Abstract
Background: Parkinson's disease (PD) is an age-related neurodegenerative condition with a range of motor and non-motor symptoms. Early non-motor symptoms include constipation and orthostatic hypotension, while dysphagia is common in established PD. Previous work by our group showed that many people lose weight within a year of diagnosis. This study explored if fluid intake was also reduced in people with newly diagnosed PD. Materials and methods: We invited people with newly diagnosed PD (within six months of a diagnosis or longer if not requiring treatment) to join the study. Controls were household members of the participants with Parkinson's disease. Participants undertook a number of assessments, including a 24-hour dietary recall, a video-recorded swallowing assessment, and grading of stool sample consistency using the Bristol Stool Chart. Results: We recruited 30 participants, 19 with newly diagnosed PD and 11 household controls. People living with PD reported significantly lower fluid intake from drinks (control median = 1799 mL, PD median = 1124 mL, p=0.005 for difference in medians). The difference was not compensated for by fluid intake from elsewhere in the diet. People with PD drank fluid slightly slower than the controls, 6.0 mL/second vs 7.5 mL/second, but this did not reach statistical significance. Participants with PD had significantly harder stools than controls, with a mean Bristol Stool Chart number of 3.2 vs 4.6 for controls (p=0.01). Conclusion: Newly diagnosed PD is associated with significantly reduced intake of fluids from beverages, which may contribute to constipation and orthostatic hypotension