Empirical clustering to identify individuals for whom insomnia is more closely related to suicidal ideation.

BACKGROUND: Although the effect sizes are modest, insomnia is consistently associated with suicidal thoughts and behaviors. Subgroup analyses can efficiently identify for whom insomnia is most relevant to suicidal ideation. To improve clinical case identification, the present study sought to identify subclusters of lifetime suicidal ideators for whom insomnia was most closely related to current suicidal ideation. METHODS: Data on N = 4750 lifetime suicidal ideators were extracted from the Military Suicide Research Consortium's Common Data Elements. Data on sociodemographic characteristics, severity and history of suicidal thoughts and behaviors, and related clinical characteristics were clustered by unsupervised machine learning algorithms. Robust Poisson regression estimated cluster by insomnia associations with current suicidal ideation. RESULTS: Three clusters were identified: a modest symptom severity cluster (N = 1757, 37.0 %), an elevated severity cluster (N = 1444 30.4 %), and a high severity cluster (N = 1549 32.6 %). In Cluster 1, insomnia was associated with current suicidal ideation (PRR 1.29 [1.13-1.46]) and remained significant after adjusting for sociodemographic and clinical covariates. In Cluster 2, insomnia was associated with current suicidal ideation (PRR 1.14 [1.01-1.30]), but not after adjusting for sociodemographic and clinical covariates. In Cluster 3, insomnia was associated with current suicidal ideation (PRR 1.12 [1.03-1.21]) and remained significant after adjusting for sociodemographic covariates, but not clinical covariates. LIMITATIONS: Cross-sectional design, lack of diagnostic data, non-representative sample. CONCLUSION: Insomnia appears more closely related to current suicidal ideation among modest severity individuals than other subgroups. Future work should use prospective designs and more comprehensive risk factor measures to confirm these findings.

Risk for Suicide and Homicide Peaks at Night: Findings From the National Violent Death Reporting System, 35 States, 2003-2017.

Objective: The Mind after Midnight hypothesis proposes that nocturnal wakefulness increases the risk for dysregulated behaviors. Prior studies highlight a greater risk for suicide at night after adjusting for population wakefulness. How this risk varies hour to hour, differs across subgroups, or applies to other behaviors is unknown.Methods: Data on 78,647 suicides and 50,526 homicides from the National Violent Death Reporting System were combined with population wakefulness data for 2003-2017 from the American Time Use Survey. Hourly incident risk ratios (IRRs) were estimated after adjusting for population wakefulness. Two-way analysis of variances identified significant time-by-subgroup interactions that were quantified in post hoc analyses.Results: Suicide counts peaked at 12:00 PM, while homicide counts peaked at 10:00- 11:00 PM. Adjusting for demographics and population wakefulness revealed a 5-fold greater risk for suicide at 3:00 AM (aIRR: 5.20 [4.74-5.70]) and an 8-fold greater risk for homicide at 2:00 AM (aIRR: 8.04 [6.35-10.2]). Hourly risk for suicide varied by age, ethnicity, blood alcohol level, and current partner conflict. Hourly risk for homicide varied by sex and blood alcohol level.Conclusions: Risk for suicide and homicide is greater at night than expected based on the number of people awake at that time. Nighttime risk was greater among young adults and those intoxicated with alcohol, but not among those with a history of suicidal ideation or attempts. Further research should evaluate mechanisms of risk and confirm these findings at an individual level.

Nitrous oxide emissions from soybean in response to drained and undrained soils and previous corn nitrogen management.

While corn (Zea mays L.)-soybean (Glycine max. Merr. L) is a predominant rotation system in the US Midwest the residual effect of nitrogen (N) fertilization to corn on the following year's soybean and N2O emissions under different soil drainage conditions has not been studied. Our objective was to quantify agronomic parameters and season-long N2O emissions from soybean as affected by N management (0-N and optimum N rate of 135 kg N ha-1 as single or split application) during the previous corn crop under drained and undrained systems. Urea was applied to corn, and residual N effects were measured on soybean the following year in a poorly drained soil with and without subsurface tile drainage. Drainage reduced N2O emissions in one of three growing seasons but had no effect on soybean yield or N removal in grain. Nitrogen management in the previous corn crop had no effect on soybean grain yield, N removal, or N2O emissions during the soybean phase. Even though soybean symbiotically fixes N and removes more N in grain than corn, N2O emissions were more than two times greater during the corn phase (mean = 1.83 kg N ha-1) due to N fertilization than during the soybean phase (mean = 0.80 kg N ha-1). Also, N2O emissions in the corn years were increased possibly due to decomposition of the previous year's soybean crop residue compared to corn residue decomposition in the soybean years. Tile drainage, especially where wet soil conditions are prevalent, is a viable option to mitigate agricultural N2O emissions.

Left atrial appendage occlusion in patients suffering from advanced chronic kidney disease (stage 4 and 5). Long-term follow-up.

INTRODUCTION AND OBJECTIVES: Advanced chronic kidney disease (A-CKD) combined with atrial fibrillation increases the risk of both thrombogenic and bleeding events. Left atrial appendage occlusion (LAAO) may be an alternative to oral anticoagulation to prevent thromboembolic events. We aimed to evaluate the outcomes of LAAO in patients with A-CKD. METHODS: Comparison at long-term follow-up of patients diagnosed with and without A-CKD (eGFR<30 mL/min/1.73 m2 ) who underwent LAAO between 2009 and May 2022. RESULTS: Five hundred seventy-three patients were included. Eighty-one (14%) were diagnosed with A-CKD. There were no differences in sex, age, and cardiovascular risk factors, except for diabetes which was more frequent in patients with A-CKD. The control group had higher rates of stroke, both ischemic and hemorrhagic. There were no differences in the CHA2 DS2 -VASc score, although A-CKD patients had a higher bleeding risk according to the HASBLED scale. Global procedural success was 99.1%. At follow-up, there were no differences in stroke rate: at 1-year (HR: 1.22, IC-95%: 0.14-10.42, p = 0.861); at 5-years (HR: 0.60, IC-95%: 0.08-4.58, p = 0.594). Although bleeding events were higher in the A-CKD group, no differences were found in major bleeding (defined BARC ≥ 3) at 1-year (HR: 1.34, IC-95%: 0.63-2.88, p = 0.464) or at 5-years follow-up (HR: 1.30, IC-95%: 0.69-2.48, p = 0.434). Mortality rate at 5 years was higher in the A-CKD patients (HR: 1.84, IC-95%: 1.18-2.87, p = 0.012). CONCLUSIONS: LAAO is an effective and safe treatment in A-CKD patients to prevent ischemic events and bleeding. This strategy could be an alternative to oral anticoagulation in this high-risk group of patients.

Effectiveness and Safety of an Outpatient Program for Percutaneous Left Atrial Appendage Occlusion.

BACKGROUND: Left atrial appendage occlusion (LAAO) is a safe and effective alternative to oral anticoagulation for thromboprophylaxis in patients with nonvalvular atrial fibrillation. Technological development in devices and imaging techniques, as well as accumulated experience, have increased procedural success rates and decreased complications. Same-day discharge protocols have been proposed in the field of structural heart disease, but this approach has not been studied in detail for the LAAO procedure. AIM: The aim of this study is to assess the safety and efficacy of an outpatient program for LAAO when compared to the conventional treatment approach. METHODS: We present a retrospective, non-randomized single-center study of 262 consecutive patients undergoing LAAO. Patients were divided into two groups, the first (n = 131) followed a conventional protocol (CP), and the second (n = 131) an outpatient protocol (OP). The primary composite endpoint comprised MACCE (death, stroke, and bleeding), cardiac tamponade, vascular complication, or attendance in the emergency department after hospital discharge at 30 days. RESULTS: The overall success rate was 99.6%, with a periprocedural complication rate of 2.29%. With regards to the CP versus OP group, there were no differences between incidences of the primary composite endpoint (6.1% PC vs. 3.0% PA, p = 0.24), or after an analysis, with propensity score matching. No differences were observed in the individual endpoints. There was a decrease in hospital length of stay in the same-day discharge group (p < 0.01). CONCLUSIONS: A same-day discharge LAAO program is safe, effective, and feasible when compared to the conventional strategy. Moreover, it reduces hospital length of stay, which might have clinical and economic benefits.

Left Atrial Appendage Occlusion Under Miniaturized Transesophageal Echocardiographic Guidance and Conscious Sedation: Multicenter European Experience.

BACKGROUND: Left atrial appendage occlusion (LAAO) procedures are widely guided by standard transesophageal echocardiography (TEE) probes, requiring general anesthesia in most patients. The use of miniaturized TEE probes allows for LAAO guidance under local anesthesia and offers an attractive imaging alternative to standard TEE probes. OBJECTIVES: The aim of this study was to assess the safety and efficacy of miniaturized TEE probes for procedural guidance of LAAO. METHODS: Multicenter retrospective observational study of LAAO procedures performed under miniaturized TEE guidance and conscious sedation. The primary efficacy endpoint was technical success. The secondary efficacy endpoint was procedural success (technical success without major periprocedural complications). The safety outcome was a composite of major periprocedural complications. RESULTS: A total of 546 consecutive LAAO procedures were performed in 5 European centers. Technical success was achieved in 534 (98.0%) patients. Sixteen major periprocedural complications occurred in 15 (2.9%) patients, yielding a procedural success rate of 97.0%. Conversion to general anesthesia was required in 4 (0.7%) patients. Short-term imaging follow-up was available in 422 patients with an incidence of major (>5 mm) TEE-detected residual leaks of 0.7%, complete LAA occlusion of 82.2% on cardiac computed tomography, and device-related thrombus of 5%. As compared with procedural 2-dimensional imaging for device sizing, preprocedural assessment by 3-dimensional imaging resulted in improved technical success (100% vs 95.0%; P < 0.001). CONCLUSIONS: LAAO under conscious sedation and miniaturized TEE guidance is safe and feasible with a high rate of technical success and a low rate of periprocedural complications.

Overexpression screen of chromosome 21 genes reveals modulators of Sonic hedgehog signaling relevant to Down syndrome.

Trisomy 21 and mutations in the Sonic hedgehog (SHH) signaling pathway cause overlapping and pleiotropic phenotypes including cerebellar hypoplasia, craniofacial abnormalities, congenital heart defects and Hirschsprung disease. Trisomic cells derived from individuals with Down syndrome possess deficits in SHH signaling, suggesting that overexpression of human chromosome 21 genes may contribute to SHH-associated phenotypes by disrupting normal SHH signaling during development. However, chromosome 21 does not encode any known components of the canonical SHH pathway. Here, we sought to identify chromosome 21 genes that modulate SHH signaling by overexpressing 163 chromosome 21 cDNAs in a series of SHH-responsive mouse cell lines. We confirmed overexpression of trisomic candidate genes using RNA sequencing in the cerebella of Ts65Dn and TcMAC21 mice, model systems for Down syndrome. Our findings indicate that some human chromosome 21 genes, including DYRK1A, upregulate SHH signaling, whereas others, such as HMGN1, inhibit SHH signaling. Individual overexpression of four genes (B3GALT5, ETS2, HMGN1 and MIS18A) inhibits the SHH-dependent proliferation of primary granule cell precursors. Our study prioritizes dosage-sensitive chromosome 21 genes for future mechanistic studies. Identification of the genes that modulate SHH signaling may suggest new therapeutic avenues for ameliorating Down syndrome phenotypes.

Animal models of human insomnia.

Insomnia disorder (chronic sleep continuity disturbance) is a debilitating condition affecting 5%-10% of the adult population worldwide. To date, researchers have attempted to model insomnia in animals through breeding strategies that create pathologically short-sleeping individuals or with drugs and environmental contexts that directly impose sleeplessness. While these approaches have been invaluable for identifying insomnia susceptibility genes and mapping the neural networks that underpin sleep-wake regulation, they fail to capture concurrently several of the core clinical diagnostic features of insomnia disorder in humans, where sleep continuity disturbance is self-perpetuating, occurs despite adequate sleep opportunity, and is often not accompanied by significant changes in sleep duration or architecture. In the present review, we discuss these issues and then outline ways animal models can be used to develop approaches that are more ecologically valid in their recapitulation of chronic insomnia's natural aetiology and pathophysiology. Conditioning of self-generated sleep loss with these methods promises to create a better understanding of the neuroadaptations that maintain insomnia, including potentially within the infralimbic cortex, a substrate at the crossroads of threat habituation and sleep.

Sleep continuity, timing, quality, and disorder are associated with suicidal ideation and suicide attempts among college students.

Objective: To evaluate sleep continuity, timing, quality, and disorder in relation to suicidal ideation and attempts among college students. Participants: Eight hundred eighty-five undergraduates aged 18-25 in the southwestern United States. Methods: Participants completed questionnaires on sleep, suicide risk, mental health, and substance use. Differences in sleep variables were compared by lifetime and recent suicidal ideation and suicide attempts using covariate-adjusted and stepwise regression models. Results: A total of 363 (41.0%) individuals reported lifetime suicidal ideation, of whom 172 (47.4%) reported suicidal ideation in the last 3 months and 97 (26.7%) had attempted suicide in their lifetime. Sleep disturbances were prevalent among those with lifetime suicidal ideation or a lifetime suicide attempt. Insomnia was identified as the best predictor of recent suicidal ideation, but this relationship did not survive adjustment for covariates. Conclusions: Sleep continuity, quality, and sleep disorders are broadly associated with suicidal thoughts and behaviors among college students.

Social Jetlag and Other Aspects of Sleep Are Linked to Non-Suicidal Self-Injury Among College Students.

INTRODUCTION: Disrupted sleep is associated with non-suicidal self-injury (NSSI) in young adults, but many specific features of sleep continuity and timing have yet to be examined. Additionally, the psychological mechanisms linking sleep to NSSI are unclear. The present study evaluated 14 sleep variables as classifiers of lifetime or recent NSSI and examined potential confounding and mediating factors. METHODS: A sample of 885 college students provided measures of sleep continuity (e.g., duration, timing, fragmentation), nightmares, insomnia, and perceived sleep control. Lifetime and past 3-month NSSI were measured using a self-report version of the Columbia Suicide Severity Ratings Scale. Bidirectional stepwise regression identified significant sleep classifiers and subsequent models examined their associations with NSSI after adjusting for covariates and through potential psychological mediators. RESULTS: Only absolute social jetlag was associated with recent NSSI, even after adjusting for covariates, such that each additional hour difference between weekday and weekend sleep schedules was associated with a 17% greater risk of recent NSSI. Nightmares, weekend sleep efficiency, and perceived sleep control were associated with lifetime NSSI, although only weekend sleep efficiency remained associated after adjusting for covariates. Bootstrap mediations identified negative urgency as a partial mediator for recent and lifetime NSSI, and lack of premeditation and perceived burdensomeness as partial mediators for lifetime NSSI. CONCLUSIONS: The timing and consistency of young adults' sleep schedules may be of greater importance to NSSI among college students than insomnia or insufficient sleep. Future studies of sleep and NSSI should include these measures as potential risk factors. HIGHLIGHTSDifferences between weekday/weekend sleep timing are linked to recent NSSI.Negative urgency partially mediates poor sleep on recent and lifetime NSSI.Sleep shares a multifaceted relationship with NSSI risk in college students.

Sleep loss suicidal ideation: the role of trait extraversion.

Background: It is known that sleep disturbance is associated with increased suicidal thinking. Moreover, completed suicides, when adjusted for the proportion of the populace that is awake at a given time, are more probable during the late night/early morning hours. Despite these concerns, no studies have examined the role of trait-like individual differences in vulnerability to suicidal ideation during sleep deprivation or insomnia. In two separate studies, we examined whether the trait of extraversion is predictive of changes in suicidal thinking following two nights of sleep deprivation and among individuals meeting the criteria for insomnia. Methods: Study 1: Twenty-five healthy military personnel (20 males), ages 20-35 completed the NEO-PI-R Extraversion scale and the Suicidal Ideation (SUI) scale of the Personality Assessment Inventory (PAI). Participants completed 77 h of continuous sleep deprivation. After 56 h of sleep deprivation, participants completed the SUI scale a second time. We predicted a change in SUI scores from baseline extraversion. Study 2: 2,061 adults aged 18-79 (900 males) were divided into two groups based on the clinical threshold (≥ 10) on the Insomnia Severity Index (ISI) and completed measures of extraversion and depression, including the suicide item of the Patient Health Questionnaire-9 (PHQ9). Results: Study 1: After controlling for the caffeine group and changes in PAI Depression, Extraversion scores were used to predict changes in SUI scores using stepwise multiple linear regression. Higher Extraversion was significantly associated with increased non-clinical suicidal ideation following sleep loss, ß = 0.463, partial r = 0.512, p = 0.013. Study 2: After controlling for depression, the effect of insomnia on suicidal ideation was moderated by trait extraversion (p < 0.0001). Overall, the presence or absence of insomnia had little effect on individuals low in trait extraversion (i.e., introverts), but insomnia was associated with significantly higher suicidal ideation among high trait extraverted individuals. Conclusions: Higher trait extraversion was associated with increased vulnerability to suicidal ideation between rested baseline and total sleep deprivation and was associated with greater suicidal ideation among those meeting criteria for clinically severe insomnia. These findings point to a potential trait-like vulnerability factor that may further our understanding of sleep disruption in the phenomenology of suicide.

Insomnia and the Interpersonal Theory of suicide among civilians, service members, and veterans.

BACKGROUND: Insomnia is associated with suicide risk in civilian and military populations. Thwarted belongingness is proposed as a mediator of this relationship under the Interpersonal Theory of Suicide (IPTS). The present study explored how insomnia relates to suicidal ideation in conjunction with thwarted belongingness among civilians, Service members, and Veterans. METHODS: Data from the Military Suicide Research Consortium for N = 6556 individuals (6316 with non-missing suicidal ideation status) were divided into 4 subgroups: civilians, never deployed Service members, previously deployed Service members, and Veterans. Robust Poisson models evaluated the associations between insomnia severity/subtype and current suicidal ideation, with bootstrap mediation models assessing thwarted belongingness as a mediator. RESULTS: A 5-point increase in insomnia severity was associated with a 38% increased risk for current suicidal ideation among civilians, a 56% greater risk among never deployed Service members, an 83% greater risk among previously deployed Service members, and a 37% greater risk among Veterans. Moreover, active Service members showed greater associations between difficulty falling asleep and staying asleep with suicidal ideation than civilians. These associations were independent of covariates and only mediated by thwarted belongingness among Veterans. CONCLUSIONS: The relationship between insomnia and suicide is not purely explained by thwarted belongingness except among Veterans. Future research should explore additional psychological and neurobiological mechanisms connecting insomnia and suicidality.

Associations between Insomnia Symptoms and Anxiety Symptoms in Adults in a Community Sample of Southeastern Pennsylvania, USA.

Although insomnia is reliably associated with anxiety symptoms, aspects of insomnia may differentially relate to one anxiety symptom versus another. Therefore, treatment for insomnia comorbidity with anxiety might be individually tailored to optimize treatment response. Working from this hypothesis, we analyzed data from a survey of 1007 community-dwelling adults. Insomnia was measured using the Insomnia Severity Index (ISI), categorizing items as nighttime disturbances, daytime dysfunction, or self-perceived dissatisfaction. Anxiety symptoms were measured with the Generalized Anxiety Disorder 7-item questionnaire (GAD-7). Linear and binomial logistic regression were used and adjusted for covariates. Post hoc forward stepwise analyses determined which components of the insomnia contributed to individual anxiety symptoms. Significant associations between nighttime disturbance (ß = 0.88 [0.44, 1.3]), daytime dysfunction (ß = 1.30 [0.81, 1.80]), dissatisfaction (ß = 1.20 [0.60, 1.7]) and total GAD-7 score were maintained after adjusting for covariates. Nighttime disturbance was associated with excess worrying, restlessness, irritability, and fear of catastrophe. Daytime dysfunction was associated with all symptoms except for fear of catastrophe, and self-perceived dissatisfaction was associated with all symptoms except irritability. Stepwise analyses revealed that daytime dysfunction and dissatisfaction were most consistently related to anxiety symptoms.Greater attention should be paid to daytime dysfunction in patients with insomnia and anxiety, as improving daytime functioning may improve anxiety.

Diversity and determinants of bitterness, astringency, and fat content in cultivated Nacional and native Amazonian cocoa accessions from Ecuador.

Cocoa (Theobroma cacao L.) is the only tree that can produce cocoa. Cocoa beans are highly sought after by chocolate makers to produce chocolate. Cocoa can be fine aromatic, characterized by floral and fruity notes, or it can be described as standard cocoa with a more pronounced cocoa aroma and bitterness. In this study, the genetic and biochemical determinants of sensorial notes and nonvolatile compounds related to bitterness, astringency, fat content, and protein content will be investigated in two populations: a cultivated modern Nacional population and a population of cocoa accessions collected recently in the Ecuadorian South Amazonia area of origin of the Nacional ancestral variety. For this purpose, a genome-wide association study (GWAS) was carried out on both populations, with results of biochemical compounds evaluated by near-infrared spectroscopy (NIRS) assays and with sensory evaluations. Twenty areas of associations were detected for sensorial data especially bitterness and astringency. Fifty-three areas of associations were detected linked to nonvolatile compounds. A total of 81 candidate genes could be identified in the areas of the association.

Reversible Suppression of Fear Memory Recall by Transient Circadian Arrhythmia.

We tested the hypothesis that a temporary period of circadian arrhythmia would transiently impair recall of an aversive memory in Siberian hamsters (Phodopus sungorus). Unlike mice or rats, circadian arrhythmia is easily induced in this species by a one-time manipulation of their ambient lighting [i.e., the disruptive phase shift (DPS) protocol]. Hamsters were conditioned to associate footshocks with a shock chamber (context) and with a predictive auditory tone (cue), and then exposed to the DPS protocol. Following DPS, animals either became arrhythmic (ARR), reentrained to the light-dark cycle (ENT), or became arrhythmic for < 14 days before their circadian locomotor rhythms spontaneously recovered and reentrained (ARR-ENT). Tests for contextual memory showed that freezing was decreased 9-10 days post-DPS when both ARR and ARR-ENT groups were arrhythmic. Once ARR-ENT animals reentrained (day 41), however, freezing was elevated back to Pre-DPS levels and did not differ from those observed in ENT hamsters. ENT animals maintained high levels of freezing at both time points, whereas, freezing remained low in ARR hamsters. In contrast to contextual responses, cued responses were unaffected by circadian arrhythmia; all three groups exhibited elevated levels of freezing in response to the tones. The differential impact of circadian arrhythmia on contextual versus cued associative memory suggests that arrhythmia preferentially impacts memory processes that depend on the hippocampus.

The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology.

Sufficient sleep with minimal interruption during the circadian/biological night supports daytime cognition and emotional regulation. Conversely, disrupted sleep involving significant nocturnal wakefulness leads to cognitive and behavioral dysregulation. Most studies to-date have examined how fragmented or insufficient sleep affects next-day functioning, but recent work highlights changes in cognition and behavior that occur when someone is awake during the night. This review summarizes the evidence for day-night alterations in maladaptive behaviors, including suicide, violent crime, and substance use, and examines how mood, reward processing, and executive function differ during nocturnal wakefulness. Based on this evidence, we propose the Mind after Midnight hypothesis in which attentional biases, negative affect, altered reward processing, and prefrontal disinhibition interact to promote behavioral dysregulation and psychiatric disorders.

Sleep Deprivation Does Not Influence Photic Resetting of Circadian Activity Rhythms in Drosophila.

Previous investigations in humans and rodent animal models have assessed the interplay of sleep in the circadian system's phase responses to nighttime light exposure. The resulting data have been mixed, but generally support a modulatory role for sleep in circadian photic resetting (not an absolute requirement). Drosophila have been historically used to provide important insights in the sleep and circadian sciences. However, no experiments to date have evaluated how immediate sleep need or recent sleep history affects their pacemaker's phase readjustments to light. We did so in the current study by (1) forcing separate groups of animals to stay awake for 1 or 4 h after they were shown a broadspectrum pulse (15 min during the first half of the night, 950 lux), or (2) placing them on a restricted sleep schedule for a week before light presentation without any subsequent sleep disruption. Forced sleep restriction, whether acute or chronic, did not alter the size of light-induced phase shifts. These data are consistent with observations made in other diurnal animals and raise the possibility, more broadly, that phototherapies applied during sleep-such as may be necessary during the winter months-may still be efficacious in individuals experiencing sleep-continuity problems such as insomnia.

Current Insights into Optimal Lighting for Promoting Sleep and Circadian Health: Brighter Days and the Importance of Sunlight in the Built Environment.

This perspective considers the possibility that daytime's intrusion into night made possible by electric lighting may not be as pernicious to sleep and circadian health as the encroachment of nighttime into day wrought by 20th century architectural practices that have left many people estranged from sunlight.

Spectrophotometric properties of commercially available blue blockers across multiple lighting conditions.

Lenses that filter short-wavelength ("blue") light are commercially marketed to improve sleep and circadian health. Despite their widespread use, minimal data are available regarding their comparative efficacy in curtailing blue light exposure while maintaining visibility. Fifty commercial lenses were evaluated using five light sources: a blue LED array, a computer tablet display, an incandescent lamp, a fluorescent overhead luminaire, and sunlight. Absolute irradiance was measured at baseline and for each lens across the visual spectrum (380-780 nm), which allowed calculation of percent transmission. Transmission specificity was also calculated to determine whether light transmission was predominantly circadian-proficient (455-560 nm) or non-proficient (380-454 nm and 561-780 nm). Lenses were grouped by tint and metrics were compared between groups. Red-tinted lenses exhibited the lowest transmission of circadian-proficient light, while reflective blue lenses had the highest transmission. Orange-tinted lenses transmitted similar circadian-proficient light as red-tinted lenses but transmitted more non-circadian-proficient light, resulting in higher transmission specificity. Orange-tinted lenses had the highest transmission specificity while limiting biologically active light exposure in ordinary lighting conditions. Glasses incorporating these lenses currently have the greatest potential to support circadian sleep-wake rhythms.