Circadian disruption and human health: A bidirectional relationship

Melatonin Prevents Non-image-Forming Visual System Alterations Induced by Experimental Glaucoma in Rats

Glaucoma is a blindness-causing disease that involves selective damage to retinal ganglion cells (RGCs) and their axons. A subset of RGCs expressing the photopigment melanopsin regulates non-image-forming visual system functions, such as pupillary light reflex and circadian rhythms. We analyzed the effect of melatonin on the non-image-forming visual system alterations induced by experimental glaucoma. For this purpose, male Wistar rats were weekly injected with vehicle or chondroitin sulfate into the eye anterior chamber. The non-image-forming visual system was analyzed in terms of (1) melanopsin-expressing RGC number, (2) anterograde transport from the retina to the olivary pretectal nucleus and the suprachiasmatic nuclei, (3) blue- and white light-induced pupillary light reflex, (4) light-induced c-Fos expression in the suprachiasmatic nuclei, (5) daily rhythm of locomotor activity, and (6) mitochondria in melanopsin-expressing RGC cells. Melatonin prevented the effect of experimental glaucoma on melanopsin-expressing RGC number, blue- and white light-induced pupil constriction, retina-olivary pretectal nucleus, and retina- suprachiasmatic nuclei communication, light-induced c-Fos expression in the suprachiasmatic nuclei, and alterations in the locomotor activity daily rhythm. In addition, melatonin prevented the effect of glaucoma on melanopsin-expressing RGC mitochondrial alterations. These results support that melatonin protected the non-image-forming visual system against glaucoma, probably through a mitochondrial protective mechanism.

Melatonin in Wine and Beer: Beneficial Effects

Melatonin is a hormone secreted in the pineal gland with several functions, especially regulation of circadian sleep cycle and the biological processes related to it. This review evaluates the bioavailability of melatonin and resulting metabolites, the presence of melatonin in wine and beer and factors that influence it, and finally the different benefits related to treatment with melatonin. When administered orally, melatonin is mainly absorbed in the rectum and the ileum; it has a half-life of about 0.45–1 h and is extensively inactivated in the liver by phase 2 enzymes. Melatonin (MEL) concentration varies from picograms to ng/mL in fermented beverages such as wine and beer, depending on the fermentation process. These low quantities, within a dietary intake, are enough to reach significant plasma concentrations of melatonin, and are thus able to exert beneficial effects. Melatonin has demonstrated antioxidant, anticarcinogenic, immunomodulatory and neuroprotective actions. These benefits are related to its free radical scavenging properties as well and the direct interaction with melatonin receptors, which are involved in complex intracellular signaling pathways, including inhibition of angiogenesis and cell proliferation, among others. In the present review, the current evidence on the effects of melatonin on different pathophysiological conditions is also discussed.

Reductive stability evaluation of 6-azopurine photoswitches for the regulation of CKIα activity and circadian rhythms

6-Azopurines were evaluated for their reductive stability, and the ability to modulate CKIα activity and cellular circadian rhythms, revealing key challenges for long-term activity modulation utilizing chronophotopharmacology.

Minimally Invasive Ways of Determining Circadian Rhythms in Humans

Circadian rhythm exerts a critical role in mammalian health and disease. A malfunctioning circadian clock can be a consequence, as well as the cause of several pathophysiologies. Clinical therapies and research may also be influenced by the clock. Since the most suitable manner of revealing this rhythm in humans is not yet established, we discuss existing methods and seek to determine the most feasible ones.

Multicenter Study on Sleep and Circadian Alterations as Objective Markers of Mild Cognitive Impairment and Alzheimer’s Disease Reveals Sex Differences

Background: Circadian and sleep disturbances are associated with increased risk of mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Wearable activity trackers could provide a new approach in diagnosis and prevention. Objective: To evaluate sleep and circadian rhythm parameters, through wearable activity trackers, in MCI and AD patients as compared to controls, focusing on sex dissimilarities. Methods: Based on minute level data from consumer wearable devices, we analyzed actigraphic sleep parameters by applying an electromedical type I registered algorithm, and the corresponding circadian variables in 158 subjects: 86 females and 72 males (42 AD, 28 MCI, and 88 controls). Moreover, we used a confusion-matrix chart method to assess accuracy, precision, sensitivity, and specificity of two decision-tree models based on actigraphic data in predicting disease or health status. Results: Wake after sleep onset (WASO) was higher (p < 0.001) and sleep efficiency (SE) lower (p = 0.003) in MCI, and Sleep Regularity Index (SRI) was lower in AD patients compared to controls (p = 0.004). SE was lower in male AD compared to female AD (p = 0.038) and SRI lower in male AD compared to male controls (p = 0.008), male MCI (p = 0.047), but also female AD subjects (p = 0.046). Mesor was significantly lower in males in the overall population. Age reduced the dissimilarities for WASO and SE but demonstrated sex differences for amplitude (p = 0.009) in the overall population, controls (p = 0.005), and AD subjects (p = 0.034). The confusion-matrices showed good predictive power of actigraphic data. Conclusion: Actigraphic data could help identify disease or health status. Sex (possibly gender) differences could impact on neurodegeneration and disease trajectory with potential clinical applications.

Melatonin, an ubiquitous metabolic regulator: functions, mechanisms and effects on circadian disruption and degenerative diseases

The last four decades, we assist to an increasing scientific interest on melatonin, a circadian hormone, a metabolic regulator which influences not only plants' metabolism and their defense against pathogens but mostly the animals and humans' metabolic pathways, their response to circadian disruption, stress and burnout syndrome. In humans, as a hormonal regulator, produced in the pineal grand as well in mitochondria, melatonin is involved in different, complex intracellular signaling pathways, with antioxidant and immune stimulating effects, proving to act as a circadian synchronizer, as a preventive and therapeutic agent in many degenerative diseases, and especially in hormone-dependent cancers. Preclinical or clinical studies showed recently the mechanisms involved in regulating the cellular activity, its role in aging and circadian disturbances and impact on degenerative diseases. Melatonin proved to have an anti-inflammatory, antiapoptotic and powerful antioxidant effect by subtle mechanisms in mitochondrial metabolic pathways. This overview includes recent and relevant literature data related to the impact of endogenous and exogeneous melatonin on the prevention of cancer progression and treatment of various degenerative diseases. Metabolomics, an emerging new omics' technology, based on high performance liquid chromatography coupled with mass spectrometry is presented as an encouraging technique to fingerprint and realize a precise evaluation and monitoring of the turnover of melatonin and its metabolites in different pathological circumstances.

Chronobiotic effect of melatonin in experimental optic neuritis

Optic neuritis (ON) is an inflammatory condition of the optic nerve, which leads to retinal ganglion cell (RGC) loss. A subset of RGCs expressing the photopigment melanopsin regulates non-image-forming visual system (NIFVS) functions such as pupillary light reflex (PLR) and circadian rhythms. Melatonin is a chronobiotic agent able to regulate the circadian system. We analyzed the effect of ON on the NIFVS, and the effect of melatonin on the NIFVS alterations induced by ON. For this purpose, optic nerves from male Wistar rats received vehicle or bacterial lipopolysaccharide (LPS), and one group of animals received a subcutaneous pellet of melatonin or a sham procedure. The NIFVS was analyzed in terms of: i) blue light-evoked PLR, ii) the communication between the retina and the suprachiasmatic nuclei (by anterograde transport, and ex vivo magnetic resonance images), iii) locomotor activity rhythm, and iv) Brn3a(+) and melanopsin(+) RGC number (by immunohistochemistry). Experimental ON significantly decreased the blue light-evoked PLR, induced a misconnection between the retina and the suprachiasmatic nuclei, decreased Brn3a(+) RGCs, but not melanopsin(+) RGC number. A bilateral injection of LPS significantly increased the light (but not dark) phase locomotor activity, rhythm periodicity, and time of offset activity. Melatonin prevented the decrease in blue light-evoked PLR, and locomotor activity rhythm alterations induced by ON. These results support that ON provoked alterations of the circadian physiology, and that melatonin could restore the circadian system misalignment.

Molecular link between circadian clocks and cardiac function: a network of core clock, slave clock, and effectors

The circadian rhythm has a strong influence on both cardiac physiology and disease in humans. Preclinical studies primarily using tissue-specific transgenic mouse models have contributed to our understanding of the molecular mechanism of the circadian clock in the cardiovascular system. The core clock driven by CLOCK:BMAL1 complex functions as a universal timing machinery that primarily sets the pace in all mammalian cell types. In one specific cell or tissue type, core clock may control a secondary transcriptional oscillator, conceptualized as slave clock, which confers the oscillatory expression of tissue-specific effectors. Here, we discuss a core clock-slave clock-effectors network, which links the molecular clock to cardiac function.

The effect of circadian preferences on insomnia severity and depressive symptoms via sleep hygiene in older adults with depression and healthy controls

BACKGROUND

The elderly population is increasing globally. Thus, researches focus on the causes and treatment of insomnia, a noteworthy ageing problem. This study aims to investigate the relationship between chronotype and insomnia and whether sleep hygiene mediates this relationship in older adults with depression (OAD).

METHODS

We assessed subjective insomnia severity, sleep hygiene, chronotype, depressive symptoms, and anxiety symptoms of 82 OAD and 70 healthy controls using the Sleep Hygiene Index (SHI), Insomnia Severity Index (ISI), Morningness-Eveningness Questionnaire (MEQ), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI).

RESULTS

The mediation effect of SHI and ISI scores were evaluated in the relationship between MEQ and BDI total scores in OAD. The results showed that MEQ performed its effect on BDI through ISI with full mediation (effect = -0.16, SE: 0.07, 95% CI: -0.3230 to -0.0336). The mediation effect of SHI and BDI scores were evaluated in the relationship between MEQ and ISI total scores in OAD. In this model, it was found that MEQ significantly performed its effect on ISI through SHI and BDI. BDI and SHI predicted the ISI variable as partial mediators (respectively, effect = -0.05, SE: 0.03, 95% CI: -0.1073 to -0.0100; effect = -0.06, SE: 0.02, 95% CI: -0.1051 to -0.0129).

CONCLUSIONS

Sleep hygiene practices could be essential for the natural functioning of the biological clock and the interrelation of depression and insomnia. Longitudinal follow-up studies of structured sleep hygiene approaches are needed in terms of cost-effectiveness, in OAD.

Effects of Cone Connexin-36 Disruption on Light Adaptation and Circadian Regulation of the Photopic ERG

Purpose

The present study tested the hypothesis that connexin-36 (Cx36) and gap junctions between photoreceptor cells contribute to the circadian rhythm of the photopic electroretinogram (ERG) b-wave amplitude.

Methods

Cone-specific disruption of Cx36 was obtained in mice with a floxed Gjd2 gene and human red/green pigment promoter (HRGP)-driven Cre recombinase. Standard ERG, spectral-domain optical coherence tomography (SD-OCT) and histochemical methods were used.

Results

HRGPcreGjd2fl/fl mice had a selective reduction in Cx36 protein in the outer plexiform layer; no reduction in Cx36 was observed in the inner plexiform layer. Cx36 disruption had no effect on the number of cones, the thickness of the photoreceptor layer, or the scotopic ERG responses. However, there was a reduction of the photopic ERG circadian rhythm, with b-wave amplitudes in the day and the night locked in the daytime, light-adapted state. In HRGPcreGjd2+/+and Gjd2fl/fl controls, the circadian rhythm of light-adapted ERG persisted, similar to that in wild type mice.

Conclusions

Cx36 regulation contributes to the circadian rhythm of light-adapted ERG; in the absence of photoreceptor gap junctions, mice appear to be in a fully light-adapted state regardless of the time of day. The higher amplitudes and reduced circadian regulation of the b-wave of HRGPcreGjd2fl/fl mice may be due to increased synaptic strength at the cone to ON bipolar cell synapse due to electrotonic isolation of the terminals lacking gap junctions.

Circadian and Sleep Metabolomics Across Species

Under normal circadian function, metabolic control is temporally coordinated across tissues and behaviors with a 24-h period. However, circadian disruption results in negative consequences for metabolic homeostasis including energy or redox imbalances. Yet, circadian disruption has become increasingly prevalent within today's society due to many factors including sleep loss. Metabolic consequences of both have been revealed by metabolomics analyses of circadian biology and sleep. Specifically, two primary analytical platforms, mass spectrometry and nuclear magnetic resonance spectroscopy, have been used to study molecular clock and sleep influences on overall metabolic rhythmicity. For example, human studies have demonstrated the prevalence of metabolic rhythms in human biology, as well as pan-metabolome consequences of sleep disruption. However, human studies are limited to peripheral metabolic readouts primarily through minimally invasive procedures. For further tissue- and organism-specific investigations, a number of model systems have been studied, based upon the conserved nature of both the molecular clock and sleep across species. Here we summarize human studies as well as key findings from metabolomics studies using mice, Drosophila, and zebrafish. While informative, a limitation in existing literature is a lack of interpretation regarding dynamic synthesis or catabolism within metabolite pools. To this extent, future work incorporating isotope tracers, specific metabolite reporters, and single-cell metabolomics may provide a means of exploring dynamic activity in pathways of interest.

Some Near- and Far-Environmental Effects on Human Health and Disease with a Focus on the Cardiovascular System

Environmental effects on human physiopathology are revisited herein from a chronobiologic viewpoint, with a focus on the cardiovascular system. Physiological variables undergo recurring changes that are predictable in a statistical, albeit not deterministic way. Biological rhythms cover a broad range of frequencies, which are usually shared by the environment as “co-periodisms”. Some of these photic and non-photic periodicities shared by the environment and physiopathology are reviewed herein, together with their possible underlying mechanisms. A plausible cascade of events from the long-period cycles found in the cosmic environment to those affecting the Earth’s atmosphere and weather conditions is presented, which may shed light on how they may shape the cycles characterizing human health. Maps of important cycles shared between the environment and physiopathology are being catalogued in an atlas of chronomes with the goal of distinguishing between strong and weak associations and providing an estimate of the lag that can be anticipated before observing physiological changes.

The Role of Daylight for Humans: Gaps in Current Knowledge

Daylight stems solely from direct, scattered and reflected sunlight, and undergoes dynamic changes in irradiance and spectral power composition due to latitude, time of day, time of year and the nature of the physical environment (reflections, buildings and vegetation). Humans and their ancestors evolved under these natural day/night cycles over millions of years. Electric light, a relatively recent invention, interacts and competes with the natural light-dark cycle to impact human biology. What are the consequences of living in industrialised urban areas with much less daylight and more use of electric light, throughout the day (and at night), on general health and quality of life? In this workshop report, we have classified key gaps of knowledge in daylight research into three main groups: (I) uncertainty as to daylight quantity and quality needed for "optimal" physiological and psychological functioning, (II) lack of consensus on practical measurement and assessment methods and tools for monitoring real (day) light exposure across multiple time scales, and (III) insufficient integration and exchange of daylight knowledge bases from different disciplines. Crucial short and long-term objectives to fill these gaps are proposed.

Activity Tracker-Based Metrics as Digital Markers of Cardiometabolic Health in Working Adults: Cross-Sectional Study

Background

Greater adoption of wearable devices with multiple sensors may enhance personalized health monitoring, facilitate early detection of some diseases, and further scale up population health screening. However, few studies have explored the utility of data from wearable fitness trackers in cardiovascular and metabolic disease risk prediction.

Objective

This study aimed to investigate the associations between a range of activity metrics derived from a wearable consumer-grade fitness tracker and major modifiable biomarkers of cardiometabolic disease in a working-age population.

Methods

This was a cross-sectional study of 83 working adults. Participants wore Fitbit Charge 2 for 21 consecutive days and went through a health assessment, including fasting blood tests. The following clinical biomarkers were collected: BMI, waist circumference, waist-to-hip ratio, blood pressure, triglycerides (TGs), high-density lipoprotein (HDL) and low-density lipoprotein cholesterol, and blood glucose. We used a range of wearable-derived metrics based on steps, heart rate (HR), and energy expenditure, including measures of stability of circadian activity rhythms, sedentary time, and time spent at various intensities of physical activity. Spearman rank correlation was used for preliminary analysis. Multiple linear regression adjusted for potential confounders was used to determine the extent to which each metric of activity was associated with continuous clinical biomarkers. In addition, pairwise multiple regression was used to investigate the significance and mutual dependence of activity metrics when two or more of them had significant association with the same outcome from the previous step of the analysis.

Results

The participants were predominantly middle aged (mean age 44.3 years, SD 12), Chinese (62/83, 75%), and male (64/83, 77%). Blood biomarkers of cardiometabolic disease (HDL cholesterol and TGs) were significantly associated with steps-based activity metrics independent of age, gender, ethnicity, education, and shift work, whereas body composition biomarkers (BMI, waist circumference, and waist-to-hip ratio) were significantly associated with energy expenditure–based and HR-based metrics when adjusted for the same confounders. Steps-based interdaily stability of circadian activity rhythm was strongly associated with HDL (beta=5.4 per 10% change; 95% CI 1.8 to 9.0; P=.005) and TG (beta=−27.7 per 10% change; 95% CI −48.4 to −7.0; P=.01). Average daily steps were negatively associated with TG (beta=−6.8 per 1000 steps; 95% CI −13.0 to −0.6; P=.04). The difference between average HR and resting HR was significantly associated with BMI (beta=−.5; 95% CI −1.0 to −0.1; P=.01) and waist circumference (beta=−1.3; 95% CI −2.4 to −0.2; P=.03).

Conclusions

Wearable consumer-grade fitness trackers can provide acceptably accurate and meaningful information, which might be used in the risk prediction of cardiometabolic disease. Our results showed the beneficial effects of stable daily patterns of locomotor activity for cardiometabolic health. Study findings should be further replicated with larger population studies.

Effect of Morning Light Glasses and Night Short-Wavelength Filter Glasses on Sleep-Wake Rhythmicity in Medical Inpatients

Sleep and circadian rhythm disorders are common amongst medical inpatients. They are caused by a mixture of factors, including noise, loss of habitual daily routines, and abnormal exposure to light, which tends to be insufficient in the day and too high at night. The aim of the present study was to test the efficacy of morning light therapy plus night short-wavelength filter glasses on sleep quality/timing, and sleepiness/mood over the daytime hours, in a group of well-characterized medical inpatients. Thirty-three inpatients were enrolled and randomized (2:1) to either treatment (n = 22; 13 males, 48.3 ± 13.3 years) or standard of care (n = 11; 8 males, 56.9 ± 12.9 years). On admission, all underwent a baseline assessment of sleep quality/timing and diurnal preference. During hospitalization they underwent monitoring of sleep quality/timing (sleep diaries and actigraphy), plus hourly assessment of sleepiness/mood during the daytime hours on one, standard day of hospitalization. Patients in the treatment arm were administered bright light through glasses immediately after awakening, and wore short-wavelength filter glasses in the evening hours. Treated and untreated patients were comparable in terms of demographics, disease severity/comorbidity, diurnal preference and pre-admission sleep quality/timing. During hospitalization, sleep diaries documented a trend for a lower number of night awakenings in treated compared to untreated patients (1.6 ± 0.8 vs. 2.4 ± 1.3, p = 0.057). Actigraphy documented significantly earlier day mode in treated compared to untreated patients (06:39 ± 00:35 vs. 07:44 ± 00:40, p = 0.008). Sleepiness during a standard day of hospitalization, recorded between 09:30 and 21:30, showed physiological variation in treated compared to untreated patients, who exhibited a more blunted profile. The level of sleepiness reported by treated patients was lower over the 09:30-14:30 interval, i.e., soon after light administration (interaction effect: F = 2.661; p = 0.026). Mood levels were generally higher in treated patients, with statistically significant differences over the 09:30-14:30 time interval, i.e., soon after light administration (treatment: F = 5.692, p = 0.026). In conclusion, treatment with morning bright light and short-wavelength filter glasses in the evening, which was well tolerated, showed positive results in terms of sleepiness/mood over the morning hours and a trend for decreased night awakenings.

A Multifactorial Approach to Sleep and Its Association with Health-Related Quality of Life in a Multiethnic Asian Working Population: A Cross-Sectional Analysis

This study aims to explore if objectively and subjectively measured sleep parameters are associated with physical and mental health-related quality of life in a multiethnic working population in Singapore. We performed a cross-sectional analysis with data from 329 full-time employees enrolled in a workplace cohort study in Singapore. The Short-Form 36v2 (SF-36v2) survey was used to assess health-related quality of life, in terms of physical and mental health. Subjective and objective sleep parameters were measured using the Pittsburgh Sleep Quality Index and wrist actigraphy, respectively. Generalized linear modeling was performed to examine the association between sleep parameters and health-related quality of life. After adjusting for confounders, subjectively measured sleep disturbances were associated with a lower physical health-related quality of life, whereas higher, objectively measured sleep efficiency was associated with greater physical health-related quality of life. Subjectively measured daytime dysfunction was associated with impaired mental health-related quality of life. Using both objective and subjective measurements of sleep, the current study suggests that there is an association between sleep and health-related quality of life. Workplace health-promotion planners in Singapore should consider programmes that educate workers on better sleep hygiene practices in an effort to improve sleep and health-related quality of life.

Light-Stress Influences the Composition of the Murine Gut Microbiome, Memory Function, and Plasma Metabolome

The gut microbiome plays an important role in the mammalian host and when in proper balance helps protect health and prevent disease. Host environmental stress and its influence on the gut microbiome, health, and disease is an emerging area of research. Exposures to unnatural light cycles are becoming increasingly common due to travel and shift work. However, much remains unknown about how these changes influence the microbiome and host health. This information is needed to understand and predict the relationship between the microbiome and host response to altered sleep cycles. In the present study, we exposed three cohorts of mice to different light cycle regimens for 12 consecutive weeks; including continuous light, continuous dark, and a standard light dark regimen consisting of 12 h light followed by 12 h of dark. After exposure, motor and memory behavior, and the composition of the fecal microbiome and plasma metabolome were measured. Memory potential was significantly reduced in mice exposed to continuous light, whereas rotarod performance was minimally affected. The overall composition of the microbiome was relatively constant over time. However, Bacteroidales Rikenellaceae was relatively more abundant in mice exposed to continuous dark, while Bacteroidales S24-7 was relatively more abundant in mice exposed to continuous light. The plasma metabolome after the continuous dark exposure differed from the other exposure conditions. Several plasma metabolites, including glycolic acid, tryptophan, pyruvate, and several unidentified metabolites, were correlated to continuous dark and light exposure conditions. Networking analyses showed that serotonin was positively correlated with three microbial families (Rikenellaceae, Ruminococcaceae, and Turicibacteraceae), while tryptophan was negatively correlated with abundance of Bacteroidales S24-7 based on light exposure. This study provides the foundation for future studies into the mechanisms underlying the role of the gut microbiome on the murine host during light-dark stress.

Assessment of Circadian Rhythms

Circadian rhythms are observed in most physiologic functions across a variety of species and are controlled by a master pacemaker in the brain called the suprachiasmatic nucleus. The complex nature of the circadian system and the impact of circadian disruption on sleep, health, and well-being support the need to assess internal circadian timing in the clinical setting. The ability to assess circadian rhythms and the degree of circadian disruption can help in categorizing subtypes or even new circadian rhythm disorders and aid in the clinical management of the these disorders.

Smith-Magenis Syndrome: Molecular Basis of a Genetic-Driven Melatonin Circadian Secretion Disorder

Smith-Magenis syndrome (SMS), linked to Retinoic Acid Induced (RAI1) haploinsufficiency, is a unique model of the inversion of circadian melatonin secretion. In this regard, this model is a formidable approach to better understand circadian melatonin secretion cycle disorders and the role of the RAI1 gene in this cycle. Sleep-wake cycle disorders in SMS include sleep maintenance disorders with a phase advance and intense sleepiness around noon. These disorders have been linked to a general disturbance of sleep-wake rhythm and coexist with inverted secretion of melatonin. The exact mechanism underlying the inversion of circadian melatonin secretion in SMS has rarely been discussed. We suggest three hypotheses that could account for the inversion of circadian melatonin secretion and discuss them. First, inversion of the circadian melatonin secretion rhythm could be linked to alterations in light signal transduction. Second, this inversion could imply global misalignment of the circadian system. Third, the inversion is not linked to a global circadian clock shift but rather to a specific impairment in the melatonin secretion pathway between the suprachiasmatic nuclei (SCN) and pinealocytes. The development of diurnal SMS animal models that produce melatonin appears to be an indispensable step to further understand the molecular basis of the circadian melatonin secretion rhythm.

Ways of knowing in precision health

Precision health can provide an avenue to bridge and integrate ways of knowing for research and practice. Nurse scientists have a long-standing interest in using multiple sources of information to address research questions of significance to the profession and discipline of nursing, which can lead to much needed contributions to precision health care. In this paper, nursing scientists discuss emerging research methods including omics, electronic sensors, and geospatial data, and mixed methods that further develop nursing science and contribute to precision health initiatives. The authors provide exemplars of the types of knowledge and ways of knowing that, using these and other advanced data and analytic strategies, may advance precision health within the context of nursing science.

SleepOMICS: How Big Data Can Revolutionize Sleep Science

Sleep disorders have reached epidemic proportions worldwide, affecting the youth as well as the elderly, crossing the entire lifespan in both developed and developing countries. "Real-life" behavioral (sensor-based), molecular, digital, and epidemiological big data represent a source of an impressive wealth of information that can be exploited in order to advance the field of sleep research. It can be anticipated that big data will have a profound impact, potentially enabling the dissection of differences and oscillations in sleep dynamics and architecture at the individual level ("sleepOMICS"), thus paving the way for a targeted, "one-size-does-not-fit-all" management of sleep disorders ("precision sleep medicine").