The profile of gastrointestinal dysfunction in prodromal to late-stage Parkinson's disease

Abstract

Gastrointestinal dysfunction (GID) may play a key role in Parkinson's disease (PD) but its relationship with disease progression remains unclear. We recruited 404 PD cases, 37 iRBD (isolated REM Sleep Behaviour Disorder) and 105 controls. Participants completed the Gastrointestinal Dysfunction Scale for PD (GIDS-PD) and standardised disease severity assessments. Whole gut transit time (WGTT) was measured by ingestion of blue dye and recorded time to blue stools appearance ('Blue Poop Challenge') in a subset of PD cases. Gastrointestinal symptoms were more common and prevalent in iRBD and PD versus controls, and WGTT was significantly higher in PD versus controls. After adjustment for confounding factors, disease stage was not a significant predictor of GIDS-PD Constipation or Bowel Irritability scores. Longitudinal assessment of GIDS-PD scores and WGTT confirmed stability over a 4 year period. Bowel dysfunction may be a phenotypic feature in a subset of Parkinson's with implications for patient stratification and management.

Fig. 1. Mean GIDS-PD scores in controls, RBD and across H&Y stages.

Unadjusted GIDS-PD Constipation, Bowel Irritability and Upper GI domain scores increased across disease stage. GIDS-PD Gastrointestinal Dysfunction Scale for Parkinson’s disease, H&Y Hoehn and Yahr, RBD REM Sleep Behaviour disorder.

Fig. 2. Longitudinal GIDS-PD domain scores in PD and RBD patients.

No significant differences in GIDS-PD scores were observed over 4 visits spanning an average of 3-year follow-up in 245 PD participants (A–C) and over 2 year follow-up (D–F) in 25 RBD cases. GIDS-PD Gastrointestinal Dysfunction Scale–Parkinson’s disease, RBD REM Sleep Behaviour Disorder. Error bars represent SD.

Fig. 3. Whole gut transit time (in hours) in PD cases versus household controls and in PD cases stratified by H&Y stage.

WGTT was significantly higher in PD cases compared to household controls (A). Within the PD cohort, there were no differences in WGTT across H&Y stages (B). Grid line depicts cut-off for delayed transit time (59 h). H&Y Hoehn and Yahr, PD Parkinson’s Disease, WGTT whole gut transit time. ****p ≤ 0.0001. Error bars represent SD.