By Melanie Hinze
Danish researchers have found a significant association between irritable bowel disease (IBD) and later Parkinson’s disease (PD).
Their nationwide, population-based, cohort study, published in Gut, included all 76,477 individuals diagnosed with IBD in Denmark between 1977 and 2014, along with more than 7.5 million gender-, age- and vital-status-matched individuals without IBD from the general population.
Participants were followed from IBD diagnosis/index date to the occurrence of PD or multiple system atrophy (MSA), as recorded in the Danish National Patient Register.
During the more than 83 million years’ follow up, PD was diagnosed in 335 patients with IBD (0.4%) and 39,784 patients without (0.5%), whereas MSA was diagnosed in 13 patients with IBD (0.02%) and 866 patients without (0.01%).
Analysis of the results showed that patients with IBD were 22% more likely to develop PD. This increased risk was present regardless of sex, age group or length of follow up.
Risk of parkinsonism was increased by 35% among patients with ulcerative colitis but not significantly in those with Crohn’s disease.
The study authors said the findings suggested that clinicians should be aware of parkinsonism symptoms in patients with IBD and called for further investigations on the role of intestinal inflammation and brain-gut-microbiome axis in the aetiology of parkinsonism.
Dr Andrew Evans, Director of the Movement Disorders Service at Royal Melbourne Hospital, said ‘there is a growing awareness of the connection between the intestinal environment and the nervous system’.
‘Lewy pathology in the gut has now been demonstrated up to 20 years before the emergence of motor symptoms; while alpha-synuclein, the major component of this pathology, has an important role in the innate immune defence system of the enteric nervous system.’
While noting that the use of medical care biased associations between PD and other medical conditions, Dr Evans told Medicine Today that ‘this epidemiological study used well-curated national databases to provide further clinical evidence for a potential link between the health of the gut microbiota and brain health.’
Gut 2018; 0: 1-7; doi:10.1136/gutjnl-2017-315666.