Sleep deprivation overview

This link about sleep deprivation is informative and worth a look. It won't tell you how much sleep you need. Given that sleep deprivation is a common problem, getting more sleep may help.

Netflix vs sleep

This article discusses how the CEO of Netflix doesn't worry about competition from streaming services like Amazon or HBO. Instead, the CEO worries about the human need to sleep a third of our lives. Because when we sleep, we aren't able to watch Netflix. What an interesting perspective. As a sleep-deprived species, I worry about the effect of Netflix on sleep duration! I guess the relationship is bidirectional.

Living with children may mean less sleep for women

This article discusses research presented at a the annual meeting of the American Academy of Neurology - I didn't attend this meeting. The article surveyed men and women about sleep duration and level of daytime tiredness. Researchers looked at age, race, education, marital status, number of children in the household, income, body mass index, exercise, employment, and snoring as possible factors linked to sleep deprivation. Results showed that living with children was associated with more sleep deprivation in women, but not with men. Also living with children resulted in women feeling more tired in the daytime. One thing not stated was how old the children are in these households. I would imagine that sleep deprivation and daytime tiredness would increase with younger children.

Sleep deprivation and false convictions

Here is a study that attempted to link sleep deprivation to "false confessions." I don't have access to the entire study, only the summary article referenced above. Researchers studied 88 participants in a research lab, where some were sleep deprived for 24 hours and others slept 8 hours. The researchers had the participants take a series of computerized tests and were told not to press the 'Esc' key as that would delete data. At the end of the study, the participants were asked to sign a statement stating they had pressed the 'Esc' key. Results showed that 50% of the sleep-deprived people vs only 18% of the well-rested people signed the 'false confession.'

I'm not sure this demonstrates that sleep-deprivation leads to more false confessions. It may be that sleep-deprivation causes individuals to pay less attention to what they are reading. Signing something at the end of a research study has far less implications than signing a confession statement where you are being accused of a crime you didn't commit. In the latter instances, adrenaline may offset the affects of any sleep deprivation.

Sleep deprivation and insulin

More research continues to be done on the effects of sleep deprivation on our metabolism. This article summarizes a small study looking at how acute sleep loss impacts insulin sensitivity. Researchers studied healthy, young adults without diabetes. They reduced their sleep time from 9 to 5 hours for five nights in a row - supposedly to simulate how little some may sleep during a workweek. After the 5 short nights, they let the participants sleep 9 hours a night for five more nights. The results showed that the subjects sensitivity to insulin decreased during the 5-hour sleep nights. This means that their bodies had to produce more insulin to keep their blood sugar under control. They didn't develop diabetes, but reduced insulin sensitivity is a precursor to diabetes. The next step will be to assess how less sleep affects older adults and adults with pre-diabetes / diabetes.

Sleep and long distance running

This article isn't just about sleep. It's about a runner who does ultra-marathons - typically 50k or 100k races. This runner broke the unofficial record for completing the Appalachian Trail. He finished the 2189 mile journey in only 46 days - this comes out to be 47.5 miles per day! I've ran a marathon and have done many 3-5 night backpacking trips in the Smoky Mountains, but I can't imagine walking or running 47.5 miles per day. What an amazing feat.

The reason I am blogging about this, though, is because the article mentions how the runner only got 4-5 hours of sleep per night. On the last few days, he only got 1-2 hours per night! So this elite athlete could continue to function at his high level even with very little sleep. This fact is interesting because some studies show that athletes perform better when they get plenty of rest. The article doesn't say how much sleep the runner typically gets when not racing. It may be that he only sleeps 5-6 hours on a regular night - so 4-5 hours of sleep would not be that much deprivation.

Napping, impulsivity, and frustration tolerance

Sleep loss can increase the chances of acting impulsively as well as the ability to handle frustration. And for some people, extra sleep can improve frustration tolerance and decrease impulsive behavior. This article is about research on how planned napping may help. I don't have access to the full article, so I can only discuss what's in this article.

The researchers studied 40 adults, ages 18-50 years old. They had the participants keep a regular sleep schedule for three nights and then they completed a series of computer tasks and answered questions. The participants were then randomized to either have a 60 minute nap or watch a nature video before doing the tasks and answering questions again. The results showed that the participants who napped were less impulsive and had better frustration tolerance.

The article attempts to link the study results to workplace productivity but I don't think the study was designed to evaluate that specifically. However, I could see how better-rested employees may perform better. But that productivity advantage may be offset by an hour nap at work!

Sleep duration in American teens

On the heels of last week's post about new sleep duration recommendations, this post is about an article in the journal Pediatrics about the changes in sleep amounts among teens in the United States from 1991 to 2012. The participants were 270,000 8th, 10th, and 12th graders involved in a larger survey. The researchers asked the participants two questions about sleep duration. One was how often they got less 7 hours or at least 7 hours of sleep. The other question was how often the teen felt they got enough sleep per week.

Epidemiological studies show that almost a third of teens don't get enough sleep. The reasons are not known, but researchers speculate that internet, social media, and increased competitiveness of the college admissions process are contributing. And, in last week's blog, I posted a table that recommends 8-10 hrs per night for 14-17 year olds.

The results of the current study showed that self-reported sleep duration in teens has decreased over the past 20 years. The largest decrease was in 15 year olds. Although the data show that sleep duration declined across all age groups and major socio-demographic subgroups, results showed that female students, racial/ethnic minorities, and students of lower socio-economic status (SES) reported getting at least 7 hours of sleep less often than male subjects, non-Hispanic white subjects, and students of higher SES.

American Pediatric Association "Let Them Sleep" statement

The American Pediatric Association recently released a statement that middle and high school students start school at 8:30 AM or later. Sleep-related research supports the later school start time so that adolescents can get more sleep per night. The recommended amount of sleep for teenagers is 8.5 to 9 hours per night, with the majority of teens not getting close to that. Chronic sleep deprivation has been linked with obesity, diabetes, mental health problems, and reduced academic performance.

The statement goes on to explain that teens lack of sleep is complex and involves homework, extracurricular activities, after-school jobs and use of technology that can keep them up late on week nights. So just delaying school start times may not improve teens' sleep duration if other lifestyle changes are not made. The most obvious one is restricting screen time at night.

Astronauts and sleep

This article discusses a study published in the journal Lancet about the sleep patterns of astronauts in space. Since I don't have access to the Lancet article, I don't have all of the details. The article however states that the astronauts are scheduled to get 8.5 hours per day of sleep. On average, they managed to sleep about 6 hours. And 78% of them used sleeping pills about half of the time.

The article goes on to quote someone from NASA who states that the study demonstrates valuable insights into sleep deprivation experienced by astronauts in space. However, I'm not sure it does, but I am basing this on the article, not the actual study. The article doesn't give me any insight, only leads to more questions. Why are astronauts expected to sleep 8.5 hours per night? Who came up with that number? How was sleep measured in the astronauts? Subjective or objective information? For the astronauts that did not sleep the full 8.5 hours, were they sleepy in the daytime? Did they actually exhibit any signs of sleep deprivation? Why did the astronauts take sleep aids? Was it because they were told they needed to sleep 8.5 hours, but most realized they would not be able to do that because the amount of sleep they actually need is less?

Drowsy driving

Driving while drowsy continues to be a significant problem. It affects drivers of all age. I'm just referring to drivers who fall asleep at the wheel - also drivers who are sleep deprived enough to impair their reaction times on the road. This level of impairment can be difficult for a driver to recognize. Therefore a sleepy driver may push on, continuing to drive because they have not actually fallen asleep.

Here is a link to recent statistics from the National Highway Traffic Safety Association citing that approximately one in four motor vehicle accidents is due to drowsy driving. Someday, sleep researchers may come up with a reliable and simple test of sleepiness that drivers could use to determine if they shouldn't drive. They could take a brief nap first. Although, this all may be moot if Google makes driver-less cars a reality.

Sleep loss and psychosis

Sleep deprivation has interesting affects on our mental and physical functioning. For example, sleep deprivation tends to temporarily improve the mood of patients with depression. In fact, too little sleep can result in a manic episode in patients with bipolar disorder. This study showed that one full night of sleep depression can produce symptoms that resemble psychosis. Psychosis is a mental disorder where the person "breaks" with reality, and is part of the disorder called schizophrenia. The most common symptoms are hallucinations and delusions. The results of the study about sleep deprivation are remarkable because the psychotic symptoms occurred after only one night of sleep loss. But don't worry, the psychotic symptoms resolved completely after sleeping the next night. The researchers theorize that psychosis from sleep loss may possibly be used to study mental illness and medications used to treat mental illness.

Sleep is the new frontier of medicine

This week I am just posting a link to an article that discusses how sleep is the new frontier in medicine. It's a nice review of the importance of sleep, and how sleep affects so many different aspects of our physical and mental health.

Sleep loss and metabolic syndrome

Metabolic syndrome is a chronic disorder characterized by abdominal obesity, impaired blood sugar metabolism, high cholesterol, and high blood pressure. Here is an article about sleep loss and it's affect on our metabolism. The article is a review of the observational studies that examine the relationship between sleep deprivation and metabolic syndrome. The authors discuss some of the studies that show that acute sleep loss is linked with obesity, type 2 diabetes, cholesterol problems, high blood pressure, and even death. Of note, some of the studies show increased rates of some of these issues when people report sleeping less than or more than a specified "normal" amount of sleep. So it's not just sleep loss that is linked to problems, including mortality.

The authors note that sleep loss can affect appetite, food intake, physical activity levels, and energy expenditure. Again, these are short term studies and the reasons for the changes are not entirely clear. Results sometimes are conflicting, such as some studies showing higher levels, and other studies showing lower levels of appetite regulating hormones.

The authors conclude that sleep loss may be a "promising target for the prevention, and probably the treatment, of the metabolic syndrome and its components." Perhaps that is the case, but telling people to get more sleep is unlikely to improve their metabolic syndrome. It's certainly more complicated than that. Diet and exercise are just as important, and most likely much more so than just getting more sleep. I concede that insufficient sleep may contribute a small part to metabolic syndrome, but more long term studies are needed. And I agree with the authors when they conclude that ongoing and future studies will show whether interventions to improve sleep duration and quality can prevent or even reverse adverse metabolic traits."

The effects of sleep deprivation on facial appearance

This article received lots of press. Researchers took photographs of subjects after 8 hours of normal sleep and after 31 hours of sleep deprivation following only 5 hours of sleep the night before. The researchers then asked volunteers to list facial cues they associate with looking fatigued. The final list consisted of hanging eyelids, red eyes, swollen eyes, glazed eyes, dark circles under the eyes, pale skin, wrinkles around the eyes, rash / eczema, and droopy mouth corners. Finally, the researchers had participants rate the photographs for the fatigue cues.

The results showed that the fatigue cues were significantly found in the photographs of sleep deprived subjects - no big surprise. With the exception of glazed eyes, all of the cues that correlated with looking fatigued were also affected by sleep deprivation.

This research is interesting in that these cues for fatigue may help others determine if someone is too fatigued to be safe at work or while driving.

Sleep deprivation and food purchases

Another study linking diet and sleep. This article describes research with normal weight, healthy men after one night of sleep deprivation. Researchers gave the men about $50.00 to buy groceries the morning after a normal night's sleep or a night of sleep deprivation. After the night of sleep deprivation, the men bought more food and food that had more calories. The sleep-deprived men also had elevated levels of ghrelin, a hormone involved in appetite, but this did not correlate with food purchase behavior.

The take home message was to not go grocery shopping after a night of sleep loss. I wonder if the effect would taper for the many Americans who have chronic, partial sleep deprivation?

Sleep deprivation may contribute to prejudice and stereotyping

Here is an interesting article about research on sleep deprivation. The researcher did three studies, where she sleep deprived students and assessed their prejudice and stereotyping of others. Her results suggest that sleep deprivation may negatively impact people's expression of prejudice and stereotypes. It's not clear how sleep deprived the students were during the experiment - was it a total night of sleep loss, or chronic partial sleep loss?

In the article, the researcher is quoted saying, "In our research, we found that sleep functions as a self-regulatory resource that, when depleted, leaves people less able to control their thoughts, attitudes and behaviors in a non-prejudicial manner." And, she is quoted saying, "By having a good night's sleep and being well-rested, individuals are more likely to be able to act appropriately in situations."

Of course, being sleep deprived is no excuse for behaving inappropriately, no matter how tired we may be.

Sleep deprivation and anxiety disorders

This article describes research that shows that sleep deprivation fires up areas of the brain associated with emotional processing. This pattern is similar to the abnormal neural activity seen in anxiety disorders. The authors conclude that sleep disruption may be a key factor in anxiety disorders. Maybe. But I'm not sure you can make that statement based on the experiment. The researchers took young healthy people with no anxiety or insomnia disorders and subjected them to images after a night of good sleep and then a sleepless night. But applying the results from these healthy subjects may not be realistic for people with anxiety disorders. The authors also suggest that fixing sleep problems in anxious people may improve their anxiety condition. Perhaps, but usually if what they worry about is related to not sleeping well. I'm not yet convinced that helping people sleep better will eradicate a generalized anxiety disorder, panic disorder, obsessive compulsive disorder, or post-traumatic stress disorder. It is true that many anxiety disorders are associated with difficulty sleeping. However, the difficulty sleeping could be just an effect of the anxiety disorder. Fixing the sleep problem is less likely to help the anxiety disorder. I base this on my own experience with patients with insomnia. Some have anxiety disorders too. When I help them sleep better, their anxiety disorder does not necessarily get better. They worry less about not sleeping, but the other parts of the anxiety disorder remain.

Graph that demonstrates effects of sleep loss on performance

This article has a graph showing the effects of sleep loss on performance, and how it is similar to being intoxicated with alcohol.

Gene becomes more active with sleep loss

It's been said that an objective measurement of sleep loss could like finding the Holy Grail. It's been elusive. Here is an article that discusses research showing that a particular gene is expressed more during sleep deprivation. And this gene product could be tested in saliva samples of humans someday. It is not a measurement of sleepiness, but could indicate if a person is sleep deprived. More testing will be needed to see if the gene would be more active in people who get enough sleep, but have an untreated sleep disorder like sleep apnea.