Improve Daytime Alertness Research Articles

Effects of nature-adapted lighting solutions ("Virtual Sky") on subjective and objective correlates of sleepiness, well-being, visual and cognitive performance at the workplace.

Exposure to natural daylight benefits human well-being, alertness, circadian rhythms and sleep. Many workplaces have limited or no access to daylight. Thus, we implemented a light-panel ("Virtual Sky"), which reproduced nature-adapted light scenarios. In a laboratory office environment, three lighting scenarios were presented during the day: two lighting conditions with nature-adapted spectral light distributions, one with static and one with dynamic clouds, and a standard office lighting condition. We compared the impact of the three lighting scenarios on subjective and objective measures of alertness, cognitive performance, wellbeing, visual comfort, contrast sensitivity, and cortisol levels in 18 healthy young male volunteers in a within-participant cross-over study design. We found no evidence that an 8-h lighting scenario with static or dynamic clouds during the waking day (9am-5pm) was associated with any significant effect on objective and/or subjective alertness, cognitive performance and morning cortisol concentrations compared to standard workplace lighting. However, the dynamic light scenario was accompanied with lower levels of perceived tensionafter completing cognitive tasks and less effort to concentrate compared to the static lighting scenarios. Our findings suggest that apart from smaller effects on tension and concentration effort, nature-adapted lighting conditions did not improve daytime alertness and cognitive performance in healthy well-rested young participants, as compared to standard office lighting.

Association between Macronutrient Intake and Excessive Daytime Sleepiness: An Iso-Caloric Substitution Analysis from the North West Adelaide Health Study.

Epidemiological evidence on the association between macronutrient intake and excessive daytime sleepiness (EDS) is scarce. Using data from the North West Adelaide Health Study, we aimed to determine the association between iso-caloric substitution of macronutrients and EDS. Data from 1997 adults aged ≥ 24 years were analyzed. Daytime sleepiness was measured using the Epworth Sleepiness Scale, a score ≥ 11 was considered EDS. Dietary intake data were collected using a food frequency questionnaire. We determined absolute and relative energy intake based on consumption of saturated and unsaturated fats, protein, and carbohydrate. Odds ratios (ORs) were used to determine the associations using log-binomial logistic regression with and without iso-caloric substitution methods, and models were adjusted for confounders. The prevalence of EDS in the sample was 10.6%. After adjusting for potential confounders, substituting 5% energy intake from protein with an equal amount of saturated fat (OR = 1.57; 95% CI: 1.00–2.45) and carbohydrate (OR = 1.23; 95% CI: 0.92–1.65) increased the odds of EDS. When carbohydrate was substituted with saturated fat (OR = 1.27; 95% CI: 0.93–1.59), the odds of EDS were increased. The odds of EDS were lower when saturated fat was substituted with unsaturated fat (OR = 0.74; 95% CI: 0.51–1.06), protein (OR = 0.63; 95% CI: 0.41–0.99) or carbohydrate (OR = 0.79; 95% CI: 0.57–1.08). While these results were consistent over different iso-caloric substitution methods, inconsistent results were found with standard regression. While substitution of fat and carbohydrate with protein was inversely associated with EDS, substitution of protein with fat and carbohydrate was positively associated with EDS. Randomized trials are needed to confirm if dietary interventions can be used to improve daytime alertness in those with EDS.

A Look into Obstructive Sleep Apnea among Ethiopians.

Obstructive Sleep Apnea (OSA) is prevalent throughout the world. However, there are currently limited data concerning the prevalence of OSA in populations that originate from developing countries; the prevalence of OSA is expected to rise in these countries. OSA is poorly characterized amongst Ethiopians, and our study is the first to describe clinical characteristics of OSA among Ethiopians. We conducted a retrospective study of primarily Ethiopian patients at an internal medicine clinic in Rockville, Maryland. All patients (n=24) were evaluated for daytime sleepiness using the Epworth Sleepiness Scale (ESS) and received physical examinations and polysomnograms (PSG) by either portable monitoring (Itamar WatchPAT 200 device) or in-lab. Statistical analyses were performed in R. Linear regression model of Body-Mass Index (BMI) and Apnea-Hypopnea Index (AHI) indicated that for every 1-unit increase in BMI, there was a 0.8657-unit increase in AHI (p<0.05). Pearson's correlation coefficient indicateda positive linear relationship between BMI and AHI (0.47) (p<0.05). Adjusted linear regression model for AHI and oxygen saturation indicated that for every 1-unit increase of AHI, there was a 0.8452-unit decrease in nocturnal oxygen saturation (p<0.05). Pearson's correlation coefficient did not demonstrate significance between AHI and oxygen desaturation (p=0.062). Patients received either continuous positive airway pressure (CPAP) (n=15) or oral appliance therapy (n=3). All patients who complied with therapy reported improved sleep quality, snoring resolution, and improved daytime alertness. Practitioners in developing countries should suspect OSA in the right clinical setting and offer diagnostic and therapeutic services when available.

Living in Biological Darkness: Objective Sleepiness and the Pupillary Light Responses Are Affected by Different Metameric Lighting Conditions during Daytime.

Nighttime melatonin suppression is the most commonly used method to indirectly quantify acute nonvisual light effects. Since light is the principal zeitgeber in humans, there is a need to assess its strength during daytime as well. This is especially important since humans evolved under natural daylight but now often spend their time indoors under artificial light, resulting in a different quality and quantity of light. We tested whether the pupillary light response (PLR) could be used as a marker for nonvisual light effects during daytime. We also recorded the wake electroencephalogram to objectively determine changes in daytime sleepiness between different illuminance levels and/or spectral compositions of light. In total, 72 participants visited the laboratory 4 times for 3-h light exposures. All participants underwent a dim-light condition and either 3 metameric daytime light exposures with different spectral compositions of polychromatic white light (100 photopic lux, peak wavelengths at 435 nm or 480 nm, enriched with longer wavelengths of light) or 3 different illuminances (200, 600, and 1200 photopic lux) with 1 metameric lighting condition (peak wavelength at 435 nm or 480 nm; 24 participants each). The results show that the PLR was sensitive to both spectral differences between metameric lighting conditions and different illuminances in a dose-responsive manner, depending on melanopic irradiance. Objective sleepiness was significantly reduced, depending on melanopic irradiance, at low illuminance (100 lux) and showed fewer differences at higher illuminance. Since many people are exposed to such low illuminance for most of their day—living in biological darkness—our results imply that optimizing the light spectrum could be important to improve daytime alertness. Our results suggest the PLR as a noninvasive physiological marker for ambient light exposure effects during daytime. These findings may be applied to assess light-dependent zeitgeber strength and evaluate lighting improvements at workplaces, schools, hospitals, and homes.

Caffeine does not entrain the circadian clock but improves daytime alertness in blind patients with non-24-hour rhythms

Objective/BackgroundTotally blind individuals are highly likely to suffer from Non-24-Hour Sleep-Wake Disorder due to a failure of light to reset the circadian pacemaker in the suprachiasmatic nuclei. In this outpatient case series, we investigated whether daily caffeine administration could entrain the circadian pacemaker in non-entrained blind patients to alleviate symptoms of non-24-hour sleep–wake disorder. Patients/MethodsThree totally blind males (63.0 ± 7.5 years old) were studied at home over ~4 months. Urinary 6-sulphatoxymelatonin (aMT6s) rhythms were measured for 48 h every 1–2 weeks. Participants completed daily sleep–wake logs, and rated their alertness and mood using nine-point scales every ~2–4 h while awake on urine sampling days. Caffeine capsules (150 mg per os) were self-administered daily at 10 a.m. for approximately one circadian beat cycle based on each participant's endogenous circadian period τ and compared to placebo (n = 2) or no treatment (n = 1) in a single-masked manner. ResultsNon-24-h aMT6s rhythms were confirmed in all three participants (τ range = 24.32–24.57 h). Daily administration of 150 mg caffeine did not entrain the circadian clock. Caffeine treatment significantly improved daytime alertness at adverse circadian phases (p < 0.0001) but did not decrease the occurrence of daytime naps compared with placebo. ConclusionsAlthough caffeine was able to improve daytime alertness acutely and may therefore provide temporary symptomatic relief, the inability of caffeine to correct the underlying circadian disorder means that an entraining agent is required to treat Non-24-Hour Sleep–Wake Disorder in the blind appropriately.

Modafinil and Armodafinil in Schizophrenia

What Might Be the Positive Spin-Offs Associated With Modafinil or Armodafinil Use in This Patient? Racemic modafinil and its R-isomer armodafinil are approved treatments for the excessive daytime drowsiness associated with narcolepsy, shift work, and obstructive sleep apnea1; therefore, either of these drugs could benefit Mr P. In schizophrenia, modafinil and armodafinil have been prescribed, studied, or suggested for off-label indications such as antipsychotic-induced drowsiness,2–4 antipsychotic-related weight gain,5,6 negative symptoms,3,4,7,8 and cognitive impairment.3,4,7,9,10 Favorable results for these off-label indications have mostly been described in anecdotal reports; with a few exceptions, the randomized controlled trials have generally found no advantage for these drugs over placebo. In summary, modafinil and armodafinil could be expected to improve daytime alertness in Mr P, but, realistically, cognitive and negative symptoms could improve only to the extent that they were worsened specifically by the daytime drowsiness.

Alerting effects of daytime light exposure – a proposed link between light exposure and brain mechanisms

The effects of light on alertness have been shown several times and the proposed cause has been suppressed melatonin levels. The relation of melatonin and alertness applies at night but not by day when there is hardly any melatonin. Still, light can be used to improve daytime alertness, but how? This paper describes the brain mechanisms involved in light-induced daytime alertness and proposes a novel model of two parallel mechanisms. In addition to the well-established circadian pathway, it is suggested that light can use the amygdala in the limbic system to send signals to the cerebral cortex. The participation of the amygdala in light-induced alertness means that light is provoking and modulating emotions that induce alerting responses. The model is assembled from known relations but has not yet been verified as a functional system. The paper proposes methods to test the model.

Depression and associated sleep disturbances: patient benefits with agomelatine

Summary The essential linkage of sleep disturbance and clinical depression has long been recognized. Almost all patients with major depression report some form of sleep difficulty including insomnia, oversleeping, and poor-quality sleep. Some have argued that these changes in the sleep-wake cycle are actually aspects of a more fundamental alteration in circadian rhythms. Antidepressants that reduce restless sleep and awakenings and improve daytime alertness are desirable. It also appears that compounds that “rearrange” the intensity of rapid eye movement and slow-wave sleep may provide the best clinical effects on sleep besides antidepressant clinical efficacy. Agomelatine, a new antidepressant with melatonergic activity and 5-HT 2c antagonist properties, has shown its efficacy in major depression. Beyond this antidepressant efficacy, agomelatine demonstrates sleep electroencephalographic changes consistent with desirable sleep architecture improvements, as well as improved subjective sleep quality within the first week of administration accompanied by an improvement in daytime alertness.

Continuous positive airway pressure for sleep-related breathing disorders in multiple system atrophy: long-term acceptance

Background and purpose To assess the long-term acceptance of non-invasive nasal continuous positive air pressure (CPAP) in multiple system atrophy (MSA) patients with polysomnographic (PSG)-confirmed sleep apneas and/or nocturnal stridor. Patients and methods Sleep-related breathing disorders were investigated by PSG in 22 MSA patients in whom stridor and sleep-related respiratory disturbances were clinically suspected. Patients in whom the first PSG disclosed either a sleep apnea/hypopnea index (AHI)≥10 or stridor with or without apneas underwent a second PSG for CPAP titration. Results Three patients presented with an obstructive sleep apnea syndrome without stridor, whereas 15 patients presented stridor occurring alone or accompanied by apneas. Twelve patients pursued CPAP. Two severely disabled patients died a few days after CPAP initiation, and five discontinued CPAP because of discomfort. One patient died after 17 months of follow-up. Since the onset of CPAP, the four remaining patients reported more efficacious sleep and improved daytime alertness. These patients had significantly less severe disease at the time of CPAP initiation. Age, disease duration, the presence of sleep complaints, excessive daytime somnolence (EDS) and AHI did not account for CPAP compliance. Conclusion The severity of motor impairment at the initiation of treatment appears to be the most significant limiting factor for CPAP long-term acceptance.

SLEEP DISTURBANCE IN BATTERED WOMEN LIVING IN TRANSITIONAL HOUSING

This study describes objective and subjective sleep in a convenience sample of 29 battered women living in specialized transitional housing programs compared to 30 women living in their own stable home environment. Compared to healthy controls, battered women living in transitional housing experienced longer sleep onset latencies by both subjective and objective measures and higher percentage of time awake during the night by objective measure. Poor sleep quality may reflect the relative contributions of less total sleep time, difficulty falling asleep, and more awakenings during the night rather than just one aspect of disturbed sleep. Findings suggest that battered women in transitional housing programs may improve daytime alertness and benefit from interventions directed toward reducing sleep onset latency as well as increasing total sleep time.

The value of melatonin for sleep disorders occurring post-head injury: a pilot RCT

Primary objective: Whilst there is data to support the use of Melatonin in treating disorders of the sleep–wake cycle, so far there is little published evidence on the efficacy of Melatonin in treating the prevalent condition of post-TBI sleep disturbance.Research design: The present work used a randomized double-blind controlled cross-over trial to compare Melatonin (5 mg) and Amitriptyline (25 mg) in a small sample of TBI patients presenting with chronic sleep disturbance.Main outcome and results: No differences in sleep latency, duration, quality or daytime alertness were found for either drug compared to baseline using significance testing. However, effect sizes revealed some encouraging changes. Patients on Melatonin reported improved daytime alertness compared to baseline. On Amitriptyline, patients reported increased sleep duration compared to baseline.Conclusions: The study provides preliminary evidence for the value of Melatonin and Amitriptyline in treating sleep disorder post-TBI. There were no adverse drug effects. Suggestions are made for ongoing investigation for the treatment of this prevalent condition.

A preliminary study of the effects of correction of anemia with recombinant human erythropoietin therapy on sleep, sleep disorders, and daytime sleepiness in hemodialysis patients (The SLEEPO study).

End-stage renal disease (ESRD) is commonly associated with complaints of disturbed sleep and sleep disorders, frequently related to periodic limb movements in sleep (PLMS) or sleep apnea that may result in daytime sleepiness and other sequelae. Improvements in quality of life, including subjective sleep quality, have been reported in ESRD patients treated with recombinant human erythropoietin (rHuEPO). We investigated the objective effects of normalizing hematocrit on sleep disorders, sleep patterns, and daytime ability to remain awake in ESRD patients. Ten hemodialysis patients with sleep complaints while on rHuEPO therapy were studied by polysomnography while moderately anemic (mean hematocrit, 32.3%) and again when hematocrit was normalized (mean hematocrit, 42.3%) by increased rHuEPO dosing. Sleep patterns and associated parameters were monitored. Delivered dialysis dose and iron storage factors were monitored. Maintenance of Wakefulness Testing (MWT) was performed to assess daytime alertness/sleepiness. All 10 subjects experienced highly statistically significant reductions in the total number of arousing PLMS (P = 0.002). Nine of 10 subjects showed reductions in both the Arousing PLMS Index (P < 0.01) and the PLMS Index (P = 0.03) when hematocrit was normalized. Measures of sleep quality showed trends to improved quality of sleep. MWT demonstrated significant improvement in the length of time patients were able to remain awake (9.7 versus 17.1 minutes; P = 0.04). RHuEPO therapy with full correction of anemia reduces PLMS, arousals from sleep, and sleep fragmentation while allowing for more restorative sleep and improved daytime alertness. These findings may explain one mechanism for the improved quality-of-life parameters reported in ESRD patients treated with rHuEPO.

Tolerance and intolerance to continuous positive airway pressure.

Nasal continuous positive airway pressure (CPAP) is the most effective and widely used therapy for obstructive sleep apnea. As with any chronic therapy, long-term compliance has a significant impact on its effectiveness. Only about half of patients use CPAP for more than half the night on five or more nights per week. Approximately 4 hours of CPAP therapy per night appears to significantly improve daytime alertness and performance. Four hours of therapy also seems to improve sleep-disordered breathing for the remainder of the night. Patient education and close follow-up and intervention appear to improve long-term tolerance. Autotitration CPAP or bilevel positive airway pressure systems are no more effective or better tolerated than conventional CPAP therapy. They may be useful options if patients have been unable to tolerate conventional CPAP therapy.

Normal sleep, disturbed sleep, transient and persistent insomnia.

There are three fundamental principles for understanding sleep; the sleeping brain is not a resting brain, the sleeping brain functions in a different manner from the waking brain and the activity and work of the sleeping brain are purposeful. The sleeping brain does fail and this failure is manifest in a variety of clinical symptoms; all sleep complaints should be taken seriously and investigated. Transient insomnia is uniformly associated with objective sleep disturbances which have been documented following phase shifts of the major sleep period such as that caused by transmeridian travel. However, the degree to which the individual responds to these factors is variable. There is a consensus that sleep medications are indicated for transient and short-term insomnia. Benzodiazepine hypnotics are commonly used to induce and maintain sleep, and improve daytime alertness.