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Remote ischemic conditioning (RIC) is a procedure consisting of short cycles of ischemia applied in a limb that activates endogenous protection in distant organs, such as the brain. Despite the promising outcomes of RIC, the biochemical factors governing inter-organ communication remain largely unexplored, particularly in humans. A pilot study on 20 healthy humans was performed to identify potential circulating biochemical factors involved in RIC signalling. Blood was collected before and immediately, 4 and 22 h after the end of RIC. To characterize the responses triggered by RIC, a combination of biochemical and proteomic analysis, along with functional in vitro tests in human cells, were performed. RIC did not alter the levels of nitric oxide, bilirubin and cell-free mitochondrial DNA. In contrast, carboxyhaemoglobin levels increased following RIC at all time points and young subset, suggesting endogenous production of carbon monoxide that is a cytoprotective gasotransmitter. Additionally, the levels of glutathione and cysteinylglycine bound to proteins also increased after RIC, while glutathione catabolism decreased. Plasma proteomic analysis identified overall 828 proteins. Several steps of statistical analysis (Student's t-test, repeated measures ANOVA, with Holm corrected pairwise p-values <0.05 threshold and fold change higher or lower than 100 %) leaded to the identification of 9 proteins with altered circulating levels in response to RIC at 4h and 22h. All 9 proteins are from extracellular space or exosomes, being involved in inflammation, angiogenesis or metabolism control. In addition, RIC-conditioned plasma from young subjects protected microglial cell culture against inflammatory stimuli, indicating an anti-inflammatory effect of RIC. Nevertheless, other functional tests in neurons or endothelial cells had no effect. Overall, we present some evidence for RIC-induced anti-inflammatory and antioxidant responses in healthy human subjects, in particular in young subjects. This study is a first step towards the disclosure of signalling factors involved in RIC-mediated inter-organ communication., Competing Interests: Declaration of competing interest On the behalf of all authors, I declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To assess the predictive value of polysomnographic (PSG) data in the prospective assessment of cognitive, motor, daytime and nighttime sleep dysfunction in Parkinson's Disease (PD) patients., Methods: PD patients were assessed at baseline with video-PSG and with cognitive (MoCA), Sleep (SCOPA-Sleep Nighttime and Daytime scores) and Motor (UPDRSIII) function scales at both baseline and four years later. Linear regression analysis was used to assess the relation between PSG variables at baseline and change in symptoms scores., Results: We included a total of 25 patients, 12 with rapid eye movement (REM) sleep behavior disorder (RBD) (in 8 PSG was inconclusive, due to lack of REM sleep). MoCA scores decreased significantly at follow-up, while SCOPA-Sleep Daytime and SCOPA-Sleep Nighttime and UPDRSIII did not vary. Lower N3 percentage at baseline was significantly associated with MoCA decrease. Higher Periodic Limb Movements in Sleep index (PLMS) and the presence of RBD were significantly associated with SCOPA daytime score increase. Higher global severity of RBD, tonic RSWA and total number of motor events during REM sleep were associated with SCOPA Nighttime score increase., Conclusions: The present work suggests that PSG data could be useful for predicting PD cognitive and sleep dysfunction progression. Reduced SWS could predict deterioration of cognitive function, while baseline PLMS could be useful to predict worsening of daytime sleep dysfunction. Severity of RBD could be used for estimating nighttime sleep symptoms progression., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: Sleep dysfunction is frequent in Dementia with Lewy Bodies (DLB), but polysomnographic (PSG) data is scarce. Our objectives were to: (1) compare PSG data between DLB patients and age normative values (NV), Parkinson's Disease (PD) and idiopathic REM sleep behavior disorder (iRBD) patients; (2) evaluate the relation between of OSA, Fluctuations and Hypersomnolence and PSG data., Methods: We selected all consecutive patients with DLB, PD and iRBD that underwent video-PSG during a two year period. Clinical data was collected by file review. Video-PSG data included sleep structure, Apnea-Hypopnea Index (AHI), REM sleep atonia indexes and video file inspection of motor events (ME) during REM sleep., Results: Subjects: In this study, 19 DLB, 51 PD and 20 iRBD patients participated. Of those, nine DLB (DLB-RBD) and 23 PD (PD-RBD) patients had RBD. Compared to NV, DLB patients had significantly lower sleep efficiency, total sleep time, and REM sleep duration and higher sleep latency, wake after sleep onset and N2 duration. There were no significant relations between PSG data and OSA, hypersomnolence or fluctuations. Sleep latency and AHI were significantly higher and lower, respectively, in DLB compared to PD patients. ME frequency was higher in iRBD., Conclusion: DLB patients present significant sleep fragmentation and shortened total and REM sleep time. These changes were not related with OSA, fluctuations or hypersomnolence, suggesting a different pathophysiology. PSG data was similar in the three RBD groups, in accordance with a common neuropathological origin, except for an increase in RBD severity in patients with iRBD., (Copyright © 2018 Elsevier B.V. All rights reserved.)