The prevalence of gastrointestinal dysfunction and its impact on quality of life in Parkinson's disease.

Gastrointestinal (GI) dysfunction is one of the most common and earliest non-motor symptoms (NMS) in Parkinson's disease (PD). We aimed to study the prevalence and severity of GI dysfunction and its impact on quality of life (QoL) in patients with PD. This was a single-centre, questionnaire-based cross-sectional study enrolling 150 PD patients meeting the UKPDS Brain Bank criteria with a minimum disease duration of 5 years. An equal number of age-matched healthy controls (HC) were included. A detailed clinical and neurological evaluation was followed by five GI, other NMS and QoL scales. The mean age of PD patients was 53.69 ± 11.79 years, and 51.83 ± 10.91 years in HC (p = 0.16). Women comprised 37.3% of PD patients and 46.7% of HC (p < 0.001). The most common GI dysfunction in PD patients was constipation, followed by bloating and drooling. Compared to HC, PD patients had a significantly higher prevalence of drooling, dysphagia, sweet food preference, bloating, heartburn and constipation (p < 0.001). PD patients also had significantly higher severity of heartburn and constipation (p < 0.001). Duration of constipation correlated with other NMS and autonomic dysfunction (p < 0.003). Malnutrition in PD patients was associated with higher cognitive impairment. The GI dysfunction led to worse QoL in PD patients than in HCs (p < 0.001). GI dysfunction in PD patients is associated with higher NMS and worse QoL, which is an important area for intervention.