The glymphatic system is postulated to be a mechanism of brain Aβ-amyloid clearance and to be most effective during sleep. Ablation of the astrocytic end-feet expressed water-channel protein, Aquaporin-4, in mice, results in impairment of this clearance mechanism and increased brain Aβ-amyloid deposition, suggesting that Aquaporin-4 plays a pivotal role in glymphatic function. Currently there is a paucity of literature regarding the impact of AQP4 genetic variation on sleep, brain Aβ-amyloid burden and their relationship to each other in humans. To address this a cross-sectional observational study was undertaken in cognitively normal older adults from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Genetic variants in AQP4 were investigated with respect to self-reported Pittsburgh Sleep Quality Index sleep parameters, positron emission tomography derived brain Aβ-amyloid burden and whether these genetic variants moderated the sleep-Aβ-amyloid burden relationship. One AQP4 variant, rs72878776, was associated with poorer overall sleep quality, while several SNPs moderated the effect of sleep latency (rs491148, rs9951307, rs7135406, rs3875089, rs151246) and duration (rs72878776, rs491148 and rs2339214) on brain Aβ-amyloid burden. This study suggests that AQP4 genetic variation moderates the relationship between sleep and brain Aβ-amyloid burden, which adds weight to the proposed glymphatic system being a potential Aβ-amyloid clearance mechanism and suggests that AQP4 genetic variation may impair this function. Further, AQP4 genetic variation should be considered when interpreting sleep-Aβ relationships.

Ten-year-old children appear capable, and by extension adults too, of applying the SR. Future research is now required to establish if education about the SR will translate into sun protection behaviour change.

ObjectiveParamedics are at the forefront of emergency healthcare. Quick and careful decision making is required to effectively care for their patients; however, excessive sleepiness has the potential to impact on clinical decision making. Studies investigating the effects of night shift work on sleepiness, cognitive function and clinical performance in the prehospital setting are limited. Here, we aimed to determine the extent to which sleepiness is experienced over the course of a simulation-based 13-hour night shift and how this impacts on clinical performance and reaction time.MethodsTwenty-four second year paramedic students undertook a 13-hour night shift simulation study in August 2017. The study consisted of 10 real-to-life clinical scenarios. Sleepiness, perceived workload and motivation were self-reported, and clinical performance graded for each scenario. Reaction time, visual attention and task switching were also evaluated following each block of two scenarios.ResultsThe accuracy of participants’ clinical decision making declined significantly over the 13-hour night shift simulation. This was accompanied by an increase in sleepiness and a steady decline in motivation. Participants performed significantly better on the cognitive flexibility task across the duration of the simulated night shift and no changes were observed on the reaction time task. Perceived workload varied across the course of the night.ConclusionOverall, increased sleepiness and decreased clinical decision making were noted towards the end of the 13-hour simulated night shift. It is unclear the extent to which these results are reflective of practising paramedics who have endured several years of night shift work, however, this could have serious implications for patient outcomes and warrants further investigation.

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