Sleep research has been dominated by high income countries (HIC). Sleep may be different in low and middle income countries (LMIC) due to cultural, demographic, geographical and health factors. We systematically reviewed the epidemiological literature reporting sleep parameters in the adult population in LMIC and meta-analyzed the prevalence of subjective poor sleep quality and sleep duration. We identified 45 publications; over 50% of which came from China and Brazil. Of the 45 identified studies, 32 contained data on sleep quality and 17 on self-reported sleep duration. Only one study utilized polysomnography and only one study utilized actigraphy. This review provides evidence that sleep parameters in LMIC appear to be similar to those in HIC but the variability and bias found suggests any attempt to extract a universal prevalence estimate or average sleep duration from the current data is very likely flawed and should be taken with caution. In our meta-analysis we found an enormous variability that was not explicable by regional, rurality, gender, age group or sleep assessment method. Further, there was a suggestion of significant small study effect, with smaller studies reporting worse sleep. There is surprisingly little consistent high-quality data that could be used for policy, planning, or scientific purposes at a global level in low and middle-income countries about what humans spend a third of their lives doing. High-quality epidemiological research about basic sleep health parameters is needed that focuses on the whole-population in LMIC, and that uses standardized, well-validated and culturally applicable measures.
Melatonin is commonly used for sleep and jetlag at low doses. However, there is less documentation on the safety of higher doses, which are being increasingly used for a wide variety of conditions, including more recently COVID-19 prevention and treatment. The aim of this review was to investigate the safety of higher doses of melatonin in adults. Medline, Scopus, Embase and PsycINFO databases from inception until December 2019 with convenience searches until October 2020. Randomised controlled trials investigating high-dose melatonin (≥10 mg) in human adults over 30 years of age were included. Two investigators independently abstracted articles using PRISMA guidelines. Risk of bias was assessed by a committee of three investigators. 79 studies were identified with a total of 3861 participants. Studies included a large range of medical conditions. The metaanalysis was pooled data using a random effects model. The outcomes examined were the number of adverse events (AEs), serious adverse events (SAEs) and withdrawals due to AEs. A total of 29 studies (37%) made no mention of the presence or absence of AEs. Overall, only four studies met the pre-specified low risk of bias criteria for meta-analysis. In that small subset, melatonin did not cause a detectable increase in SAEs (Rate Ratio = 0.88 [0.52, 1.50], p = .64) or withdrawals due to AEs (0.93 [0.24, 3.56], p = .92), but did appear to increase the risk GTN1139625). ACM is supported by the NHMRC Centre of Research Excellence to Optimise Sleep in Brain Ageing and Neurodegeneration (CogSleep). NSM's time was funded by a salary from the University of Sydney of AEs such as drowsiness, headache and dizziness (1.40 [1.15, 1.69], p < .001).Overall, there has been limited AE reporting from high-dose melatonin studies.Based on this limited evidence, melatonin appears to have a good safety profile.Better safety reporting in future long-term trials is needed to confirm this as our confidence limits were very wide due to the paucity of suitable data.
Objective
Interest in the use of cannabidiol (CBD) is increasing worldwide as its therapeutic effects are established and legal restrictions moderated. Unlike Δ9‐tetrahydrocannabinol (Δ9‐THC), CBD does not appear to cause cognitive or psychomotor impairment. However, further assessment of its effects on cognitively demanding day‐to‐day activities, such as driving, is warranted. Here, we describe a study investigating the effects of CBD on simulated driving and cognitive performance.
Methods
Thirty healthy individuals will be recruited to participate in this randomised, double‐blind, placebo‐controlled crossover trial. Participants will complete four research sessions each involving two 30‐min simulated driving performance tests completed 45 and 210 min following oral ingestion of placebo or 15, 300, or 1,500 mg CBD. Cognitive function and subjective drug effects will be measured, and blood and oral fluid sampled, at regular intervals. Oral fluid drug testing will be performed using the Securetec DrugWipe® 5S and Dräger DrugTest® 5000 devices to determine whether CBD increases the risk of “false‐positive” roadside tests to Δ9‐THC. Noninferiority analyses will test the hypothesis that CBD is no more impairing than placebo.
Conclusion
This study will clarify the risks involved in driving following CBD use and assist in ensuring the safe use of CBD by drivers.
It is often claimed that we are living through a global sleep loss epidemic where, as a society, we increasingly get less and less sleep. However, our previously published systematic review of all relevant studies until May 2011 failed to find strong evidence that this had happened worldwide. In this current review, we updated that search and found 5 new articles with data from 12 countries starting in the 1960s-1980s and culminating in 2001-2012. We still find little evidence for the claimed epidemic as different countries have increasing, decreasing or stable sleep. There remain strong concerns about methodological quality in many of the studies and the effect of the rise of smart phones and tablets cannot yet be assessed. We also found data in 5 reports about 4 countries where markers of sleep quality do seem to have declined.
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