When you’re a new parent - or heck, even a veteran one – nothing is worse than a child who won’t sleep. The ensuing sleep deprivation (for the parent) can feel soul-crushing, and there are moments when one would do anything for just a few hours of uninterrupted nighttime quiet. (If only babies took bribes.)
Now, research is showing that a baby’s sleep problems might lead to something other than bleary-eyed, grumpy parents: In a study of 359 children, those who had trouble sleeping as an infant appeared to have a greater risk of developing a sleep disorder when they were older. As reported on Well today:
The new research is a rare look at a problem that many parents and even pediatricians sometimes fail to notice. The study, which looked at children ages 6 months to 3 years, found that sleep problems were common in this age group. But parents did not always perceive red flags like loud and frequent snoring — which can be a risk factor for obstructive sleep apnea, a potentially serious breathing disorder — as problems that warranted mentioning to their pediatricians.
The findings also challenged a widespread notion that children who have sleep troubles early on tend to outgrow them. In the study, children who had one or more sleep problems at any point in early childhood were three to five times as likely to have a sleep problem later on.
The research, which appears in Pediatrics, shouldn’t panic parents – but instead serve as a reminder of the importance of looking for warning signs of a more serious sleep problem (listed here as things like frequent loud snoring, night terrors and taking a long time to fall asleep) and talking to one’s pediatrician. Also from Well:
[Study author Kelly Byars, PsyD] said the best way parents can distinguish a true sleep disorder from a phase is to be on the lookout for problems that persist over time, and to raise any concerns with a pediatrician. “If a child has problems across two consecutive well-child visits” — at the 6-month checkup, for example, then again at 12 months, “then that is likely an indicator that this is a problem that should be addressed, as opposed to saying that it’s a problem the child will grow out of,” he said.
People who have trouble sleeping or staying asleep may catch more Zzz’s and feel more alert during the day by working out 150 minutes or more per week, according to findings published in the December issue of Mental Health and Physical Activity.
The study examined the relationship between accelerometer-measured physical activity and sleep among a nationally representative sample of more than 2,600 men and women ages 18-85. According to a university release researchers found that adults who met the national guidelines for physical activity, which is at least 150 minutes of moderate to vigorous activity a week, experienced a significant improvement in sleep quality:
After controlling for age, BMI (Body Mass Index), health status, smoking status, and depression, the relative risk of often feeling overly sleepy during the day compared to never feeling overly sleepy during the day decreased by 65 percent for participants meeting physical activity guidelines.
Similar results were also found for having leg cramps while sleeping (68 percent less likely) and having difficulty concentrating when tired (45 percent decrease).
The findings add to the growing body of research suggesting physical activity can help improve quality of sleep, vitality and mood.
Women who have trouble sleeping may have a higher risk of developing fibromyalgia, according to findings published online this week in Arthritis & Rheumatism.
In the study (.pdf), Norwegian researchers recruited 12,350 women aged 20 and older and followed them for a 10-year period. Participants were part of a large nationwide health survey that involved completing questionnaires and physical exams first between 1984 and 1986 and again between 1995 and 1997. None of the volunteers had chronic musculoskeletal pain upon enrolling in the study. Medpage Today reports:
A total of 327 women reported having been given a diagnosis of fibromyalgia at follow-up, which represented an incidence proportion of 2.6%.
Women ages 20 to 44 had an incidence proportion of 3.2%; the incidence proportion for those 45 and older was 1.7%.
In analyses that adjusted for smoking, education, physical exercise, body mass index, and education, the researchers found that women 45 and older who had frequent sleep difficulties had a rate ratio for fibromyalgia of 5.41, while the younger cohort had a rate ratio of 2.98.
[Researchers] then compared the 3,949 women who reported sleep problems of any frequency with the 8,401 who had no sleep disturbances, and found a rate ratio for fibromyalgia of 2.10
[Author Lata Casturi] and colleagues, including coauthor Anita Rao, presently a 10th grader at Dawson High School in Pearland, TX, surveyed 255 teens (108 males and 147 females) in high school to obtain self-reported measures of height and weight (used for BMI calculation) and both weekday and weekend quantity of sleep. Among males, results indicated the average sleep time on weekdays was 6 hours 32 minutes and on weekends 9 hours 10 minutes. Among females, the average weekday sleep time was 6 hours 30 minutes and the average weekend sleep duration was 9 hours 22 minutes. Teen males who slept 7 hours or less on weekdays had an average BMI that was 3.8 percent higher than those who slept more than 7 hours. Likewise, teen females who slept 7 hours or less had a BMI that was 4.7 percent higher than females who got more than 7 hours of sleep per weekday.
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Furthermore, after adjusting for potential cofounders, short sleep duration (<8 hours) was associated with obesity in male teens. A negative correlation also was found between weekday sleep duration and obesity in males, with the fewest hours of weekday sleep associated with the highest BMI. There was no evident correlation between obesity and weekday sleep hours in teen females.
The research follows a 2004 Stanford study of more than 1,000 adults that found that sleep loss leads to higher levels of a hormone that triggers appetite, lower levels of a hormone that tells your body it’s full and an increased body mass index. And while the current study doesn’t establish cause-and-effect, it provides further support for the notion that teens – heck, all of us – should get as much sleep as possible.
Lately, I’ve noticed that my teenage niece has been frequently posting to Facebook at 2 a.m. Her nighttime behavior wasn’t particularly surprising, considering previous research that suggests adolescents are biologically programmed to go to bed later and wake up later. But I grew more concerned about her nocturnal Facebook habits after reading a new study showing that lack of sleep during adolescence could affect synapses needed for communication and inhibit normal development of the brain.
During the study (subscription required), researchers at the University of Wisconsin-Madison completed a series of experiments involving young mice to better understand how alterations to the sleep-wake cycle affected the anatomy of the developing adolescent brain. The experiments involved using a two-photon microscope to indirectly observe brain impulses in three groups of mice: those that were spontaneously awake for eight to 10 hours, others forced to stay awake and some allowed to sleep. Researchers determined being asleep or awake made a difference in the growth and depletion of the connections between nerve cells called synapses. Results showed overall density of dendritic spines, the elongated structures that contain synapses and thus allow brain cells to receive impulses from other brain cells, fell during sleep and rose during spontaneous or forced wakefulness.
Chiara Cirelli, MD, PhD, a co-author of the study commented on the significance of the findings in a university release:
Adolescence is a sensitive period of development during which the brain changes dramatically. There is a massive remodeling of nerve circuits, with many new synapses formed and then eliminated… One possible implication of our study is that if you lose too much sleep during adolescence, especially chronically, there may be lasting consequences in terms of the wiring of the brain.
Disruptions to your circadian rhythm, which guide the body’s internal clock, can result in a host of sleep disorders and have been linked to diabetes. In light of the growing body of research suggesting circadian-rhythm disorders may play a role in a number health problems, researchers are working to better understand the genetic underpinnings of the sleep-wake cycle.
While researchers know that our bodies, as well as simpler organisms, are synchronized by sunlight and can drift out of phase in darkness, the details of how a population of cells synchronizes their biological clocks remains a mystery. But new research from UC San Diego could yield important clues, reports Medgadget:
To remedy the problem, UC San Diego biology professor Jeff Hasty led a team of researchers to develop a model biological system that is simpler than that of an organism. The scientists created a simple circadian system using a model consisting of glowing, blinking E. coli bacteria. Drawing on their knowledge of synthetic biology, microfluidic technology, and computational modelling, the researchers built a microfluidic chip containing chambers with E. coli.
Researchers were able to simulate day and night cycles by modifying the bacteria to glow and blink whenever arabinose, a chemical that triggered the oscillatory clock mechanisms of the bacteria, was flushed through the microfluidic chip. This approach allowed researchers to replicate periodic day-night cycles over a period of only minutes rather than days providing a better understanding of how a population of cells synchronizes its biological clocks. The work is further described in a paper (subscription required) recently published in Science.
In the video above, the right side of the screen shows periodic pulses of arabinose (shown in red) act like day and night cycles to simulate how the blinking bacteria synchronize their biological clocks. On the left, a simulation of bacteria in constant darkness reveals how the blinking bacteria are unable to synchronize their biological clocks. The bottom two graphs illustrate the in-phase and out-of-phase oscillations of the biological clocks.
Americans that show up to work too tired to perform on the job could be costing the nation $63 billion in lost productivity each year, according to findings published in the journal SLEEP.
In the study (subscription required), researchers surveyed 7,428 employees about their sleep habits and work performance as part of the American Insomnia Survey, a research project launched by the World Health Organization and Harvard Medical School in 2008. Results showed 23 percent of participants experienced some form of insomnia, which cost their employers the equivalent of 7.8 days of work in lost productivity each year or roughly $2,280 in salary per person.
Stanford sleep expert Clete Kushida, MD, PhD, commented on the findings in a story published today by CNN:
About one-third of all U.S. adults experience weekly difficulties with nighttime sleep, and an estimated 50 to 70 million people complain of associated daytime impairment, the study notes. And while it’s hard to compare past and present research, insomnia does seem to be on the rise, says Clete Kushida, MD, a neurologist and sleep-medicine specialist at the Stanford University School of Medicine, in Palo Alto, Calif.
“There appears to be more insomnia, given more work and family responsibilities, and more technological improvements and distractions,” says Kushida, who was not involved in the new study. “These result in more stress that can precipitate worsened sleep.”
This study was funded by drug companies Sanofi-Aventis and Merck.
A previous report from the National Sleep Foundation shows that the majority of adults in the United States experience problems sleeping. Americans’ struggle to get some shuteye has fueled a growing industry of products and supplements aimed at encouraging better sleep.
Today, the Los Angeles Times’ Healthy Skeptic column evaluates one such sleep aid, called the NightWave, to determine whether the device lives up to manufacture claims that it calms the mind and induces restful sleep. In the article, Stanford sleep expert Clete Kushida, MD, PhD, offers his perspective on the gadget:
The claims behind the NightWave make some sense, Kushida says. Several well-established sleep treatments – including meditation and guided relaxation with a CD – promote slow, rhythmic breathing. But that’s only one part of the process of falling asleep, he adds. “I don’t know of any evidence that slowing down breathing patterns itself will induce sleep.”
He speculates that the NightWave might help some people fall asleep, but he also thinks there are other, cheaper options. “In my opinion, it’s just a relaxation device,” he says. He believes that anything that calms the mind – even the old counting sheep trick – could work just as well for some people at considerably less cost.
Insufficient sleep has been linked to a host of health problems including heart disease, depression and obesity. To learn more about the importance of sleep, listen to this recent 1:2:1 podcast with Stanford sleep specialist Rafael Pelayo, MD.
Associate professor Steven Howard, MD, is well known for his research on fatigue and sleep deprivation, especially as it relates to health-care professionals. Howard’s previous research has shown the benefit of napping on emergency room doctor and nurses’ performance, the implications of fatigue among clinicians and the potential risks of daytime sleepiness among resident physicians.
Below he discusses how fatigue negatively affects performance, the role cultural beliefs or societal pressures play in increasing the prevalence of sleep deprivation in our country and how organizations and professional societies can promote sleep as a priority among health-care professionals.
What happens, physiologically, when a person’s sleep balance is disturbed?
Individuals have a genetically determined sleep need, which for adults is around eight hours. Most of us get far less than this. If you get less sleep than needed, then you develop what is called a “sleep debt.” The only way to repay a sleep debt is by obtaining adequate sleep. People often don’t repay sleep debts for many reasons including that some believe sleep is just “lost time.” Individuals with a sleep debt will often have impaired performance and negative moods, and they are prone to falling asleep at work and elsewhere.
Two years ago, Stanford sleep researcher Emmanuel Mignot, MD, PhD, made headlines when he showed that narcolepsy is an autoimmune disease, caused when patients’ immune systems kill the neurons that produce the protein hypocretin. The current thinking is that a person is genetically predisposed to the disease, and some environmental factor kicks his or her immune system into action.
Now, Mignot and colleagues have a paper in Annals of Neurology that suggests one such trigger: winter airway infections such as H1N1. In a study involving more than 900 narcolepsy patients in China, the researchers found that a peak in narcolepsy cases occurred five to seven months after a peak in flu/cold or H1N1 infections in the country. These winter infections, the authors wrote, appear to have initiated or reactivated an immune response that leads to narcolepsy.
“We’re much closer to understanding what’s happening in the autoimmune destruction of hypocretin cells,” Mignot told me.
In other findings, the researchers observed no link between H1N1 vaccinations and narcolepsy, which is quite different than what has been seen in Europe. (In Finland, for example, children who received the Pandemrix H1N1 vaccine, which contains two additives to invoke a stronger immune response, faced a 9-fold increased risk of the disease.) China uses a different, more mild vaccine, so clearly more study on narcolepsy and vaccines is needed. But in the meantime:
Mignot said the work suggests that getting vaccinated and avoiding influenza may provide a protective benefit to patients. He said, “It’s very possible that being vaccinated with a mild vaccine [one without additives] blocks you from getting a big infection that could increase your risk of narcolepsy.”
More than 12 million Americans suffer from sleep apena, a common disorder that causes abnormal pauses in breathing during sleep. And this week, UCSF research published in the Journal of the American Medical Association showed that older women with the disorder were twice as likely as their healthy counterparts to develop dementia within 5 years.
Stanford’s Emmanuel Mignot, MD, PhD, is well-known for his work on narcolepsy, but he’s also a leading researcher in Kleine-Levin Syndrome (KLS), an extremely rare, but devastating, disease that affects primarily male adolescents. There is much mystery surrounding KLS, which affects 1,000 people worldwide and causes periods of excessive sleep (up to 20 hours at a time) and altered (at times bizarre) behavior. There is no known treatment.
This weekend, Mignot and a handful of other academic and clinical investigators are gathering at the KLS Foundation’s First International Conference to discuss the disease and latest research. In anticipation of the Bay Area event, which is free and open to the public, I spoke with Mignot about the disorder and his work.
This disease is complex, and its symptoms are unusual. What intrigues you the most about it?
The fact that it is periodic and that people are completely normal [in between] episodes. It is a bit like Dr. Jekyll and Mr. Hyde. Further, the symptoms are fascinating. Many other disorders like depression or bipolar are like this, and there is a feeling we should be able to reverse it for good. It could be a model for understanding these other conditions.
Ask any parent of a newborn baby and they’ll tell you that interrupted sleep is the pits: It can leave you feeling cranky, weary and in desperate search of the nearest Starbucks the next day. But can it also hurt your memory?
Seeking to answer that question, a team of Stanford researchers turned to optogenetics to study the effect of sleep continuity on memory in mice. Using the light-based technique to manipulate brain cells (I explain how in a release), the researchers showed that fragmented sleep caused memory impairment in the animals.
To conclude from the work that humans need a certain amount of uninterrupted sleep in order to preserve memory would be “a bit of a stretch,” co-lead author Luis de Lucea, PhD, recently told me. But the study, which appears online today in the Proceedings of the National Academy of Sciences, is significant for several reasons.
The findings suggest that memory problems experienced by patients with certain disorders – like alcoholism and sleep apnea – may be connected with the fragmented sleep connected with those conditions. And because it demonstrates a new, non-invasive way for researchers to investigate specific aspects of sleep in animal models, the work paves the way for future studies on sleep’s effect on the brain.
Earlier this month, tongues across the country wagged over Miami Heat star LeBron James’ less-than-impressive outing in the NBA Finals. Now, weeks later, results of a new Stanford study are making me wonder: Might James have done better if he had just gotten more sleep?
In a paper appearing in the journal SLEEP, Cheri Mah and colleagues – who comprise one of the only research groups in the country to study the effect of sleep on athletes – looked at whether an increase in total sleep time improved the on-the-court performance of members of Stanford’s men’s basketball team. Their findings? During the period in which they got 10 or more hours of total sleep, the players ran faster sprints and improved their shooting accuracy during practice, and they reported lower levels of fatigue. The research suggests, Mah told me, that sleep is an important factor in reaching peak athletic performance.
Sleep doesn’t have the same focus among athletes and trainers as things like nutrition and physical training, Mah says – but perhaps it should. Since the early 2000s, Mah and colleagues have been investigating sleep extension in other Stanford sports teams, including football, tennis, and swimming, and preliminary findings have mirrored what is seen in this publication: More sleep leads to better performance.
Mah is continuing her work in this area and hopes to soon turn her attention to quality, not just quantity, of athletes’ sleep. She now consults on sleep issues with several Stanford sports teams, as well as some professional hockey, football and basketball teams, and she believes her findings may be applicable to recreational athletes and those at the high school, semi-pro or professional level. (James, are you listening?)
Here’s something that should grab the attention of Major League Baseball teams (including my beloved, offense-challenged San Francisco Giants): A small study presented yesterday at SLEEP 2011 hints that the natural sleep preference of professional baseball players may be affecting their batting averages. After surveying 16 players from seven MLB teams, including the Giants, Martha Jefferson Hospital Sleep Medicine Center researchers found that:
…players who were “morning types” had a higher batting average (.267) than players who were “evening types” (.259) in early games that started before 2 p.m. However, evening types had a higher batting average (.261) than morning types (.252) in mid-day games that started between 2 p.m. and 7:59 p.m. This advantage for evening types persisted and was strongest in late games that began at 8 p.m. or later, when evening types had a .306 batting average and morning types maintained a .252 average.
Lead author Christopher Winter, MD, emphasized that the data was not statistically significant, due to low subject numbers, but the numbers do show a trend and warrant future study. And:
“These results are important as they create an entirely new way to look at athletic talent,” said Winter. “Currently, selecting a player for a game situation usually involves factors such as handedness, rest, and possibly previous success against a certain team. Now, the time of day in which the game is occurring and a player’s chronotype might be a wise factor to take into account.”
As previously reported on Scope, Stanford geneticist Michael Snyder, PhD, and colleagues conducted an unprecedented analysis of Snyder's genome using a newly ...
