Melatonin Is a Feasible, Safe, and Acceptable Intervention in Doctors and Nurses Working Nightshifts: The MIDNIGHT Trial

Significance of Melatonin in the Regulation of Circadian Rhythms and Disease Management

Melatonin, the 'hormone of darkness' is a neuronal hormone secreted by the pineal gland and other extra pineal sites. Responsible for the circadian rhythm and seasonal behaviour of vertebrates and mammals, melatonin is responsible for regulating various physiological conditions and the maintenance of sleep, body weight and the neuronal activities of the ocular sites. With its unique amphiphilic structure, melatonin can cross the cellular barriers and elucidate its activities in the subcellular components, including mitochondria. Melatonin is a potential scavenger of oxygen and nitrogen-reactive species and can directly obliterate the ROS and RNS by a receptor-independent mechanism. It can also regulate the pro- and anti-inflammatory cytokines in various pathological conditions and exhibit therapeutic activities against neurodegenerative, psychiatric disorders and cancer. Melatonin is also found to show its effects on major organs, particularly the brain, liver and heart, and also imparts a role in the modulation of the immune system. Thus, melatonin is a multifaceted candidate with immense therapeutic potential and is still considered an effective supplement on various therapies. This is primarily due to rectification of aberrant circadian rhythm by improvement of sleep quality associated with risk development of neurodegenerative, cognitive, cardiovascular and other metabolic disorders, thereby enhancing the quality of life.

Melatonin treatment has consistent but transient beneficial effects on sleep measures and pain in patients with severe chronic pain: the DREAM-CP randomised controlled trial

BACKGROUND

Sleep disturbance is a major issue for patients with chronic pain. Melatonin has been shown to improve symptoms of fibromyalgia, but its efficacy in other chronic non-malignant pain conditions is not fully known. Hence, we determined the effect of melatonin in patients with severe noncancer chronic pain.

METHODS

This was a randomised double-blinded crossover trial of modified-release melatonin as Circadin™ compared with placebo. Sixty male and female subjects with chronic severe pain were randomised to receive either 2 mg of Circadin™ or placebo before sleep for 6 weeks, followed by a >4 week washout, then crossing over to the other treatment. Sleep disturbance, quality, and latency were measured using three different validated sleep assessment tools. The primary outcome measure was self-reported sleep disturbance after 6 weeks of treatment. Adverse events were also recorded.

RESULTS

Sleep disturbance after 6 weeks was not significantly altered by melatonin treatment, but differences between melatonin and placebo treatment periods after 3 weeks were seen: sleep disturbance (P=0.014), latency (P=0.04), overall sleep quality (P=0.004), and effect of pain on sleep (P=0.032). Pain intensity scores improved during both treatment periods (both P<0.001). There were no differences in adverse events between treatment periods.

CONCLUSIONS

Circadin™ treatment did not improve sleep disturbance in patients with severe chronic pain compared with placebo at 6 weeks, but there were consistent improvements in aspects of sleep in the shorter term. Given its favourable safety profile, it could be beneficial for some patients with chronic pain.

CLINICAL TRIAL REGISTRATION

ISRCTN12861060.

The use of prolonged-release melatonin in circadian medicine: a systematic review

INTRODUCTION

Melatonin, a hormone produced by the pineal gland, regulates the sleep-wake cycle and is effective in restoring biological rhythms. Prolonged-release melatonin (PRM) is designed to mimic the natural physiological pattern of melatonin release. In circadian medicine, PRM can be used to treat sleep and circadian rhythm disorders, as well as numerous organic diseases associated with sleep disorders.

EVIDENCE ACQUISITION

This systematic review analyzed 62 studies and adhered to the PRISMA guidelines, examining the effectiveness of PRM in organic pathologies and mental disorders.

EVIDENCE SYNTHESIS

The main evidence concerns primary insomnia in subjects over the age of 55, showing significant improvements in sleep quality. In neurodevelopmental disorders, there is evidence of a positive impact on sleep quality and quality of life for patients and their caregivers. PRM shows efficacy in the treatment of sleep disorders in mood disorders, schizophrenia, and neurocognitive disorders, but requires further confirmation. The additional use of PRM is supported for the withdrawal of chronic benzodiazepine therapies. The tolerability and safety of PRM are excellent, with ample evidence supporting the absence of tolerance and dependence.

CONCLUSIONS

Overall, PRM in circadian medicine is an effective chronopharmaceutical for restoring the sleep-wake rhythm in patients with insomnia disorder. This efficacy may also extend to sleep disorders associated with mood, neurodevelopmental and neurocognitive disorders, suggesting a further potential role in insomnia associated with various organic diseases.

Supraneural versus Infraneural Approach to transforaMinal Epidural StEroid injection for unilateral lumbosacral radicular pain (SIAMESE): a study protocol for a randomised non-inferiority trial

Background

Lumbosacral radicular pain is commonly treated by transforaminal steroid epidural injection. There are two methods: the supraneural and the infraneural approaches. The supraneural approach can result in rare but catastrophic consequences from injury to the radiculomedullary artery. The infraneural technique avoids the artery; both approaches show efficacy and are used locally.

Methods

This is a protocol for a randomised, single-blinded, non-inferiority trial of infraneural vs supraneural transforaminal epidural injection for lumbosacral radicular pain at a tertiary referral pain management clinic. Adult patients (n=92) with moderate-to-severe lumbosacral radicular pain of >3 months duration, scheduled for transforaminal epidural steroid injection, will be randomised to epidural by either the infraneural or supraneural approach. Only the treating physicians will know which route is used. The primary outcome measure is the differential impact on pain intensity score at 3 months. Secondary outcome measures will include disability and function scores, sleep and activity measures, and adverse events. Participants will be followed up for 12 months.

Conclusions

This study will determine whether the techniques are comparable and, if so, will enable recommendations for the use of an approach without risk of artery damage and catastrophic injury.

Clinical trial registration

ISRCTN 36195887.

Resting and Recharging: A Narrative Review of Strategies to Improve Sleep During Residency Training

BACKGROUND

Residency involves demanding training with long hours that may cause fatigue and sleep deprivation and adversely impact residents and patients under their care.

OBJECTIVE

To identify, using a narrative review, evidence-based interventions to reduce the physiologic effects of fatigue and sleep deprivation from overnight and night shift work.

METHODS

A PubMed literature search was conducted through August 30, 2021, using the terms "resident" and "sleep" in the title or abstract and further narrowed using a third search term. Observational studies, randomized controlled trials, systematic reviews, and meta-analyses of human subjects written and published in English were included. Studies that were not specific to residents or medical interns or did not investigate an intervention were excluded. Additional studies were identified by bibliography review. Due to the heterogeneity of study design and intervention, a narrative review approach was chosen with results categorized into non-pharmacological and pharmacological interventions.

RESULTS

Initially, 271 articles were identified, which were narrowed to 28 articles with the use of a third search term related to sleep. Bibliography review yielded 4 additional articles. Data on interventions are limited by the heterogeneity of medical specialty, sample size, length of follow-up, and reliance on self-report. Non-pharmacological interventions including strategic scheduling and sleep hygiene may improve sleep and well-being. The available evidence, including randomized controlled trials, to support pharmacological interventions is limited.

CONCLUSIONS

Non-pharmacological approaches to mitigating fatigue and sleep deprivation have varying effectiveness to improve sleep for residents; however, data for pharmacological interventions is limited.

Efficacy of Dietary Supplements on Sleep Quality and Daytime Function of Shift Workers: A Systematic Review and Meta-Analysis

Background

Dietary supplements (DSs) may be useful for managing shift work disorder. But the efficiency of outcomes in clinical trials using simulated shift work populations as subjects is controversial. This review explores the potential role of DSs for improving sleep quality, daily functioning, and mood among shift workers in the real world.

Methods

A related literature search was conducted in PubMed, Web of Science, Embase, and Cochrane Library databases from their inception to July 2021. Information was collected on “shift work,” “irregular working hours,” “night shift,” “dietary supplements,” and “nutraceutical research data.” Sleep quality-related scales were the primary outcome measures. The meta-analysis was conducted using RevMan 5.4 (Cochrane Collaboration, London, England) and Stata 15.0 (StataCorp, LLC, College Station, TX, USA). Heterogeneity was examined by using I2 statistics, and publication bias was assessed via Egger's regression test.

Results

Twelve studies, which involved 917 participants, met the inclusion criteria. The DS groups had significant improvement in sleep quality scores (8 randomized controlled trials [RCTs]: p = 0.04; standard mean difference (SMD), −0.45 [−0.88 to −0.03]) and daytime function (7 RCTs: p = 0.02; SMD, −0.50 [−0.92 to −0.08]). The DS groups did not have a significant improvement in psychomotor vigilance (4 RCTs: p = 0.25; SMD, 0.52 [−0.36 to 1.41]), depression (5 RCTs: p = 0.14; SMD, −0.19 [−0.45 to 0.06]), or anxiety (4 RCTs: p = 0.27; SMD, −0.23 [−0.65 to 0.18]). All RCTs suggested a positive safety profile for DSs.

Conclusions

The findings of this meta-analysis indicated DSs may be beneficial for improving sleep quality and daytime function in shift workers. Although there is a wide range of DSs, the small amount of literature included for each type does not allow for subgroup analysis to be used to eliminate high heterogeneity. We have not yet included literatures on other languages either. Given these limitations of the study, there is still a need for more well-designed randomized controlled trials so that our review can be updated in the future to make the results more conclusive.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=273558, PROSPERO: CRD42021273558.

"LONG COVID"-A hypothesis for understanding the biological basis and pharmacological treatment strategy

Infection of humans with SARS‐CoV‐2 virus causes a disease known colloquially as “COVID‐19” with symptoms ranging from asymptomatic to severe pneumonia. Initial pathology is due to the virus binding to the ACE‐2 protein on endothelial cells lining blood vessels and entering these cells in order to replicate. Viral replication causes oxidative stress due to elevated levels of reactive oxygen species. Many (~60%) of the infected people appear to have eliminated the virus from their body after 28 days and resume normal activity. However, a significant proportion (~40%) experience a variety of symptoms (loss of smell and/or taste, fatigue, cough, aching pain, “brain fog,” insomnia, shortness of breath, and tachycardia) after 12 weeks and are diagnosed with a syndrome named “LONG COVID.” Longitudinal clinical studies in a group of subjects who were infected with SARS‐CoV‐2 have been compared to a non‐infected matched group of subjects. A cohort of infected subjects can be identified by a battery of cytokine markers to have persistent, low level grade of inflammation and often self‐report two or more troubling symptoms. There is no drug that will relieve their symptoms effectively. It is hypothesized that drugs that activate the intracellular transcription factor, nuclear factor erythroid‐derived 2‐like 2 (NRF2) may increase the expression of enzymes to synthesize the intracellular antioxidant, glutathione that will quench free radicals causing oxidative stress. The hormone melatonin has been identified as an activator of NRF2 and a relatively safe chemical for most people to ingest chronically. Thus, it is an option for consideration of re‐purposing studies in “LONG COVID” subjects experiencing insomnia, depression, fatigue, and “brain fog” but not tachycardia. Appropriately designed clinical trials are required to evaluate melatonin.

Objective Assessment of Sleep Patterns among Night-Shift Workers: A Scoping Review

In this scoping review of the literature, we identified the types and the parameters of objective measurements to assess sleep patterns among night-shift workers. We conducted a literature search using electronic databases for studies published from 1991 to 2020 and charted and summarized key information. We included 32 studies in the review. Polysomnography was used in 6 studies and wearable sleep detection devices were utilized in 26 studies. The duration of sleep assessment using the wearable devices ranged from 1 day to ≥4 weeks, and more than half of the studies collected data for >2 weeks. The majority of the studies used subjective questionnaires, such as the Karolinska Sleepiness Scale, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, in addition to objective sleep measurements. Total sleep time was the most common parameter, followed by sleep efficiency, sleep onset latency, and time or frequency of being awake. As the utilization of wearable devices to assess the sleep patterns of night-shift workers is expected to increase, further evaluation of device accuracy and precision, optimal data collection period, and key parameters is warranted.

Extent of sleep problems and relationship with severity of chronic pain using three validated sleep assessment tools

Objective

Chronic pain can impact on sleep, but the extent and nature of sleep problems in patients with chronic pain are incompletely clear. Several validated tools are available for sleep assessment but they each capture different aspects. We aimed to describe the extent of sleep issues in patients with chronic non-malignant pain using three different validated sleep assessment tools and to determine the relationship of sleep issues with pain severity recorded using the Brief Pain Inventory (BPI), a commonly used self-assessment tool in pain clinics. The BPI has a single question on the interference of pain on sleep and we also compared this with the validated sleep tools.

Design

Prospective, cross-sectional study.

Setting

Pain management clinic at a large teaching hospital in the United Kingdom.

Subjects

Adult patients (with chronic non-malignant pain of at least 3 months’ duration) attending clinic during a 2-month period.

Methods

Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Pain and Sleep Questionnaire-3 (PSQ-3) and the Verran Snyder-Halpern (VSH) sleep scale, plus the BPI. Duration and type of pain, current medications and demographic data were recorded.

Results

We recruited 51 patients and 82% had poor sleep quality as shown by PSQIscores above five. PSQI (p = 0.0002), PSQ-3 (p = 0.0032), VSH sleep efficiency (p = 0.012), sleep disturbance (p = 0.0014) and waking after sleep onset (p = 0.0005) scores were associated with worse BPI pain scores. BPI sleep interference scores concurred broadly with the validated sleep tools. Median [range] sleep duration was 5.5 [3.0–10.0] hours and was also related to pain score (p = 0.0032).

Conclusion

Chronic pain has a marked impact on sleep regardless of the assessment tool used. The sleep interference question in the BPI could be used routinely for initial identification of sleep problems in patients with chronic pain.

Maternal Serum Melatonin Increases During Pregnancy and Falls Immediately After Delivery Implicating the Placenta as a Major Source of Melatonin

Melatonin is a neuroendocrine hormone which regulates circadian rhythm and is also an antioxidant. The role of melatonin in pregnancy is emerging. The enzymes needed for endogenous synthesis of melatonin have been identified in the placenta, although the contribution to circulating maternal melatonin in normal pregnancy is unclear. This work aimed to determine serum levels of melatonin and its major metabolite 6-hydroxymelatonin sulfate (6-OHMS) in normal pregnant women during each trimester of pregnancy, and immediately after delivery. Blood samples were obtained from a cohort of healthy pregnant women during each trimester of pregnancy (n = 26), from women scheduled for elective Cesarean section (CS) before and after delivery (n = 15), along with placental samples, and from healthy non-pregnant women as controls (n = 30). Melatonin and its major metabolite, 6-OHMS, were measured using enzyme immunoassay. Levels of serum melatonin were significantly higher during pregnancy than in non-pregnant women (P = 0.025) and increased throughout pregnancy (P < 0.0001). In women undergoing CS, serum melatonin decreased markedly 24 h after delivery (P = 0.0013). Similar results were seen for serum levels of 6-OHMS, and placental tissue 6-OHMS levels correlated with week of gestation at delivery (p = 0.018). In summary, maternal melatonin production is higher in pregnant than in non-pregnant women, increases significantly during pregnancy with highest levels in the third trimester, and decreases abruptly after delivery. These results suggest that the placenta is a major source of melatonin and supports a physiological role for melatonin in pregnancy.