Constipation Predicts Cognitive Decline in Parkinson's Disease: Results from the COPPADIS Cohort at 2-Year Follow-up and Comparison with a Control Group

Background: Constipation has been linked to cognitive impairment development in Parkinson's disease (PD). Objective: Our aim was to analyze cognitive changes observed in PD patients and controls from a Spanish cohort with regards to the presence or not of constipation. Methods: PD patients and controls recruited from 35 centers of Spain from the COPPADIS cohort from January 2016 to November 2017 were followed-up during 2 years. The change in cognitive status from baseline (V0) to 2-year follow-up was assessed with the PD-CRS (Parkinson's Disease Cognitive Rating Scale). Subjects with a score >= 1 on item 21 of the NMSS (Non-Motor Symptoms Scale) at baseline (V0) were considered as "with constipation". Regression analyses were applied for determining the contribution of constipation in cognitive changes. Results: At V0, 39.7% (198/499) of PD patients presented constipation compared to 11.4% of controls (14/123) (p < 0.0001). No change was observed in cognitive status (PD-CRS total score) neither in controls without constipation (from 100.24 +/- 13.72 to 100.27 +/- 13.68; p = 0.971) and with constipation (from 94.71 +/- 10.96 to 93.93 +/- 13.03; p = 0.615). The PD-CRS total score decreased significantly in PD patients with constipation (from 89.14 +/- 15.36 to 85.97 +/- 18.09; p <0.0001; Coehn's effect = -0.35) compared to patients without constipation (from 93.92 +/- 15.58 to 93.14 +/- 17.52; p = 0.250) (p = 0.018). In PD patients, to suffer from constipation at VO was associated with a decrease in the PD-CRS total score from V0 to V2 (beta=-0.1; 95%CI, -4.36 - -0.27; p = 0.026) and having cognitive impairment at V2 (OR =1.79; 95%CI, 1.01 - 3.17; p = 0.045). Conclusion: Constipation is associated with cognitive decline in PD patients but not in controls.