Tasmanian ISLAND Sleep Study: prodromal neurodegenerative disease (iRBD) is associated with subjective reports of daytime sleepiness and poor sleep quality

Abstract

AbstractBackgroundIsolated REM sleep behaviour disorder (iRBD) is a prodrome to dementia with Lewy bodies (DLB) and other neurodegenerative disease (NDD) such that over 90% of people with iRBD (pwRBD) will develop a NDD within 10 years of diagnosis. Disrupted sleep and dream‐enactment episodes are frequently observed by bed partners of pwRBD but it is unclear whether pwRBD perceive reduced sleep quality themselves, as previous studies show inconsistent results. This research aims to investigate sleep quality in iRBD and we hypothesise that people with probable iRBD (pwpRBD) will report poorer sleep quality, compared to healthy controls.MethodAdults aged 50+ years in the Tasmanian ISLAND Sleep Study, Australia, completed the single REM Sleep Behaviour Disorder Screening Question (RBD1Q) and the Pittsburgh Sleep Quality Index (PSQI) online. The PSQI includes a ‘total sleep quality’ score as well as 7 subscales: duration of sleep, sleep disturbance, sleep latency, day dysfunction due to sleepiness, sleep efficiency, overall sleep quality, and need meds to sleep.Result2,905 participants were recruited (mean (SD) age 64 (7.7) years; 26% male) and 273 (9.4%) screened positive for pRBD (45% male). In the pRBD group, 66% had poor total sleep quality, compared to 57% of controls (p = 0.001). pRBD was associated with a greater prevalence of sleep disturbance (67% vs 54%) and daytime dysfunction due to sleepiness (24% vs 11%). There was no difference in sleep duration, sleep latency, or sleep efficiency between pRBD and controls.ConclusionWe found that pwpRBD report more sleep disturbance, daytime sleepiness and overall poorer sleep quality compared to those without pRBD. This suggests that pwpRBD may suffer from greater sleepiness than has previously been reported in the literature and highlights the importance of sleep enquiries in those with suspected prodromal NDD who drive or operate machinery.