A case report of pancreatic exocrine insufficiency in a patient with Parkinson's disease: A coincidence or is there more to it than meets the eye?

Pancreatic exocrine insufficiency (PEI) is an under-diagnosed condition. Untreated PEI can result in developing gastrointestinal symptoms and long-term complications including weight loss, nutrient deficiencies, sarcopenia and osteoporosis. Current best practice recommends testing for PEI in certain disorders including chronic pancreatitis, cystic fibrosis, pancreatic cancer and post-pancreatic surgery. However, there is increasing evidence that PEI is associated with a number of conditions in addition to the aforementioned diseases. These 'at-risk' conditions are a heterogeneous group of diseases, for example, diabetes mellitus, people living with human immunodeficiency virus, high alcohol intake, and coeliac disease. The pathophysiology of some of 'at-risk' conditions is becoming increasingly recognised; therefore, the list of associated conditions are in evolving process. We present a case of a 60-year-old male with Parkinson's disease and persistent abdominal pain who was found to have low faecal elastase levels indicative of severe PEI. His past medical history included none of the known risk factors for PEI. After examining the literature, we report a similar pathophysiological process underlying the development of pancreatitis and Parkinson's disease which is dysfunction of the Unfolded Protein Response. We suggest further research to assess the prevalence of PEI in the population of patients with Parkinson's disease.