Melatonin has become a popular dietary supplement, most known as a chronobiotic, and for establishing healthy sleep. Research over the last decade into cancer, Alzheimer’s disease, multiple sclerosis, fertility, PCOS, and many other conditions, combined with the COVID-19 pandemic, has led to greater awareness of melatonin because of its ability to act as a potent antioxidant, immune-active agent, and mitochondrial regulator. There are distinct similarities between melatonin and vitamin D in the depth and breadth of their impact on health. Both act as hormones, affect multiple systems through their immune-modulating, anti-inflammatory functions, are found in the skin, and are responsive to sunlight and darkness. In fact, there may be similarities between the widespread concern about vitamin D deficiency as a “sunlight deficiency” and reduced melatonin secretion as a result of “darkness deficiency” from overexposure to artificial blue light. The trend toward greater use of melatonin supplements has resulted in concern about its safety, especially higher doses, long-term use, and application in certain populations (e.g., children). This review aims to evaluate the recent data on melatonin’s mechanisms, its clinical uses beyond sleep, safety concerns, and a thorough summary of therapeutic considerations concerning dietary supplementation, including the different formats available (animal, synthetic, and phytomelatonin), dosing, timing, contraindications, and nutrient combinations.

https://www.mdpi.com/2072-6643/14/19/3934/pdf?version=1664433564

Is Melatonin the “Next Vitamin D”?: A Review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements

Over the last few years, novel and important aspects of nutrition that are often overlooked in nutritional epidemiology, experimental research, and recommendations for health maintenance and disease prevention concerning the circadian rhythmicity of feeding, as well as the bidirectional interaction of nutrition with central and peripheral endogenous circadian clocks, and with other rhythmic behaviors including the sleep-wake cycle have received increasing attention from the research community [...].

/pdf/nutrition-sleep-circadian-rhythms-and-health-implications-3bdvx17v.pdf

Nutrition, Sleep, Circadian Rhythms, and Health Implications: “Come Together”

OBJECTIVE
The present systematic review aims to assess the impact of the COVID19 pandemic on the sleep quality of students.


METHODS
An electronic search was performed in the databases and in gray literature for articles published up to January 2022. The results included observational studies that assessed sleep quality through validated questionnaires, comparing moments pre and postCOVID19 pandemic. The risk of bias was assessed using the Joanna Briggs Institute Critical Assessment Checklist. The Grading of Assessment, Development and Evaluation (GRADE) was used to assess the certainty of scientific evidence. Estimates of interest were calculated using random effects meta-analyses and possible confounding factors were meta-regressed.


RESULTS
Eighteen studies were considered for qualitative synthesis and thirteen were considered for meta-analysis. Considering the comparison of means obtained by the Pittsburgh Sleep Quality Index, there was an increase in the scores obtained during the pandemic period [MD = -0.39; 95% CI = -0.72 - -0.07; I2 = 88.31%], thus evidencing a slight worsening in the sleep quality of these individuals. Risk of bias was considered low in nine studies, moderate in eight studies, and high in one study. The unemployment rate (%) in the country of origin of each included study partially explained the heterogeneity of analysis. GRADE analysis showed a very low certainty of scientific evidence.


CONCLUSION
The COVID-19 pandemic may have a slight negative impact on the sleep quality of high school and college students, but the evidence is still uncertain. The socioeconomic reality must be considered when evaluating this outcome.

Impact of the COVID-19 pandemic on the sleep quality of students: A meta-analysis and meta-regression.

STUDY OBJECTIVES
To investigate the association of 24-hour urinary potassium excretion with subjective sleep quality in the general population.


METHODS
In this cross-sectional study, a population of patients aged 18 years or older was randomly selected from Xinjiang, China in 2019, 24-hour urine samples collected, and Pittsburgh Sleep Quality Index (PSQI) questionnaires assessed. Participants were divided into two groups (upper and lower median of 24-hour urinary potassium excretion [24.8 μmol/L]). Poor sleep quality was defined as PSQI global score ≥ 6. Associations between 24-hour urinary potassium excretion and sleep quality were assessed by multiple logistic regression analysis in total participants and those stratified by sex.


RESULTS
In total, 24-hour urine samples were collected from 1,147 participants, of whom data for those with complete urine samples and PSQI data were analyzed (N = 727; mean age = 48.7 years; percentage of women = 62%). Compared with the upper median group for 24-hour urinary potassium excretion, the lower median group showed a significantly higher PSQI global score (6 vs 5, P=0.011), and prevalence of poor sleep quality (51.7% vs 42.2%, P=0.011). In a fully-adjusted model of multivariate logistic regression, the lower median group showed 1.50-fold increased odds for presence of poor sleep quality (95% confidence interval:1.01-2.24, P=0.045). Sex-specific analyses translated these results to women, but not to men.


CONCLUSIONS
These results suggest that low potassium intake, indicated by lower potassium excretion, is associated with poor sleep quality in the general population, especially among women. Therefore, additional research is necessary to clarify the effect of increasing potassium intake to improve sleep quality.

24-hour urinary potassium excretion is negatively associated with subjective sleep quality in the general population, independent of sleep-disordered breathing.

/pdf/examining-physical-wellness-as-the-fundamental-element-for-1vne5g8m.pdf

Examining Physical Wellness as the Fundamental Element for Achieving Holistic Well-Being in Older Persons: Review of Literature and Practical Application in Daily Life

Sleep is a cyclically occurring, transient, and functional state that is controlled primarily by neurobiological processes. Sleep disorders and insomnia are increasingly being diagnosed at all ages. These are risk factors for depression, mental disorders, coronary heart disease, metabolic syndrome, and/or high blood pressure. A number of factors can negatively affect sleep quality, including the use of stimulants, stress, anxiety, and the use of electronic devices before sleep. A growing body of evidence suggests that nutrition, physical activity, and sleep hygiene can significantly affect the quality of sleep. The aim of this review was to discuss the factors that can affect sleep quality, such as nutrition, stimulants, and physical activity.

/pdf/sleep-quality-a-narrative-review-on-nutrition-stimulants-and-2blt36d8.pdf

Monika Sejbuk

Papers

Sleep Quality: A Narrative Review on Nutrition, Stimulants, and Physical Activity as Important Factors