Constipation is linked to accelerated cognitive and motor decline in isolated REM sleep behavior disorder

Abstract

IntroductionConstipation is associated with higher clinical severity and predicts cognitive decline in Parkinson's disease (PD). Whether the non-motor marker is associated with unfavorable motor and cognitive trajectories from the prodromal stage remains unclear. MethodsIn a longitudinal prospective cohort of subjects with isolated REM sleep behavior disorders (iRBD), subjects underwent repeated MDS-UPDRS and Mini-Mental Status Examination (MMSE) assessments. Generalized-estimating-equations (GEE) regression model was used to compare the time-dependent trajectories of MDS-UPDRS-III and MMSE scores between subjects with and without constipation at baseline. ResultsTwenty-nine subjects with constipation at baseline (iRBD+constipation) and 24 without (iRBD-constipation) were followed over 4.085 ± 2.645 years. The iRBD+constipation group presented faster decline of both MDS-UPDRS-III and MMSE scores, with additional estimated annual progression of +1.242 and −0.713 points, respectively, compared to the iRBD-constipation group (time*group p < 0.05). ConclusionConstipation in isolated RBD is associated with accelerated progression of cognitive impairment and motor symptoms.