Category: Insomnia

 Nighttime visits to the bathroom are generally associated with being pregnant or having an enlarged prostate, but the problem can affect youngsters, too. A new study sheds light on why some children may need to urinate more often during the rest cycle. Danish researchers have found that sleep deprivation causes healthy children, between the ages of eight and twelve, to urinate significantly more frequently, excrete more sodium in their urine, have altered regulation of the hormones important for excretion, and have higher blood pressure and heart rates.

The study appears in the American Journal of Physiology — Renal Physiology, published by the American Physiological Society.

Methodology

Twenty healthy children (ten boys and ten girls) were enrolled in the study. The children underwent two consecutive 24-hour stays at the hospital. The first 24-hour period was used to register baseline values including urine data, blood pressure and heart rate, and other physiological measures. The second 24-hour period was used to register these values during and following sleep deprivation. The information was subsequently compared with everyday life records submitted by the parents.

On both evenings the children were required to be in a supine position in bed in a dimly lit room at 8:00 p.m. Physical activity, food and fluid intake were not allowed between this time and 7:00 a.m. In addition, on the second night, the children were kept awake as long as possible throughout the night, if they were willing, by telling and listening to stories, doing small tasks such as word and memory games, or making crafts. Daytime "catch up" sleep was not allowed.

Results Sleep deprivation had a dramatic effect on nighttime urine excretion, with an average increase of 68 percent among the participants. The amount of sodium in the urine from the sleep-deprived night was almost a third greater than it was during the normal-sleep night. The levels of hormones associated with water and sodium excretion had numerous differences after the sleep-deprivation, and blood pressure and heart rate were significantly higher. The findings were similar between boys and girls.

Importance of the Findings

The study finds that sleep deprivation leads to numerous physiologic differences in children that, ultimately, result in greatly increased urine output and significantly higher sodium excretion. The authors speculate that the reason for these differences could be the result of changes in the regulations of the hormones responsible for setting water and sodium output in the kidney, which also affect heart rate and blood pressure.

Finding ways to address these factors could stem nighttime urine production, which in turn could potentially help sleep disruption and bed-wetting in youngsters, according to the authors. They add, "The close relationship between the regulation of the sleep-wake cycle, blood pressure, and nocturnal urine output points toward sleep induction or blood pressure lowering treatment as possible new concepts in enuresis [bed-wetting] research and treatment."

The study was conducted by B. Mahler, K. Kamperis, M. Schroeder, J. Frokiaer, J. C. Djurhuus, and S. Rittig, all of Aarhus University Hospital in Denmark.

Caffeinated drinks such as coffee and soda are the pick-me-ups of choice for many people, but too much caffeine can cause nervousness and sleep problems.

Caffeine Zone, a software app developed by Penn State researchers, can help people determine when caffeine may give them a mental boost and when it could hurt their sleep patterns. The software takes information on caffeine use and integrates it with information on the effects of caffeine to produce a graph of how the caffeine will affect the users over time.

"Many people don't understand how caffeine levels in their bloodstream go up and how they go down," said Frank Ritter, professor of information sciences and technology, psychology, and computer science and engineering. "It's important to understand the effect that caffeine can have at these various levels."

Ritter, who worked with Kuo-Chuan (Martin) Yeh, assistant professor of computer science and engineering, said that if a person drinks a cup of coffee rapidly, they will experience a spike in mental alertness, but enough of the drug can linger in the bloodstream to cause sleep problems hours later.

The researchers used peer-reviewed studies as input data to determine that caffeine drinkers with between 200 and 400 milligrams of caffeine in their bloodstream are in an optimal mental alertness zone. For sleep, the researchers set a lower threshold of 100 milligrams. Drinkers may have sleep problems if they remain above this.

The researchers, who reported their findings at the 2011 Augmented Cognition International Conference, said people who drink too much caffeine, too quickly, may face other problems. A spike of caffeine above the optimal level can cause nausea and nervousness.

Maintaining proper caffeine balance is important for many workers. For example, sailors on submarines must carefully watch their sleep patterns because their sleeping and waking patterns vary each day, Ritter said.

"If they, and others who drink coffee to stay awake, drink too much coffee on one shift, they may have trouble sleeping," said Ritter. "So, the next day, they'll drink even more coffee and have even more trouble sleeping."

To plot caffeine's effect with the app, drinkers type in information about how much caffeine they drank, or plan to drink, and when they plan to have a caffeinated beverage. They also can add how fast they drink the beverage.

The app can also help people determine when to modify their caffeine habits, so that they might choose to drink a decaffeinated beverage, or mix a blend of caffeinated and decaffeinated coffees.

The app is available on iTunes for free with advertisements and for purchase without ads. It works only on Apple devices — the iPhone, iPod Touch and iPad.

The Office of Naval Research supported this work.

 Whether or not you know any high school students that actually get nine hours of sleep each night, that's what U.S. federal guidelines currently prescribe.

A new Brigham Young University study found that 16- to 18-year-olds perform better academically when they shave about two hours off that recommendation.

"We're not talking about sleep deprivation," says study author Eric Eide. "The data simply says that seven hours is optimal at that age."

The new study by Eide and fellow BYU economics professor Mark Showalter is the first in a series of studies where they examine sleep and its impact on our health and education. Surprisingly, the current federal guidelines are based on studies where teens were simply told to keep sleeping until they felt satisfied.

"If you used that same approach for a guideline on how much people should eat, you would put them in a well-stocked pantry and just watch how much they ate until they felt satisfied," Showalter said. "Somehow that doesn't seem right."

In the new study, the BYU researchers tried to connect sleep to a measure of performance or productivity. Analyzing data from a representative sample of 1,724 primary and secondary school students across the country, they found a strong relationship between the amount of sleep youths got and how they fared on standardized tests.

But more sleep isn't always better. As they report in the Eastern Economics Journal, the right amount of sleep decreases with age:

• The optimal for 10-year-olds is 9 — 9.5 hours
• The optimal for 12-year-olds is 8 — 8.5 hours
• The optimal for 16-year-olds is 7 hours

"We don't look at it just from a 'your kid might be sleeping too much' perspective," Eide said. "From the other end, if a kid is only getting 5.5 hours of sleep a night because he's overscheduled, he would perform better if he got 90 minutes more each night."

The size of the effect on test scores depends on a number of factors, but an 80-minute shift toward the optimum is comparable to the child's parents completing about one more year of schooling.

"Most of our students at BYU, especially those that took early-morning seminary classes in high school, are going to realize that 9 hours of sleep isn't what the top students do," Showalter said.

 Scientific research has shed new light on dissociative symptoms and dissociative identity disorder, formerly known as multiple personality disorder. This condition seems to arise most often when a vulnerable person meets a therapist with a suggestive line of questioning or encounters sensationalized media portrayals of dissociation. Research shows that people with rich fantasy lives may be especially susceptible to such influences.

A new article published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, suggests a mundane but surprising reason why some people might be vulnerable to dissociation: sleep problems.

The pop psychology belief is that patients develop multiple personalities to cope with traumatic experiences in their past, especially child sexual abuse. But this assumption isn't supported by scientific evidence, says Steven Jay Lynn of Binghamton University, who cowrote the new paper with Scott O. Lilienfeld of Emory University and Harald Merckelbach, Timo Giesbrecht, and Dalena van der Kloet of Maastricht University in the Netherlands. Many people with dissociative disorders do say they were abused as children, but that doesn't mean abuse caused their condition.

A more likely explanation, Lynn says, is that dissociative identity disorder arises from a combination of cues, from therapists and from visions of multiple personalities in the media. A vulnerable person can be guided by therapists who use hypnosis or ask leading questions, like "Is there another part of you who I haven't spoken with?" Through that kind of suggestive therapy technique, people might start to think their mood changes, confusion, and impulsive actions happen because they have multiple selves living in the same body — when they begin psychotherapy with more run-of-the-mill psychological problems.

Lynn and his colleagues' research further suggests that sleep problems may be one reason why some people are more vulnerable to dissociation and dissociative disorders. In one study, Lynn's colleagues kept 25 healthy volunteers from sleeping for one night and found they had many more dissociative experiences. This could help to explain a connection between trauma and dissociation, as traumatic memories can disturb sleep. Poor sleep can also impair memory and increase suggestibility, potentially increasing the impact of leading interventions. "We're not arguing that this is a complete or final explanation," Lynn says. "We just hope the word will get out and other investigators will start looking at this possibility."

"We want to educate the many therapists who may be strongly influenced by the traditional model of dissociation not only to think otherwise but to practice otherwise," Lynn says. Therapists should "be scrupulous in avoiding suggestive approaches — not only with people who may be particularly vulnerable to those procedures, but with people in general who seek help." Also, he cautions, "if your therapist is trying to convince you that you have multiple personalities, you should find a new therapist."

 It's been said that timing is everything, and that may be particularly true when it comes to the ability to fight off disease. New research published in the February issue of the journal Immunity shows that the success of host immune defense depends in part on an organism's "body clock." The study may lead to therapeutic strategies designed to optimize the immune response and to protect patients at the time when they are most vulnerable.

Many organisms have evolved an endogenous timing system called a circadian clock that regulates a wide variety of metabolic activities over a twenty-four hour cycle. "It is becoming increasingly evident that disruption of daily rhythms, such as from sleep deprivation, affects the immune response," explains senior study author, Dr. Erol Fikrig from Yale University School of Medicine. "In our study, we were interested in investigating whether the ability of the immune system to detect a pathogen is under circadian control and whether there are timing-associated consequences for the subsequent immune response."

Dr. Fikrig and colleagues examined the expression and function of Toll-like receptor 9 (TLR9), an immune system protein that can sense bacterial and viral DNA. The researchers demonstrated that the circadian clock controlled TLR9 expression and function and that mice immunized when TLR9 was most responsive exhibited an enhanced immune response. Importantly, in a mouse model of sepsis, disease severity was dependent on the timing of sepsis induction, which directly correlated with cyclical changes in TLR9. The authors suggest that this observation may be clinically significant as septic human patients are known to be at increased risk of mortality between 2 and 6 am.

"These findings not only unveil a novel, direct molecular link between circadian rhythms and the immune system, but also open a new paradigm in the biology of the overall immune response with important implications for the prevention and treatment of disease," concludes Dr. Fikrig. "Furthermore, patients in the ICU often have disturbed sleep patterns, due to noise, nocturnal light exposure and medications; it will be important to investigate how these factors influence TLR9 expression levels and immune responses."

Researchers at the Perelman School of Medicine at the University of Pennsylvania have put sleeplessness on the map — literally. The research team, analyzing nationwide data collected by the Centers for Disease Control and Prevention (CDC), has produced the first state-by-state sleep maps for the United States, revealing that residents of Southern states suffer from the most sleep disturbances and daytime fatigue, while residents on the West Coast report the least amount of problems. The results are published online in the Journal of Clinical Sleep Medicine.

"Sleep disturbance is a major public health concern. However, geographic dispersion of sleep problems, and the factors that may play a role in why some states or regions get better sleep, have been largely unexplored," said Michael A. Grandner, PhD, research associate at the Center for Sleep and Circadian Neurobiology at Penn and lead author of the study. "Our study generated the first sleep maps for the U.S. that include data on sleep disturbance and daytime fatigue across most of the country."

The findings suggest that, in general, those in the South are most likely to report sleep disturbance and daytime fatigue, and those in the West are least likely. Of the states where data was collected, Oklahoma, Arkansas, Mississippi, Alabama, and West Virginia ranked in the highest bracket for each category. The researchers note that this finding is consistent with other geographic studies, showing that many of the states that report worse sleep and fatigue problems are the same states that tend to report higher prevalence of other conditions, such as obesity, and that the pattern differed slightly between men and women.

The new study evaluated state-based prevalence of self-reported sleep disturbance and daytime fatigue across 36 U.S. states/ territories using data from 157,319 people who took part in the 2006 Behavioral Risk Factor Surveillance System (BRFSS). The BRFSS is an annual, state-based, random digit-dialed telephone interview survey of adults aged 18 years and older from all over the U.S., conducted by the CDC. It is the world's largest telephone survey, designed to monitor health-related behaviors in the general population.

The prevalence estimates for each state/territory were based on weighted figures derived from the census, so that every age, sex, and race/ethnicity combination was included relative to how often they were reported in the U.S. census — helping to ensure that the data accurately reflect the general population. Overall, a pattern was found where some states reported higher prevalence of sleep disturbance and/or daytime fatigue, and that these differences could not be completely accounted for when adjusted for demographics (age, sex, race/ethnicity), socioeconomics (education, income, employment), mental health (depression, general mental health), physical health (general health, overall physical health, healthcare access, obesity), and substance use (alcohol, smoking).

To better understand the sleep patterns, the researchers examined a number of underlying possibilities, such as demographics, obesity, health, and even weather and sunlight patterns in the different states. They determined that regional differences in mental health, race/ethnicity, and access to medical care were the strongest factors that explain these differences.

"The take-home message from this study is that different regions of the country sleep better than others," said Dr. Grandner. "We should begin to use this data to track patterns of poor sleep and try to understand why these patterns occur. Sleep is such an important part of overall health, we need to do everything we can to help give a good night's sleep to those in the highest-risk regions."

Dr. Grandner and his colleagues note that targeted public health campaigns about healthy sleep patterns in states/regions that are most prone to sleep problems and increased screening programs for sleeplessness symptoms may help better guide individuals with sleep issues to medical care.

On the surface, it's simple: when night falls, our bodies get sleepy. But behind the scenes, a series of complex molecular events, controlled by our genes, is hard at work to make us groggy. Now, research suggests that a newly identified gene known as insomniac may play a role in keeping us asleep. By cloning and testing this gene in fruit flies, Rockefeller University researchers say they have discovered an entirely new mechanism by which sleep is regulated.

Nicholas Stavropoulos, a postdoc, and Michael W. Young, Richard and Jeanne Fisher Professor and head of the Laboratory of Genetics, conducted a genetic screen of approximately 21,000 fruit flies. Using a device that employs infrared beams to detect when the flies nod off, they discovered that mutations in the insomniac gene were associated with a dramatic reduction in sleep. While a typical fruit fly sleeps for average of 927 minutes a day, insomniac flies snoozed for just 317. The mutant flies also slept for shorter periods of time, and slept and woke more frequently.

"The results showed a dramatic loss of both the duration of the flies' sleep and their ability to remain asleep after they dozed off," says Stavropoulos. "But what's especially interesting is that the insomniac gene may function through homeostatic mechanisms. These are distinct from the well-studied circadian clock pathways linked to sleep, and have an effect on the body regardless of the time of day."

The scientists believe that insomniac works by engaging a specific series of protein degradation pathways in neurons through a complex known as Cul3. If correct, this would be the first time that a protein degradation pathway, in which specific proteins are eliminated within a cell, has been linked to sleep.

The researchers also examined the link between sleep and lifespan, finding that flies with mutations to the insomniac gene lived only about two-thirds as long as unaltered flies (other studies have suggested similar effects in both flies and rats that are deprived of sleep). But when the scientists eliminated insomniac only in neurons — allowing it to remain in the rest of the flies' bodies — this disparity was eliminated; the resulting animals slept poorly but lived just as long.

"This suggests that reduced sleep can be 'uncoupled' from reduced lifespan, supporting the idea that some disruptions of sleep do not affect overall health, at least as far as lifespan is concerned," Stavropoulos says.

Although flies and humans would appear to have little in common when it comes to lifestyle, scientists say that the mechanisms of sleep and wakefulness are likely to be quite similar.

"Sleep is a fundamental behavior in all animals, and it is poorly understood from a scientific standpoint," says Stavropoulos. "This work gives us several new clues about how sleep is controlled at the molecular level, and could prove useful in understanding and treating sleep disorders."

People are relying on sleeping pills more than ever to get a good night's rest, but a new study by Scripps Clinic researchers links the medications to a 4.6 times higher risk of death and a significant increase in cancer cases among regular pill users.

The results, published February 27 by the open-access online journal BMJ Open, cast a shadow over a growing segment of the pharmaceutical industry that expanded by 23 percent in the United States from 2006 to 2010 and generated about $2 billion in annual sales.

The possible health hazards

"What our study shows is that sleeping pills are hazardous to your health and might cause death by contributing to the occurrence of cancer, heart disease and other ailments," said author Daniel F. Kripke, MD, of the Viterbi Family Sleep Center at Scripps Health in San Diego.

The research is the first to show that eight of the most commonly used hypnotic drugs were associated with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (known by the brand name Ambien) and temazepam (also known as Restoril), Dr. Kripke said. Those drugs had been thought to be safer than older hypnotics because of their shorter duration of action.

Study participants who took sleeping pills were matched with control patients of similar ages, gender and health who received no hypnotics in order to eliminate the possibility that other factors led to the results.

"We tried every practical strategy to make these associations go away, thinking that they could be due to use by people with more health problems, but no matter what we did the associations with higher mortality held," said co-author Robert D. Langer, MD, MPH, of the Jackson Hole Center for Preventive Medicine in Jackson, Wyoming.

Even among patients who were prescribed 1 to 18 sleeping pills per year, the risk of death was 3.6 times higher than among similar participants who did not take the medica-tions. The study looked at patients aged 18 years and older, and found the increased risk in all age groups.

Sleeping pills and cancer

Rates of new cancers were 35 percent higher among patients who were prescribed at least 132 hypnotic doses a year as compared with those who did not take the drugs.

Using data stored in an electronic medical record that has been in place for more than a decade, the researchers obtained information on almost 40,000 patients cared for by a large integrated health system in the northeastern United States.

The study included 10,531 sleeping pill users who were prescribed the medications for an average of 2.5 years and 23,674 control participants who were not prescribed the drugs. Information came from outpatient clinic visits conducted between Jan. 1, 2002, and Sept. 30, 2006.

"It is important to note that our results are based on observational data, so even though we did everything we could to ensure their validity, it's still possible that other factors explain the associations," said co-author Lawrence E. Kline, DO, who is medical director of the Viterbi Family Sleep Center. "We hope our work will spur additional research in this area using information from other populations."

Funding for the study came from the Scripps Health Foundation and other philanthropic sources.

Alternatives to medication

The BMJ Open report should prompt physicians to consider alternatives to hypnotic medications, Dr. Kline said.

Clinicians at the Viterbi Family Sleep Center focus on cognitive therapy that teaches patients to better understand the nature of sleep. For example, some people suffering from insomnia might require less than the eight hours of sleep commonly recommended for each night.

Patients also can benefit from practicing good sleeping habits and relaxation, as well as taking advantage of the body's natural clock, which is driven by the rising and setting of the sun, Dr. Kline said. "Understanding how to use the circadian rhythm is a very powerful tool that doesn't require a prescription," he said.

When insomnia results from emotional problems such as depression, doctors should treat the psychological disorder rather than prescribe sleeping pills that could prove to be harmful, Dr. Kripke said.

Yale University researchers have discovered a key cellular mechanism that may help the brain control how much we eat, what we weigh, and how much energy we have.

The findings, published in the Feb. 28 issue of the Journal of Neuroscience, describe the regulation of a family of cells that project throughout the nervous system and originate in an area of the brain call the hypothalamus, which has been long known to control energy balances.

Scientists and pharmaceutical companies are closely investigating the role of melanin-concentrating hormone (MCH) neurons in controlling food intake and energy. Previous studies have shown that MCH makes lab animals eat more, sleep more, and have less energy. In contrast, other hypothalamic neurons use the thyrotropin-releasing hormone (TRH) as a neurotransmitter, and these neurons reduce food intake and body weight, and increase physical activity.

The Yale study of brains of mice shows that the two systems appear to act in direct opposition, to help the organism keep these crucial functions in balance.

Although TRH is normally an excitatory neurotransmitter, the Yale study shows that in mice TRH inhibits MCH cells by increasing inhibitory synaptic input. In contrast, TRH had little effect on other types of neurons also involved in energy regulation.

"That these two types of neurons interact at the synaptic level gives us clues as to how the brain controls the amount of food we eat, and how much we sleep," said Anthony van den Pol, senior author and professor of neurosurgery at Yale School of Medicine.

The co-author of the paper is Xiaobing Zhang of Yale.

The people we trust to take us or our loved ones from place to place struggle with sleep, according to the National Sleep Foundation's (NSF) 2012 Sleep in America^® poll. It is the first poll to ask transportation professionals, including pilots, train operators,* truck, bus, taxi and limo drivers about their sleep habits and work performance.

Pilots and train operators are most likely to report sleep-related job performance and safety problems

The results of the poll are striking. About one-fourth of train operators (26%) and pilots (23%) admit that sleepiness has affected their job performance at least once a week, compared to about one in six non-transportation workers (17%).

Perhaps more disturbingly, a significant number say that sleepiness has caused safety problems on the job. One in five pilots (20%) admit that they have made a serious error and one in six train operators (18%) and truck drivers (14%) say that they have had a "near miss" due to sleepiness.

Sleepiness has also played a role in car accidents commuting to and from work. Pilots and train operators are significantly more likely than non-transportation workers (6% each, compared to 1%) to say that they have been involved in a car accident due to sleepiness while commuting.

"Driving home from work after a long shift is associated with crashes due to sleepiness," says Dr. Sanjay Patel, a sleep researcher at Brigham and Women's Hospital and Harvard Medical School. "We should all be concerned that pilots and train operators report car crashes due to sleepiness at a rate that is six times greater than that of other workers."

Train operators and pilots report most sleep dissatisfaction

Among all workers surveyed, train operators and pilots report the most work day sleep dissatisfaction. Almost two-thirds of train operators (57%) and one-half of pilots (50%) say they rarely or never get a good night's sleep on work nights, compared to 44% of truck drivers and 42% of non-transportation workers. Bus, taxi, and limo drivers report the best work day sleep satisfaction, with about one-third (29%) saying they rarely or never get a good night's sleep on work nights.

"The margin of error in these professions is extremely small. Transportation professionals need to manage sleep to perform at their best," says David Cloud, CEO of the National Sleep Foundation. "As individuals and employers, we need to know more about how sleep improves performance."

Sleepiness is common for all workers

Roughly one in ten Americans say they are likely to fall asleep at an inappropriate time and place, such as during a meeting or while driving. The poll included a validated assessment tool used by doctors to determine whether a person is "sleepy." Anyone who suffers from excessive sleepiness should seek professional help to identify underlying conditions. This study finds that 11% of pilots, train operators, bus, taxi, and limo drivers and 8% of truck drivers as well as 7% of non-transportation workers are "sleepy."

"We found that although pilots are especially focused on obtaining adequate sleep, one in ten can still be classified as 'sleepy.' This is not acceptable. Who among us wants to take a one in ten chance of flying on a plane with a sleepy pilot?" says CPT Edward Edens, PhD of the Walter Reed Army Institute of Research.

A sleepy transportation worker is far more prone to mistakes: sleepy transportation workers report job performance problems about three times more often and report averaging about 45 minutes less sleep per night than their non-sleepy peers.

Significant number of transportation workers say their schedules do not allow enough time for sleep

Many transportation workers cite their schedule as a major contributor to sleep problems. Almost one-half of train operators (44%) and more than one-third of pilots (37%) report that their current work schedule does not allow adequate time for sleep, compared to about one-fourth of non-transportation workers and truck drivers (27% each) and one-fifth of bus, taxi and limo drivers (20%).

In general, transportation professionals work more varied shifts than other workers, which may play a role in their sleep problems. Only 6% of pilots and 47% of train operators say they work the same work schedule each day, compared to 76% of non-transportation workers.

Time off between shifts may play a role in transportation workers' sleepiness. Non-transportation workers report having an average of 14.2 hours off between shifts, compared to 12.9 hours for pilots; 12.5 for train operators; 12.1 for truck drivers; and 11.2 hours for bus, taxi, and limo drivers. If given one more hour off between work shifts, over one-half of pilots (56%) and train operators (54%) report that they would use that hour for sleep.

Long commutes cut into transportation workers' already shortened time between shifts. Pilots report the longest commutes with 37% saying it takes more than an hour to get to work from home. Pilots and train operators have the highest average commute time of 45.5 minutes and 31 minutes, respectively, compared to a 23.8 minute average for non-transportation workers. Other research has consistently found that longer commute times have been associated with shorter individual sleep times.

"Transportation workers experience considerable variability in the days they work, the times they work, and the amount of time off between shifts. This makes it difficult for such workers to maintain regular sleep/wake schedules, which can, in turn, make it difficult for these workers to maintain alertness on the job. Employers should put more effort into designing work/rest schedules that facilitate sleep and minimize workers exposure to irregular, variable schedule changes," says Patrick Sherry, PhD, a sleep researcher and professor from theUniversity of Denver Intermodal Transportation Institute.

Pilots and train operators nap twice as frequently

The poll shows that transportation professionals are taking more naps than other workers. More than one-half of pilots (58%) and train operators (56%) take at least one nap on work days, compared to about one-fourth of non-transportation workers (27%). About one in five pilots (20%), bus, taxi and limo drivers (20%), truck drivers (16%) and train operators (16%) say they take 3-5 naps during the work week. Among those who report napping on work days, one-half of pilots (50%), almost one-half of truck drivers (42%), one-third of train operators (33%) and nearly one-fourth of bus, taxi and limo drivers (24%) say they actually napped during work hours in the past two weeks, compared to about one in five non-transportation workers (19%).

"Transportation workers have challenging schedules that compete with the natural need for sleep. While I'm impressed that transportation professionals nap when they are off duty, we need to better understand how to use naps to reduce sleep deprivation and overcome scheduling issues," says Thomas Balkin, PhD, a sleep researcher from the Walter Reed Army Institute of Research.