBS diagnosis, respectively. This relationship was pronounced among IBS patients diagnosed at age ≥50 years, although the test for interaction was not statistically significant (p=0.11). 

On further analysis using data from the Swedish Twin Registry, which involved 3,046 IBS patients with self-reported abdominal symptoms and 41,179 non-IBS controls, IBS posed no increased hazard of PD (hazard ratio, 1.25, 95 percent CI, 0.87–1.81).

The present data provide additional evidence supporting the importance of the gut–brain axis in PD.