Background. Many patients with end stage renal disease (ESRD) undergoing dialysis therapy suffer from sleep disturbances. The aim of this study was to investigate the prevalence of sleep disorders in a large population of uraemic patients recruited from 20 different dialytic centres in Triveneto. Methods. 883 patients on maintenance dialysis were enrolled in the study. Demographic, lifestyle, renal and dialysis data were recorded. Renal parameters were compared with the database of the Veneto Dialysis Register. Using a self-administered questionnaire we assessed the presence of the following sleep disorders: insomnia, restless leg syndrome (RLS), obstructive sleep apnoea syndrome (OSAS), excessive daytime sleepiness (EDS), possible narcolepsy, sleepwalking, nightmares and possible rapid eye movement behaviour disorders (RBD). Moreover, in order to determine the prevalence of sleep disturbances and the possible effect of demographic or clinical data on sleep, we divided our population into two groups: with (SLEEP+) and without (SLEEP−) sleep disorders. Results. The questionnaire revealed the presence of insomnia (69.1%), RLS (18.4%), OSAS (23.6%), EDS (11.8%), possible narcolepsy (1.4%), sleepwalking (2.1%), nightmares (13.3%) and possible RBD (2.3%). Eighty percent demonstrated SLEEP+, having at least one sleep disorder. Independent risk factors for sleep disorders were advanced age (P<0.001), excessive alcohol intake (P<0.04), cigarette smoking (P<0.006), polyneuropathy (P<0.05) and dialysis shift in the morning (P<0.001). Conclusions. The questionnaire showed a high presence of sleep disruption in dialytic populations. Awareness by Italian nephrologists regarding sleep disruption seems to be insufficient. Our data might help nephrologists to deal with uraemic patients with possible sleep disorders. Concerning the high prevalence of possible narcolepsy, further studies using polysomnographic records are necessary to confirm our results.

Objective To study the role of GBA variants in the risk for isolated REM sleep behavior disorder (iRBD) and conversion to overt neurodegeneration. Methods A total of 4,147 individuals were included: 1,061 patients with iRBD and 3,086 controls. GBA was fully sequenced using molecular inversion probes and Sanger sequencing. We analyzed the effects of GBA variants on the risk of iRBD, age at onset (AAO), and conversion rates. Results GBA variants were found in 9.5% of patients with iRBD compared to 4.1% of controls (odds ratio, 2.45; 95% confidence interval [CI], 1.87–3.22; p = 1 × 10⁻¹⁰). The estimated OR for mild p.N370S variant carriers was 3.69 (95% CI, 1.90–7.14; p = 3.5 × 10⁻⁵), while for severe variant carriers it was 17.55 (95% CI, 2.11–145.9; p = 0.0015). Carriers of severe GBA variants had an average AAO of 52.8 years, 7–8 years earlier than those with mild variants or noncarriers (p = 0.029). Of the GBA variant carriers with available data, 52.5% had converted, compared to 35.6% of noncarriers (p = 0.011), with a trend for faster conversion among severe GBA variant carriers. However, the results on AAO and conversion were based on small numbers and should be interpreted with caution. Conclusions GBA variants robustly and differentially increase the risk of iRBD. The rate of conversion to neurodegeneration is also increased and may be faster among severe GBA variant carriers, although confirmation will be required in larger samples. Screening for RBD in healthy carriers of GBA variants should be studied as a potential way to identify GBA variant carriers who will develop a synucleinopathy in the future.