Prevention and control of jet lag symptoms and temporary impairment of cognitive function with Pycnogenol® in healthy individuals and in hypertensives

BACKGROUND

The aim of this registry study was to evaluate the efficacy of Pycnogenol® in controlling signs/symptoms and temporary impairment of cognitive function (COFU) associated with jet lag. Previous flight studies have shown a decrease in the level of jet lag symptoms with Pycnogenol®. The control of jet lag signs/symptoms appeared to be correlated with flight-related microangiopathy and peripheral edema. Pycnogenol® - a standardized extract from the bark of French maritime pine - has significant antiedema, anti-inflammatory and antioxidant properties.

METHODS

A group of subjects flying east in economy class for 10-12 hours used Pycnogenol® 150 mg/day and a similar group without supplementation served as controls. A subgroup of mild hypertensive subjects using a single ACE inhibitor was also included.

RESULTS

One hundred twenty-seven subjects completed the study. Of the participants, 48 were aviation professionals like pilots, flight attendants or air company staff - 24 of them took Pycnogenol® and 24 served as controls. Forty-seven study participants were frequent flyers and non-staff professionals, 25 of which took Pycnogenol® and 22 served as controls. In addition, a group of 32 subjects with mild hypertension was included, 16 took Pycnogenol® and 16 served as controls. No side effects and a good tolerability were observed. The registry groups were comparable for baseline characteristics. Eastbound flights' duration was 11.22±0.4 hours in supplemented subjects and 11.14±0.32 in controls. Dropouts were due to logistical problems. Post flight Visual Analogue Scale (VAS) scores were significantly lower in all Pycnogenol® groups, including hypertensives for all signs and symptoms of jet lag compared to controls, showing prevention and improvement of jet lag symptoms. The duration of any sign/symptom of jet lag with Pycnogenol® intake was significantly shorter (P<0.05) post-flight compared to controls (P<0.05). The number of nights of altered/disturbed sleep was also lower in the Pycnogenol® groups compared to controls. Leg edema was present in almost all subjects with different degrees especially in the hypertensive group. The increase in ankle circumference before and after flight was significantly lower with Pycnogenol® compared to controls (P<0.05). After the flight, average scores of the single COFU tasks were significantly higher in the Pycnogenol® groups compared to controls, showing preserved cognitive function.

CONCLUSIONS

In conclusion, in this registry study Pycnogenol® was effective in preventing jet lag-related symptoms and preserving cognitive functions without tolerability problems. These observations should be tested in a larger group of subjects including complex individuals prone to edema (i.e. diabetics, hypertensive or older patients).

Entrainment to gradual vs. immediate 8-hour phase advance shifts with and without short-wavelength enriched polychromatic green light

OBJECTIVES

For optimal health and well-being the sleep episode and the circadian timing system should be properly aligned. We evaluated the effectiveness of different dynamic light and sleep/wake shift schedules for rapid circadian entrainment following an 8-hour advance of sleep.

METHODS

Forty-three healthy participants completed an 8-day inpatient protocol in which the 8-hour sleep episode was advanced by 8 hours. Participants were assigned to one of five conditions: (1) dim ambient WHITE light and GRADUAL shift in which the sleep episode was incrementally advanced over 5days; (2) dim GREEN, short-wavelength (∼504 nm) polychromatic light and GRADUAL shift; (3) dim WHITE light and SLAM shift, including an abrupt 8-hour advance on day 3 following an extended 32-hour wake episode; (4) GREEN light and SLAM shift; or (5) COMBINED (higher illuminance WHITE plus GREEN) light and modified SLAM shift with 2 short naps scheduled on the day prior to the abrupt advance. Phase shifts of the plasma dim light melatonin onset and sleep measures were compared to examine effects of protocol condition.

RESULTS

After 5days, the COMBINED light/modified SLAM shift condition showed larger phase advances of dim light melatonin onset (4.02 ± 1.13 hours) compared to the other 4 conditions (range 1.50 ± 0.96-2.83 ± 2.23 hours; p < .05) and resulted in increased REM sleep duration and fewer sleep disruptions.

CONCLUSIONS

Consideration of the type of shift and the illuminance and wavelength of light may assist in designing lighting countermeasures to sleep and circadian disruption, which has implications for jetlag, shiftwork, and circadian rhythm sleep disorders.

The role of the fronto-parietal network in modulating sustained attention under sleep deprivation: an functional magnetic resonance imaging study

Objective

The intricate relationship between sleep deprivation (SD) and cognitive performance has long been a subject of research. Our study offers a novel angle by closely examining the neurobiological underpinnings of sustained attention deficits through the lens of the fronto-parietal network (FPN). Using state-of-the-art imaging techniques, we delve into the changes in spontaneous brain activity after SD and explore their associations with performance on the psychomotor vigilance task (PVT).

Methods

We conducted an elaborate investigation involving 64 healthy, right-handed participants who underwent resting-state functional MRI scans before and after experiencing 24 h of sleep deprivation. Employing sophisticated statistical analyses, we scrutinized the changes in fractional amplitude of low-frequency fluctuations (fALFF) through paired t-tests. Pearson correlation analyses were then applied to dissect the associations between these neurobiological shifts and behavioral outcomes in PVT.

Results

The study yielded remarkable findings, revealing a dramatic decrease in fALFF values within critical areas of the FPN following SD. These alterations predominantly occurred in the frontal and parietal gyri and were inversely correlated with PVT performance metrics. Furthermore, we discovered that baseline fALFF values in the left dorsolateral prefrontal cortex (DLPFC) have the potential to serve as compelling neurobiological markers, with high discriminatory power in identifying individual responses to the adverse effects of SD on cognitive performance.

Conclusion

Our groundbreaking research underscores the pivotal role that the FPN plays in modulating attention and executive function, especially under the challenging conditions brought about by sleep deprivation. The findings offer critical insights that could shape the way we understand, assess, and potentially mitigate the cognitive impacts of SD, setting the stage for future research in this riveting domain.

Dim light melatonin onset following simulated eastward travel is earlier in young males genotyped as PER35/5 than PER34/4

Inter-individual variability exists in recovery from jetlag following travel across time zones. Part of this variation may be due to genetic differences at the variable number tandem repeat (VNTR) polymorphism of the PERIOD3 (PER3) gene as this polymorphism has been associated with chronotype and sleep, as well as sensitivity to blue light on melatonin suppression. To test this hypothesis we conducted a laboratory-based study to compare re-entrainment in males genotyped as PER3^4/4 (n = 8) and PER3^5/5 (n = 8) following simulated eastward travel across six time zones. The recovery strategy included morning blue-enriched light exposure and appropriately-timed meals during the first 24 h after simulated travel. Dim light melatonin onset (DLMO), sleep characteristics, perceived sleepiness levels (Stanford Sleepiness Scale), and resting metabolic parameters were measured during constant routine periods before and after simulated travel. While DLMO time was similar between the two groups prior to simulated eastward travel (p = .223), it was earlier in the PER3^5/5 group (17h23 (17h15; 17h37)) than the PER3^4/4 group (18h05 (17h53; 18h12)) afterwards (p = .046). During resynchronisation, perceived sleepiness and metabolic parameters were similar to pre-travel in both groups but sleep was more disturbed in the PER3^5/5 group (total sleep time: p = .008, sleep efficiency: p = .008, wake after sleep onset: p = .023). The PER3 VNTR genotype may influence the efficacy of re-entrainment following trans-meridian travel when blue-enriched light exposure is incorporated into the recovery strategy on the first day following travel.

Association between Self-Reported Prior Night's Sleep and Single-Task Gait in Healthy, Young Adults: A Study Using Machine Learning

Failure to obtain the recommended 7−9 h of sleep has been associated with injuries in youth and adults. However, most research on the influence of prior night’s sleep and gait has been conducted on older adults and clinical populations. Therefore, the objective of this study was to identify individuals who experience partial sleep deprivation and/or sleep extension the prior night using single task gait. Participants (n = 123, age 24.3 ± 4.0 years; 65% female) agreed to participate in this study. Self-reported sleep duration of the night prior to testing was collected. Gait data was collected with inertial sensors during a 2 min walk test. Group differences (<7 h and >9 h, poor sleepers; 7−9 h, good sleepers) in gait characteristics were assessed using machine learning and a post-hoc ANCOVA. Results indicated a correlation (r = 0.79) between gait parameters and prior night’s sleep. The most accurate machine learning model was a Random Forest Classifier using the top 9 features, which had a mean accuracy of 65.03%. Our findings suggest that good sleepers had more asymmetrical gait patterns and were better at maintaining gait speed than poor sleepers. Further research with larger subject sizes is needed to develop more accurate machine learning models to identify prior night’s sleep using single-task gait.

The Common Effects of Sleep Deprivation on Human Long-Term Memory and Cognitive Control Processes

Sleep deprivation is known to have adverse effects on various cognitive abilities. In particular, a lack of sleep has been reported to disrupt memory consolidation and cognitive control functions. Here, focusing on long-term memory and cognitive control processes, we review the consistency and reliability of the results of previous studies of sleep deprivation effects on behavioral performance with variations in the types of stimuli and tasks. Moreover, we examine neural response changes related to these behavioral changes induced by sleep deprivation based on human fMRI studies to determine the brain regions in which neural responses increase or decrease as a consequence of sleep deprivation. Additionally, we discuss about the possibility that light as an environmentally influential factor affects our sleep cycles and related cognitive processes.

Early life circadian rhythm disruption in mice alters brain and behavior in adulthood

Healthy sleep supports robust development of the brain and behavior. Modern society presents a host of challenges that can impair and disrupt critical circadian rhythms that reinforce optimal physiological functioning, including the proper timing and consolidation of sleep. While the acute effects of inadequate sleep and disrupted circadian rhythms are being defined, the adverse developmental consequences of disrupted sleep and circadian rhythms are understudied. Here, we exposed mice to disrupting light–dark cycles from birth until weaning and demonstrate that such exposure has adverse impacts on brain and behavior as adults. Mice that experience early-life circadian disruption exhibit more anxiety-like behavior in the elevated plus maze, poorer spatial memory in the Morris Water Maze, and impaired working memory in a delayed match-to-sample task. Additionally, neuron morphology in the amygdala, hippocampus and prefrontal cortex is adversely impacted. Pyramidal cells in these areas had smaller dendritic fields, and pyramidal cells in the prefrontal cortex and hippocampus also exhibited diminished branching orders. Disrupted mice were also hyperactive as adults, but otherwise exhibited no alteration in adult circadian locomotor rhythms. These results highlight that circadian disruption early in life may have long lasting and far-reaching consequences for the development of behavior and the brain.

Potential Effect of the Circadian Clock on Erectile Dysfunction

The circadian rhythm is an internal timing system, which is generated by circadian clock genes. Because the circadian rhythm regulates numerous cellular, behavioral, and physiological processes, organisms have evolved with intrinsic biological rhythms to adapt the daily environmental changes. A variety of pathological events occur at specific times, while disturbed rhythms can lead to metabolic syndrome, vascular dysfunction, inflammatory disorders, and cancer. Therefore, the circadian clock is considered closely related to various diseases. Recently, accumulated data have shown that the penis is regulated by the circadian clock, while erectile function is impaired by an altered sleep-wake cycle. The circadian rhythm appears to be a novel therapeutic target for preventing and managing erectile dysfunction (ED), although research is still progressing. In this review, we briefly summarize the superficial interactions between the circadian clock and erectile function, while focusing on how disturbed rhythms contribute to risk factors of ED. These risk factors include NO/cGMP pathway, atherosclerosis, diabetes mellitus, lipid abnormalities, testosterone deficiency, as well as dysfunction of endothelial and smooth muscle cells. On the basis of recent findings, we discuss the potential role of the circadian clock for future therapeutic strategies on ED, although further relevant research needs to be performed.

The potential impacts of circadian rhythm disturbances on male fertility

A circadian rhythm is an internalized timing system that synchronizes the cellular, behavioral, and physiological processes of organisms to the Earth's rotation. Because all physiological activities occur at a specific time, circadian rhythm disturbances can lead to various pathological disorders and diseases. Growing evidence has shown that the circadian clock is tightly connected to male fertility, and circadian perturbations contribute to infertility. The night shiftwork, insufficient sleep, and poor sleep quality are common causes of circadian disturbances, and many studies have reported that they impair sperm quality and increase the risk of male infertility. However, research on the impacts of light, body temperature, and circadian/circannual rhythms is relatively lacking, although some correlations have been demonstrated. Moreover, as the index of sperm quality was diverse and study designs were non-uniform, the conclusions were temporarily inconsistent and underlying mechanisms remain unclear. A better understanding of whether and how circadian disturbances regulate male fertility will be meaningful, as more scientific work schedules and rational lifestyles might help improve infertility.

Impact of Time-Restricted Feeding to Late Night on Adaptation to a 6 h Phase Advance of the Light-Dark Cycle in Mice

In modern society, more and more people suffer from circadian disruption, which in turn affects health. But until now, there are no widely accepted therapies for circadian disorders. Rhythmic feeding behavior is one of the most potent non-photic zeitgebers, thus it has been suggested that it was important to eat during specific periods of time (time-restricted feeding, TRF) so that feeding is aligned with environmental cues under normal light/dark conditions. Here, we challenged mice with a 6 h advanced shift, combined with various approaches to TRF, and found that food restricted to the second half of the nights after the shift facilitated adaptation. This coincided with improved resilience to sepsis. These results raise the possibility of reducing the adverse responses to jet lag by subsequent timing of food intake.

Regulation of Olfactory Associative Memory by the Circadian Clock Output Signal Pigment-Dispersing Factor (PDF)

Dissociation between the output of the circadian clock and external environmental cues is a major cause of human cognitive dysfunction. While the effects of ablation of the molecular clock on memory have been studied in many systems, little has been done to test the role of specific clock circuit output signals. To address this gap, we examined the effects of mutations of Pigment-dispersing factor (Pdf) and its receptor, Pdfr, on associative memory in male and female Drosophila Loss of PDF signaling significantly decreases the ability to form associative memory. Appetitive short-term memory (STM), which in wild-type (WT) is time-of-day (TOD) independent, is decreased across the day by mutation of Pdf or Pdfr, but more substantially in the morning than in the evening. This defect is because of PDFR expression in adult neurons outside the core clock circuit and the mushroom body (MB) Kenyon cells (KCs). The acquisition of a TOD difference in mutants implies the existence of multiple oscillators that act to normalize memory formation across the day for appetitive processes. Interestingly, aversive STM requires PDF but not PDFR, suggesting that there are valence-specific pathways downstream of PDF that regulate memory formation. These data argue that the circadian clock uses circuit-specific and molecularly diverse output pathways to enhance the ability of animals to optimize responses to changing conditions.SIGNIFICANCE STATEMENT From humans to invertebrates, cognitive processes are influenced by organisms' internal circadian clocks, the pace of which is linked to the solar cycle. Disruption of this link is increasingly common (e.g., jetlag, social jetlag disorders) and causes cognitive impairments that are costly and long lasting. A detailed understanding of how the internal clock regulates cognition is critical for the development of therapeutic methods. Here, we show for the first time that olfactory associative memory in Drosophila requires signaling by Pigment-dispersing factor (PDF), a neuromodulatory signaling peptide produced only by circadian clock circuit neurons. We also find a novel role for the clock circuit in stabilizing appetitive sucrose/odor memory across the day.

Jet Lag Recovery and Memory Functions Are Correlated with Direct Light Effects on Locomotion

Jet lag is a circadian disruption that affects millions of people, resulting, among other things, in extreme sleepiness and memory loss. The hazardous implications of such effects are evident in situations in which focus and attention are required. Remarkably, there is a limited understanding of how jet lag recovery and associated memory loss vary year round under different photoperiods. Here we show, using different cycles representing winter, summer, and equinox in male mice, that jet lag recovery and memory vary significantly with photoperiod changes. We uncover a positive correlation of acute light effects on circadian-driven locomotion (known as negative masking) with photoentrainment speed and memory enhancement during jet lag. Specifically, we show that enhancing or reducing negative masking is correlated with better or worse memory performance, respectively. This study indicates that in addition to timed-light exposure for phase shifting, the negative masking response could also be biologically relevant when designing effective treatments of jet lag.

Efficacy of Tasimelteon (HETLIOZ®) in the Treatment of Jet Lag Disorder Evaluated in an 8-h Phase Advance Model; a Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Background: Most travelers experience Jet Lag Disorder (JLD) symptoms due to misalignment of their circadian rhythms with respect to the new time zone. We assessed the efficacy and safety of tasimelteon (HETLIOZ®) in healthy participants using a laboratory model of JLD induced by an 8-h phase advance of the sleep-wake cycle (JET8 Study). We hypothesized that tasimelteon treatment in participants experiencing JLD would cause increased sleep time, increased next-day alertness, and reduced next-day sleepiness.

Methods: We undertook a randomized, double-blind, placebo-controlled trial in 12 US clinical research sleep centers. We screened healthy adults ages 18–73 years, who were eligible for the randomization phase of JET8 if they typically went to bed between 21:00 and 01:00, slept between 7 and 9 h each night, and slept at a consistent bedtime. We used block randomization stratified by site to assign participants (1:1) to receive a single oral dose of tasimelteon (20 mg) or placebo 30 min before their 8-h phase-advanced bedtime. The primary endpoint was Total Sleep Time in the first 2/3 of the night (TST_2/3), which was measured by polysomnography during the 8-h sleep episode, and assessed in the intent-to-treat population. The trial is completed and registered with ClinicalTrials.gov, NCT03373201.

Results: Between October 16, 2017 and January 17, 2018, we screened 607 healthy participants for JET8, of whom 320 (53%) were assigned to receive tasimelteon (n = 160) or placebo (n = 160). Tasimelteon treatment increased TST_2/3 (primary endpoint) by 60.3 min (95%CI 44.0 to 76.7, P < 0.0001) and whole night TST by 85.5 min (95% CI 64.3 to 106.6, P < 0.0001), improved next day alertness, next day sleepiness, and shortened latency to persistent sleep by −15.1 min (95% CI −26.2 to −4.0, P = 0.0081).

Conclusion: A single dose of tasimelteon improves the primary symptoms of JLD, including nighttime insomnia and next day functioning among participants in a laboratory model of JLD simulating eastward trans-meridian travel by inducing an 8-h phase advance of the sleep-wake cycle.

Therapeutic potential of nicotinamide adenine dinucleotide (NAD)

Nicotinamide adenine nucleotide (NAD) is a small ubiquitous hydrophilic cofactor that participates in several aspects of cellular metabolism. As a coenzyme it has an essential role in the regulation of energetic metabolism, but it is also a cosubstrate for enzymes that regulate fundamental biological processes such as transcriptional regulation, signaling and DNA repairing among others. The fluctuation and oxidative state of NAD levels regulate the activity of these enzymes, which is translated into marked effects on cellular function. While alterations in NAD homeostasis are a common feature of different conditions and age-associated diseases, in general, increased NAD levels have been associated with beneficial health effects. Due to its therapeutic potential, the interest in this molecule has been renewed, and the regulation of NAD metabolism has become an attractive target for drug discovery. In fact, different approaches to replenish or increase NAD levels have been tested, including enhancement of biosynthesis and inhibition of NAD breakdown. Despite further research is needed, this review provides an overview and update on NAD metabolism, including the therapeutic potential of its regulation, as well as pharmacokinetics, safety, precautions and formulation challenges of NAD supplementation.

Acute moderate-intensity exercise improves 24-h sleep deprivation-induced cognitive decline and cerebral oxygenation: A near-infrared spectroscopy study

We evaluated the effects of moderate-intensity exercise in improving the decline in cognitive performance induced by a 24-h period of acute sleep deprivation (SD). We hypothesized that the positive effect of exercise is mediated by increased oxygenation (measured using near-infrared spectroscopy) of the dorsolateral prefrontal cortex (DLPFC). Cognitive performance was measured using the reaction time and interference scores of the Stroop colour and word test, in 12 healthy adults (eight males, 21.1 ± 0.3 years-old), at pre- and post-exercise. Cognitive scores were compared under two conditions: rested wakefulness (RW) and 24-h SD. The exercise consisted of 20-min of ergometer cycling at an intensity of 60 % VO_2peak. Oxygenation to the DLPFC increased, at 12 min after exercise onset, compared to the baseline and was maintained until the end of the exercise in both RW and SD conditions (P < 0.01). The change in RT correlated with sleepiness (P < 0.05), with no correlation for the interference score and oxygenation. Taken together, moderate-intensity exercise reverses SD-induced cognitive decline.

Role of the Circadian Clock in the Metabolic Syndrome and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized nations and is strongly associated with the metabolic syndrome. The prevalence of NAFLD continues to rise along with the epidemic of the metabolic syndrome. Metabolic homeostasis is linked to the circadian clock (rhythm), with multiple signaling pathways in organs regulated by circadian clock genes, and recent studies of circadian clock gene functions suggest that disruption of the circadian rhythm is associated with significant morbidity and mortality, including the metabolic syndrome. In the industrialized world, various human behaviors and activities such as work and eating patterns, jet lag, and sleep deprivation interfere with the circadian rhythm, leading to perturbations in metabolism and development of the metabolic syndrome. In this review, we discuss how disruption of the circadian rhythm is associated with various metabolic conditions that comprise the metabolic syndrome and NAFLD.

Sleep disorders in adolescents and young adults: Insights into types, relationship to obesity and high altitude and possible lines of management

A sleep disorder is a medical disorder of the sleep pattern of a person that may be serious enough to interfere with normal physical, mental and emotional functioning. Disruptions in sleep can be caused by a variety of causes, from teeth grinding to night terrors. Sleep disorders are usually prevalent among adolescents and young adults, possibly due to factors related to life style, dietary habits, hormonal and emotional disturbances. Other factors that may precipitate sleep disorders include environmental, psychological and genetic factors. Sleep disorders may lead to serious psychological and mood disorders and may even affect the immune system. Management of sleep disorders depends on amelioration of the precipitating factors and the use of certain drugs that may help to restore the normal sleep-wake cycle. This review sheds light on sleep disorders in adolescents and young adults regarding their types, etiology, dangers and possible lines of management.

Chronic social defeat stress suppresses locomotor activity but does not affect the free-running circadian period of the activity rhythm in mice

In mammals, daily rhythms in behavior and physiology are under control of an endogenous clock or pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN assures an optimal temporal organization of internal physiological process and also synchronizes rhythms in physiology and behavior to the cyclic environment. The SCN receives direct light input from the retina, which is capable of resetting the master clock and thereby synchronizes internally driven rhythms to the external light-dark cycle. In keeping with its function as a clock and pacemaker, the SCN appears to be well buffered against influences by other stimuli and conditions that contain no relevant timing information, such as acute stressors. On the other hand, it has been suggested that chronic forms of stress may have gradually accumulating effects that can disturb normal clock function and thereby contribute to stress-related disorders. Therefore, in the present study we investigated whether chronic intermittent social stress affects the endogenous period and phase of the free-running activity rhythm in mice. Adult male mice were maintained in constant dim red light conditions and exposed to a daily 20 min social defeat stress session for 10 consecutive days, either during the first half of their activity phase or the first half of their resting phase. The overall amount of running wheel activity was strongly suppressed during the 10 days of social defeat, to about 50% of the activity in non-defeated control mice. Activity levels gradually normalized during post-defeat recovery days. Despite the strong suppression of activity in defeated animals, the endogenous free-running circadian period of the activity rhythm and the phase of activity onset were not affected. These findings are thus in agreement with earlier studies suggesting that the circadian pacemaker in the SCN that is driving the rhythmicity in activity is well-protected against stress. Even severe social defeat stress for 10 consecutive days, which has a major effect on the levels of activity, does not affect the pace of the endogenous clock.

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Chronic intermittent social defeat stress strongly reduces locomotor activity in mice.

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Chronic intermittent social defeat stress does not affect the circadian period and phase of the free-running activity rhythm under constant conditions.

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Social defeat stress does not appear to affect the endogenous clock in the SCN driving the rhythmicity in activity.

Risk management of free radicals involved in air travel syndromes by antioxidants

Frequent air travelers and airplane pilots may develop various types of illnesses. The environmental risk factors associated with air travel syndromes (ATS) or air travel-related adverse health outcomes raised concerns and need to be assessed in the context of risk management and public health. Accordingly, the aim of the present review was to determine ATS, risk factors, and mechanisms underlying ATS using scientific data and information obtained from Medline, Toxline, and regulatory agencies. Additional information was also extracted from websites of organizations, such as the International Air Transport Association (IATA), International Association for Medical Assistance to Travelers (IAMAT), and International Civil Aviation Organization (ICAO). Air travelers are known to be exposed to environmental risk factors, including circadian rhythm disruption, poor cabin air quality, mental stress, high altitude conditions, hormonal dysregulation, physical inactivity, fatigue, biological infections, and alcoholic beverage consumption. Consequences of ATS attributed to air travel include sleep disturbances (e.g., insomnia), mental/physical stress, gastrointestinal disorders, respiratory diseases, circulatory-related dysfunction, such as cardiac arrest and thrombosis and, at worst, mechanical and terrorism-related airplane crashes. Thus safety measures in the cabin before or after takeoff are undertaken to prevent illnesses or accidents related to flight. In addition, airport quarantine systems are strongly recommended to prepare for any ultimate adverse circumstances. Routine monitoring of environmental risk factors also needs to be considered. Frequently, the mechanisms underlying these adverse manifestations involve free radical generation. Therefore, antioxidant supplementation may help to reduce or prevent adverse outcomes by mitigating health risk factors associated with free radical generation.

Assessment of anxiety in adolescents involved in a study abroad program: a prospective study

Objective The aim of the study was to measure the effects on levels of anxiety in healthy teenagers caused by a temporary change of country and school during a study abroad program. Methods In a prospective study we gathered the data from six anxiety level related tests on high school participants in a study abroad program (age 15-17, n = 364, M 172, F 192). These volunteer participants were divided into two separate groups: with self-reported elevated levels of anxiety (n = 111; YES-group) and with self-reported normal levels of anxiety (n = 253; NO-group). Two control groups of schoolchildren drawn from two local schools were used for comparison (n = 100 each). Three tests were subjective, i.e. self-fill-out tests. The next three tests were objective psychological or neurophysiological tests designed to estimate reflex control, concentration and a feeling for the passage of time. Results The initial mean anxiety level score among the 364 participants was 41.5 ± 16.7 (min 16, max 80) on 5-110 scale. For the YES-group the score was 56.5 ± 15.9, and for the NO-group the score was 34.7 ± 17.4 (p = 0.05). The retesting after they had been in the same place for 7 weeks revealed that the mean anxiety level score of the participants decreased to 37.4 ± 16.9 (min 15, max 72). For the YES-group the score significantly decreased to 39.3 ± 15.5, and for the NO-group the score slightly elevated to 36.7 ± 16.4 producing similar results for both groups (p = 0.81). Conclusion A temporary change of country and school at first results in a rise in anxiety levels in about one third of participants. However, after an extended stay it falls to normal levels.

Medications for Sleep Schedule Adjustments in Athletes

Context:

Sleep schedule adjustments are common requirements of modern-day athletes. Many nonpharmacologic and pharmacologic strategies exist to facilitate circadian rhythm shifts to maximize alertness and performance during competition. This review summarizes the evidence for commonly used pharmacologic agents and presents recommendations for the sports medicine provider.

Evidence Acquisition:

MEDLINE searches were performed using the following keywords: sleep aids, circadian rhythm adjustment, athletes and sleep, caffeine and sports, melatonin and athletes, and sleep aids and sports. Pertinent articles were extracted and discussed.

Study Design:

Clinical review.

Level of Evidence:

Level 2.

Results:

There are very few available studies investigating pharmacologic sleep aids in athletes. Data from studies involving shift workers and airline personnel are more abundant and were used to formulate recommendations and conclusions.

Conclusion:

Melatonin, caffeine, and nonbenzodiazepine sleep aids have a role in facilitating sleep schedule changes in athletes and maximizing sports performance through sleep enhancement.

Captain Haddock's health issues in the adventures of Tintin. Comparison with Tintin's health issues

BACKGROUND

We currently lack a comprehensive and systematic description of the challenges and health impairments (HI) faced by Captain Haddock over the course of the 15 Tintin adventures in which he appears. Their respective HIs have yet to be compared.

METHODS

We evaluated the spectrum of HIs that Haddock sustains in these 15 adventures as well as their causes, consequences, and their relationship to alcohol or travel beyond Belgium. We diagnosed Haddock's HIs according to descriptive terms in the text. We then classified HIs as traumatic and non-traumatic, and distinguished between intentional and unintentional events. We compared the depiction of HIs involving Haddock and Tintin.

RESULTS

We found 225 events leading to 249 HIs, two hospitalisations, and three medical consultations. There was a median of 19 HIs/adventure (range 4-27/adventure) with 193 cases of trauma (77.5%) and 56 non-traumatic problems (22.5%). There were 109 cases of concussion (43% of all HI, 56% of all trauma). We encountered 12 burns including ten relating to Haddock's tobacco habit. The most common forms of non-traumatic problems were linked to alcoholism (57%), and specifically drunkenness (37%). Haddock is diagnosed with cirrhosis early in Tintin's adventures. He significantly decreases his consumption of alcohol after he meets Tintin (58.3% of HI before vs 10.7% of HI after; P<0.001; OR 5.4) but not his use of tobacco. He is also susceptible to certain travel-related illnesses such as mosquito bites, ear discomfort, exposure to exotic animals, and perhaps jet lag. Overall, Haddock presents as many HIs (249 vs 244) and trauma (190 vs 193) as Tintin, but suffers significantly more HIs/adventure than Tintin (median 19 vs 8, P=0.03), and the traumas are significantly less severe, LoCs accounting for 23% of Tintin's traumatic HIs vs 2.5% for Haddock (P<0.001; OR: 5.1).

CONCLUSION

Traumatic HIs and concussion are the leading cause of HIs for Tintin and Haddock but are clearly less severe for Haddock. Haddock evolves from alcoholic sea Captain to a country gent who is less addicted to alcohol than he is to tobacco.

Medical Problems during Participation of Medical Congress - A Long Trip to Val D'Isere from Korea

Since the 3rd WIN meeting in 1982 more than 500 participants join the meeting in Val D'Isere every year [1]. One of our authors has attended the meeting more than 10 times. He experienced many physical illnesses while travelling from South Korea to Val D'Isere in France, which is located in the Alps mountain near the border between France and Italy. In order to get there, it is necessary to take airplane, train, and/or bus with a heavy suitcase. During the trip which usually takes more than 15 hours, he experienced headache, gastrointestinal trouble, sleep disturbance and other additional physical illnesses. Therefore, we reviewed the itinerary to Val D'Isere and presented physical illnesses which occurred during a long trip for an academic activity by specialized professionals such as university hospital professors. In addition, we discussed the mechanism of such illnesses and offered possible solutions including medical treatment.

Use of Drosophila in the investigation of sleep disorders

Genetic underpinnings for sleep disorders in humans remain poorly identified, investigated and understood. This is due to the inherent complexity of sleep and a disruption of normal sleep parameters in a number of neurological disorders. On the other hand, there have been steady and remarkable developments in the investigation of sleep using model organisms such as Drosophila. These studies have illuminated conserved genetic pathways, neural circuits and intra-cellular signaling modules in the regulation of sleep. Additionally, work in model systems is beginning to clarify the role of the circadian clock and basal sleep need in this process. There have also been initial efforts to directly model sleep disorders in flies in a few instances where a genetic basis has been suspected. Here, we discuss the opportunities and limitations of studying sleep disorders in Drosophila and propose that a greater convergence of basic sleep research in model organisms and human genetics should catalyze better understanding of sleep disorders and generate viable therapeutic options.

Buying time: a rationale for examining the use of circadian rhythm and sleep interventions to delay progression of mild cognitive impairment to Alzheimer's disease

As of 2010, the worldwide economic impact of dementia was estimated at $604 billion USD; and without discovery of a cure or effective interventions to delay disease progression, dementia's annual global economic impact is expected to surpass $1 trillion USD as early as 2030. Alzheimer's disease (AD) is the leading cause of dementia accounting for over 75% of all cases. Toxic accumulation of amyloid beta (Aβ), either by overproduction or some clearance failure, is thought to be an underlying mechanism of the neuronal cell death characteristic of AD-though this amyloid hypothesis has been increasingly challenged in recent years. A compelling alternative hypothesis points to chronic neuroinflammation as a common root in late-life degenerative diseases including AD. Apolipoprotein-E (APOE) genotype is the strongest genetic risk factor for AD: APOE-ε4 is proinflammatory and individuals with this genotype accumulate more Aβ, are at high risk of developing AD, and almost half of all AD patients have at least one ε4 allele. Recent studies suggest a bidirectional relationship exists between sleep and AD pathology. Sleep may play an important role in Aβ clearance, and getting good quality sleep vs. poor quality sleep might reduce the AD risk associated with neuroinflammation and the ε4 allele. Taken together, these findings are particularly important given the sleep disruptions commonly associated with AD and the increased burden disrupted sleep poses for AD caregivers. The current review aims to: (1) identify individuals at high risk for dementia who may benefit most from sleep interventions; (2) explore the role poor sleep quality plays in exacerbating AD type dementia; (3) examine the science of sleep interventions to date; and (4) provide a road map in pursuit of comprehensive sleep interventions, specifically targeted to promote cognitive function and delay progression of dementia.

Adrenal Clocks and the Role of Adrenal Hormones in the Regulation of Circadian Physiology

The mammalian circadian timing system consists of a master pacemaker in the suprachiasmatic nucleus (SCN) and subordinate clocks that disseminate time information to various central and peripheral tissues. While the function of the SCN in circadian rhythm regulation has been extensively studied, we still have limited understanding of how peripheral tissue clock function contributes to the regulation of physiological processes. The adrenal gland plays a special role in this context as adrenal hormones show strong circadian secretion rhythms affecting downstream physiological processes. At the same time, they have been shown to affect clock gene expression in various other tissues, thus mediating systemic entrainment to external zeitgebers and promoting internal circadian alignment. In this review, we discuss the function of circadian clocks in the adrenal gland, how they are reset by the SCN and may further relay time-of-day information to other tissues. Focusing on glucocorticoids, we conclude by outlining the impact of adrenal rhythm disruption on neuropsychiatric, metabolic, immune, and malignant disorders.