Light from Tablet Computers May Delay Sleep, Especially in Teens

I admit I love my gadgets – especially my laptop and e-reader, I’m also, as a doctor, aware of the effects that the artificial light from these devices can have on our sleep, especially following prolonged and late-night use.

The artificial, short-wave light from TV and computer screens can suppress melatonin production and throw off circadian rhythm, preventing deep, restorative sleep. Prolonged sleep disruption may also lead to increased risk for diabetes and obesity.  A new study  released in late August reinforces my opinion with some data.

Researchers at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute in Troy, NY tested the effects of self-luminous tablets on melatonin suppression. Melatonin is a hormone produced by the pineal gland at night and is involved in regulating our sleeping and waking cycles.

The study was funded by Sharp Laboratories of America and led by Mariana Figueiro, associate professor at Rensselaer and director of the LRC’s Light and Health Program. Co-authors of the study are LRC director and professor Mark S. Rea, LRC research specialist Brittany Wood, and LRC research nurse Barbara Plitnick.

For the study, 13 participants used self-luminous tablets to read, play games and watch movies. The participants were divided into three groups. The first group viewed their tablets through a pair of clear goggles fitted with blue light. This was the “true positive” group because blue lights are known to be a strong stimulus for suppressing melatonin.

The second “control” group viewed their tablets through orange-tinted glasses, which filtered out the short-wavelength radiation that can suppress melatonin. The third group did not wear any glasses or goggles. Each tablet was set to full brightness.

The results of the study were clear: After only two hours of exposure to electronic devices with self-luminous “backlit” displays, the participants’ melatonin levels were suppressed by about 22 percent. According to lead researcher Mariana Figueiro, stimulation of the circadian system to this level may delay sleep in those using the devices prior to bedtime, especially in teens.

The researchers also determined that the type of task being performed on the tablets also determines how much light is delivered to the cornea, and therefore the impact the self-luminous light has on nighttime melatonin levels. In other words, the researchers pointed out that it is important to measure how much light a person receives from the self-luminous device.

So, what can be done with this new information? How can we use it to improve our sleep and general health? One, we can all become more aware of how much time we—and our children—spend staring at our tablets, computer and TV screens late at night. As adults, it is up to us to monitor ourselves and our children, and have the discipline to turn these machines off at least an hour before bedtime.

LRC research specialist Brittany Wood said, “Technology developments have led to bigger and brighter televisions, computer screens, and cell phones. To produce white light, these electronic devices must emit light at short wavelengths, which makes them potential sources for suppressing or delaying the onset of melatonin in the evening, reducing sleep duration and disrupting sleep. This is particularly worrisome in populations such as young adults and adolescents, who already tend to be night owls.”

Although pre-teens and teens love their late-night electronics, as parents, it is our responsibility to monitor our children’s computer use, or at the very least in older teens, educate them and make them aware of the potential; side effects of prolonged use.

Researcher Figueiro also feels that tablet display manufacturers can use this information to determine how their products affect circadian system regulation, and as a result, design more “circadian-friendly” electronic devices that could either increase or decrease circadian stimulation depending on the time of day. For example, screens that reduce circadian stimulation in the evening for a better night’s sleep, and increasing in the morning to encourage alertness.

Figueiro had another interesting idea about tablet light therapy: In the future, manufacturers might be able to use related data to design tablets that minimize symptoms of seasonal affective disorder, and sleep disorders in seniors. People might even be able to receive light treatments while playing games or watching movies, making light therapy much more enjoyable than just sitting in front of a light box.

Until manufacturers develop more “circadian-friendly” electronic devices that increase or decrease light exposure based on time of day, Figueiro offered several recommendations to reduce the effects of self-luminous tablet light on sleep, including dimming these devices at night as much as possible in order to minimize melatonin suppression, and, as I mentioned before, limiting the amount of time spent using these devices prior to bedtime.

Here’s another idea: Why not turn off the devices before bed, and pick up a good old fashioned paper book. You’ll be out like a light before you know it.

Read the full study entitled, “Light From Self-Luminous Tablet Computers Can Affect Evening Melatonin, Delaying Sleep.”

The Link Between Sleep Apnea and Cancer—Evidence is Mounting

September is back to school month for many of our children — it’s also a good time for adults to learn about health issues, so here is some information to help you become educated about the health risks associated with untreated sleep apnea. Evidence is mounting: severe obstructive sleep apnea (OSA) may be linked to a higher risk of dying from cancer.

The results of three recent studies in Spain were presented in early September at the European Respiratory Society’s (ERS) Annual Congress in Vienna. The data presented by the Spanish researchers reinforces the results of previous studies which show similar links between severe OSA and cancer death. 

While scientists have yet to prove 100% that sleep apnea causes a higher risk of cancer death, more and more studies are showing the link. When obstructive sleep apnea occurs, a person’s airway becomes obstructed during sleep, blocking air flow and causing the person to wake suddenly, often gasping for air. This can happen hundreds of times a night, causing a person’s blood oxygen level to drop abnormally low.

Many researcher theorize that the lack of adequate oxygen supply, known as intermittent hypoxia, caused by OSA causes increased vascular growth and tumor growth because poor breathing fails to oxygenate the cells sufficiently.

Thankfully, people with sleep apnea can be treated using multiple methods. One of the most effective is continuous positive airway pressure (CPAP) therapy, which generates a stream of air to keep the upper airways open during sleep.

Let’s look at some recent sleep apnea and cancer studies out of Spain. Dr. Miguel Angel Martinez-Garcia from La Fe University Hospital in Valencia, Spain, and his fellow researchers studied more than 5,600 sleep apnea patients from seven different sleep clinics in Spain. The researchers measured the severity of a patient’s sleep apnea, based on the number of times during the night that a patient’s blood oxygen level dropped below 90 percent oxygen saturation.

The results of the study showed that people with sleep apnea who spent more than 14 percent of their sleep time with oxygen saturation levels below 90 percent not only had severe sleep apnea, but were approximately double the relative risk of dying due to cancer than people without sleep apnea. The researchers also found a significant increase in the relative risk of dying from cancer in people with less severe sleep apnea. This association was even higher in men and younger people.

Lead researcher Dr. Martinez-Garcia stated that the results do not mean unequivocally that sleep apnea causes cancer—it means the researchers found an association between the two disorders. However, the results of the experiment add to growing evidence that there is a clear link between sleep apnea and cancer mortality. 

Research from two other Spanish studies presented at the European Respiratory Society’s Annual Congress showed an increase in cancer incidence in humans, as well as an association between sleep apnea and the spread of cancer in mice.

The second study showed an increase in all types of cancer in people with severe sleep apnea, even when other factors such as age, sex and weight were taken into account. In a third study, Spanish researchers used mice to study the spread of melanoma skin cancer, and whether this was associated with sleep apnea.

The results showed that the spread of cancer was more abundant in mice that had experienced low levels of oxygen as in sleep apnea, than those who breathed normal air during the experiment.

According to the study’s lead author, Professor Ramon Farre from the University of Barcelona in Spain, the results of the mouse study strongly suggests a link between sleep apnea and the spread of cancer, and encourages further research to better understand the links between sleep apnea and cancer.

I agree with Professor Farre that these recent studies offer compelling evidence, and it is our responsibility in the medical and scientific communities to continue researching and testing to better understand the link between sleep apnea and cancer. 

Read the full study, Sleep Apnoea Linked with Increased Risk of Cancer Death.

Less Than Six Hours Sleep/Night Increases Strokes

Lack of sleep and an increase in strokes. According to new research, the two conditions are very connected, even in otherwise healthy adults.

In early June, the University of Alabama at Birmingham released the results of a study that regularly sleeping less than six hours a night significantly increases the risk of stroke symptoms in middle-age to older adults who are of normal weight and at low risk for obstructive sleep apnea (OSA). That’s worth repeating: Less than six hours of sleep per night increases the risk of strokes in adults of normal weight and not at risk for OSA.

It seems that under six hours of sleep per night is the critical variable, but why? Let’s take a look at the study. The University of Alabama researchersfollowed 5,666 people  for up to three years who had no history of strokes or stroke-like symptoms, transient ischemic attacks (when blood flow to the brain stops for a brief period causing stroke-like symptoms), or high risk for OSA at the start of the study.

For a period of three years, the researchers followed and studied the subjects’ first stroke symptoms, stroke risk factors, depression symptoms, demographic information and other various health behaviors. What they found was—after adjusting for body-mass index (BMI)—there was a strong association between daily sleep periods of less than six hours and a greater incidence of stroke symptoms for middle-age to older adults, even beyond other risk factors. Interestingly, the researchers did not find any link between short sleep periods and stroke symptoms in overweight and obese participants.

Still, the connection between short sleep and strokes is worthy of great attention from the medical community and general public. I agree with the Alabama study’s lead author, Megan Ruiter, PhD., who said, “The results of the Alabama study provide a strong argument for increasing physician and public awareness of the impact of sleep as a risk factor for stroke symptoms, especially among persons who appear to have few or no traditional risk factors for stroke.”

It looks like the medical community is taking this message to heart. Another study announced in late July is going on at the Alberta Health Services and the University of Calgary.  There, Dr. Patrick Hanly of the university’s Hotchkiss Brain Institute is leading a study to learn more about the physiological connection between sleep apnea and stroke—specifically, the brain’s blood flow response in people with and without sleep apnea.

For the study, participants with sleep apnea stay overnight in the sleep laboratory at Calgary’s Foothills Medical Centre, where their breathing and cardiovascular responses are continuously monitored while they sleep. The next day, their brain blood flow response to reduced oxygen levels is assessed while they are awake. Then, the participants receive supplemental oxygen during sleep for two weeks, and are tested again to see if their cerebral defense mechanisms have improved. The researchers are also studying people without sleep apnea to see if their cerebral defense mechanisms function better than in those with sleep apnea. Hanly and team’s theory is that it is the lack of oxygen, or hypoxia, that people with sleep apnea experience during sleep that impairs the body’s normal defense mechanisms in the brain. A better understanding of this connection will lead to better prevention and treatment strategies.

I applaud the work of the Alabama and Calgary researchers. It’s time we all wake up to the health benefits of more–and better—sleep.

For more information, read the University of Alabama at Birmingham study, “Under 6 Hours of Sleep Tops Risks for Stroke in a Low-risk Population.”

Heavy Technology Use linked to Fatigue, Stress and Depression in Young Adults

Modern technology is affecting our sleep. The artificial light from TV and computer screens affects melatonin production and throws off circadian rhythms, preventing deep, restorative sleep.

New research out of the University of Gothenburg, Sweden reinforces this fact, specifically relating to young adults. Doctoral student Sara Thomée and her colleagues at the University of Gothenburg's Sahlgrenska Academy conducted four studies to find out the effects of heavy computer and cell phone use on the sleep quality, stress levels, and general mental health of young adults.

For the study, Thomée and her team asked 4,100 young adults between age 20 and 24 to fill out questionnaires. They also interviewed 32 of them who were considered heavy information and communication technology (ICT) users. The researchers analyzed and compiled the data, and the results revealed that intensive use of cell phones and computers can be linked to an increase in stress, sleep disorders and depressive symptoms in young adults.

Some of the more specific findings are:

• Heavy cell phone use showed an increase in sleep disorders in men, and an increase in depressive symptoms in both men and women. 

• Those constantly accessible via cell phones were the most likely to report mental health issues.  

• Men who use computers intensively are more likely to develop sleeping problems.
• Regular, late night computer use is associated with sleep disorders, stress and depressive symptoms in both men and women.
• Frequently using a computer without breaks further increases the risk of stress, sleeping problems and depressive symptoms in women.
• A combination of both heavy computer use and heavy mobile use makes the associations even stronger.

So, what’s behind this link between technology use and negative health symptoms? The researchers have not yet fully determined why heavy technology users are more likely to have sleep disorders, higher stress and mental health issues, but one theory is that people with these symptoms are more likely to reach out and contact friends and family via technology.

I tend to think that the relationship between technology and stress, sleep disorders and depression has more to do with the overuse of technology in our society, especially among young people. If you’re a parent like I am, than you know first-hand how difficult it can be to get children to turn off the computer or put down their phone and stop texting so you can, just maybe, have a real conversation.

This is a growing and serious public health hazard that should be acknowledged and addressed by both the medical community and technology industry. It’s been scientifically proven that the light from TV and computer screens affects melatonin production and melanopsin stimulation, and throws off our circadian rhythms. This interrupts or prevents deep, restorative sleep, causing an increase in stress and depressive symptoms.

In the words of head researcher Sara Thomée, "Public health advice should therefore include information on the healthy use of this technology.” I couldn’t agree more. Just like alcohol ads, so should technology companies carry warnings on their products and in their advertisements. “Text responsibly.” “Don’t surf, then sleep.” You get the idea.

What can we, as individuals, do to protect our health from the negative impact of the ubiquitous technology in our society? Quite simply, turn it off, and get some good sleep. When you are on the computer for any length of time, take more frequent breaks, and impose limits on the amount of time you spend online. Trust me, the world will wait patiently for another Facebook post or text from you.

Remember, people need an average of seven to eight hours of restful sleep to fully take advantage of its restorative power and avoid daytime symptoms of fatigue. So turn off your TV and computer at least one hour before you go to sleep. Don’t sleep with your cell phone on and next to your bed. (Few things are more frustrating than being awakened in the middle of the night by an unimportant text message.)

Re-claim your bedroom for its intended purpose: restful sleep. Move the TV and computer out of the bedroom, or at the very least, don’t watch TV or work on the computer too close to bedtime. Stick to a bedtime routine. Get at least 7-8 hours of sleep every night. Try to go to sleep and wake up around the same time every day, even on weekends. Try to keep to within 20 minutes of the same time each morning and night.

Before bed, do activities that will promote sleepiness, such as a taking a warm bath, or reading a book or magazine. It also helps to maintain a cool temperature in your bedroom. A cool but comfortable temperature is ideal for sleep. Too warm and you will be fitful, too cold however can be uncomfortable and disturb your sleep.

Exercise regularly but not after the late afternoon. Even though exercise helps regulate sleep, rigorous exercise causes endorphins in the body to circulate which can have a stimulant effect, and keep you awake longer at night.

Stay away from caffeine at night. The effects of caffeine are different from person to person, and may last hours after your last cup of coffee, so make your last cup of coffee, regular tea or soda earlier in the day. Avoid alcohol and medicines that make you drowsy. Even if you think it is helping you fall asleep initially, alcohol and medicines that makes you drowsy may affect your sleep throughout the night.

And finally, if you feel that you are suffering from persistent sleep disorder, get checked out by a qualified sleep doctor. Regular, healthy sleep is one of the best things you can do for your mental and physical health.

Read the full report, entitled, “Intensive Mobile Phone Use Affects Young People´s Sleep.”

Lack of Sleep is Stressing Us Out, New Study Says

Stress in our life is not only caused by what we do and our busy schedules—stress is also caused by what we don’t do, namely, not get enough sleep. A new study by researchers in England and the Netherlands have discovered that a severe lack of sleep creates a response in the immune system that is similar to the body’s immediate response when it experiences a stressful situation. Yes, even lack of sleep is stressing us out.

The study was a joint effort by the Department of Forensic Molecular Biology at the Erasmus MC University Medical Center in Rotterdam and the Centre for Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, and the University of Surrey Clinical Research Centre in England.

So how did the researchers determine this? They compared the white blood cell counts of 15 healthy young men under both normal and severely sleep-deprived conditions.

In the first phase of the study, the men followed a strict schedule of eight hours of sleep per night every day for one week. They were also exposed to at least 15 minutes of outdoor light within the first 90 minutes of waking, and prohibited from using caffeine, alcohol or medication during the final three days of the first week.

The researchers required this in order to stabilize the participant’s circadian clocks and minimize sleep deprivation before the second phase of the study. The researchers then categorized and measured each participant’s white blood cells.

In the second phase of the study, the men stayed awake for 29 continual hours, and their white blood cells were again recorded and compared to the white blood cell numbers collected in the first phase of the study.

According to the researchers, the effect of sleep loss on the white blood cells was immediate. The white blood cells known as granulocytes showed a loss of day-night rhythmicity—the circadian rhythm of the granulocytes slowed—and their numbers also increased, particularly at night. This reaction directly mirrors the body’s white blood cell response to stress.

Read the full study entitled, “Diurnal Rhythms in Blood Cell Populations and the Effect of Acute Sleep Deprivation in Healthy Young Men,” published in the July 2012 issue of the journal, Sleep. 

The results of the study are in line with other previous research that shows a link between lack of sleep and a negative immune system response. In March of this year, the University of Rochester Medical Center published results that showed that the immune system of older adults who do not get enough sleep responds to stress with inflammation, increasing the risk for mental and physical health problems.

These studies and others like them reinforce the fact that more quality, restful sleep not only helps us feel better – it may also help us avoid myriad poor mental and physical health conditions. So, get some sleep out there — you’ll feel less stressed out!

“Social Jetlag” Contributing to Global Weight Gain

Here’s another reason to get more sleep — and another new term to describe one of our modern maladies: “social jetlag.” What exactly is social jetlag? It is a syndrome caused by the discrepancy between our internal body clock and our social clock. And according to Professor Till Roenneberg, Ph.D. at the University of Munich's Institute of Medical Psychology in Germany, that gap between how much sleep we need and how much we’re actually getting is contributing to our global weight gain and the growing worldwide obesity epidemic.

Each of us has a physiological clock, and that internal clock — also known as our circadian rhythm — is regulated by daylight and darkness to prompt us to go to sleep or wake up. We also have a social clock of things that make up our daily lives, such as our work schedules and social calendars. The problem is, in our modern society of too-late work hours and too much time in front of computer screens, we are listening to our social clocks more than our physiological clocks, causing a greater sleep gap known as social jetlag. As a person’s circadian rhythm gets more out of whack, their physiological clock gets set later and later, keeping them awake into the night, and feeling chronically tired during the day.

Professor Roenneberg and his fellow researchers in Munich discovered the negative effects of social jetlag after compiling and studying the sleep habits of more than 65,000 adults over the past 10 years. Roenneberg and his team recorded sleep times and other data of the participants, such as height and weight, and started to draw conclusions.

The results of the study — which you can read in the May 10 issue of Current Biology — showed that people with different weekday and weekend sleep schedules—i.e., those with more social jetlag — were three times more likely to be overweight. That is a significant increase worth repeating: Three times more likely to be overweight!  Furthermore, the body mass index (BMI) of the overweight participants tended to increase as the gap between their weekday and weekend sleep clocks widened.

Two-thirds of participants reported at least one hour's difference in their average weekday and weekend sleep schedules, and more than 10 percent reported three-plus hours difference between their weekday and weekend sleep schedules. Roenneberg and his colleagues also found that people who are chronically sleep-deprived are also more likely to smoke and drink more alcohol and caffeine.

The results of the study are similar to those of previous studies linking a higher body mass index and even diabetes to the irregular sleep schedules and sleep deprivation of shift workers. But I applaud the efforts of Roenneberg and his team for their work in particular, because they are bringing a public awareness of a growing syndrome that is affecting many people worldwide — not just shift workers or those with irregular work schedules.

So, why does social jetlag cause weight gain? One of the theories is that late hours encourage irregular meal times and late-night eating, when the body has more difficulty digesting and metabolizing food. That translates into body fat. Another is that chronically tired people are less likely to exercise and more likely to smoke and drink, further contributing to weight gain.

Whatever the causes, it is in all our personal best interests to become more aware of our own physiological clocks and get more restful sleep. Doing so can help us all maintain a healthy body weight, avoid many health problems, feel better and live happier, more productive lives. In the words of Professor Roenneberg, “Good sleep and enough sleep is not a waste of time but a guarantee for better work performance and more fun with friends and family during off-work times.” Knowledge of the study and an increased awareness of the effects of social jetlag can also have positive effects on the economy and education: Companies can make more informed decisions about employees’ work schedules and schools can make more educated decisions about school hours.

So, now that you have this new knowledge about social jetlag, your physiological and social clocks and how a gap between your weekday and weekend sleep schedules can contribute to your weight gain, what are you going to do about it? I present you with a personal challenge that will only help you feel better. I challenge you to get more sleep. Turn off the TV and computer and go to bed earlier. Forego that invitation for a late-night dinner. Spend more time outdoors, and if you’re stuck in an office all day, try to sit near a window. I promise you, you’ll feel less social jetlag.

To read Professor Roenneberg and his team’s full report entitled, “Social Jetlag and Obesity,” published in the May 10 issue of Current Biology.

Ready to Treat Your Sleep Apnea? You Have Options.

This month’s blog is for anyone who has been diagnosed with obstructive sleep apnea (OSA) and is currently using or considering using a Continuous Positive Airway Pressure (CPAP) machine while sleeping.

Many patients are not happy about the prospect of sleeping with an mask on. If you do opt for CPAP therapy, realize that CPAP machines have come a long way. If you’re adamant you do not want to use a CPAP mask, thankfully, you have options.

First, I want to briefly explain what obstructive sleep apnea does to a person’s nighttime breathing. When you fall asleep, your muscles relax, and the soft palate at the back of the throat can sag. When this happens, the upper airway can become obstructed, causing the soft palate and uvula to vibrate, causing snoring.

When the airway is completely obstructed, breathing stops for a period of time, until the body is jerked awake in reaction. This is obstructive sleep apnea. OSA can cause interrupted breathing hundreds of times a night, usually around 20 seconds per pause.

This paused breathing causes waking through the night, preventing deep, restorative sleep. This often leads to a host of problems, from daytime sleepiness and reduced job performance to hypertension,heart disease, mood and memory problems.

A CPAP machine helps this condition by pumping a continuous flow of air into the nasal passages, keeping the airway open, and preventing or greatly reducing snoring and paused breathing.

Many people don’t like wearing the nasal mask for CPAP therapy. Some feel claustrophobic or claim it causes dry mouth, nasal congestion or skin irritations. Realize there are different machines out there, so it’s important to choose the right machine for you—choose a small, quiet machine with a comfortable mask that fits you well. A humidifier attached to the CPAP machine can reduce throat dryness.

If CPAP therapy is not for you, there are some non-surgical treatment options. One of the latest is the Pillar Procedure, a safe, non-invasive treatment for mild to moderate OSA symptoms. During the Pillar Procedure, three tiny polyester implants are placed into the soft palate through a small delivery tool without incisions or stitches. Over the following weeks, the implants, together with the body's natural fibrotic response, stiffens the upper palate and creates structural support. This reduces the tissue vibration that causes snoring and the tissue collapse that causes obstructive sleep apnea. I do the Pillar Procedure at my Eos Sleep office, and it usually takes around 20 minutes.

Another is a more comfortable alternative to CPAP, called the Provent Device. This FDA-approved treatment involves a small nasal valve that fits into the nostrils and is secured by an adhesive bandage. The valve is powered by your own breathing and creates positive airway pressure much like CPAP, but does not require a machine or mask.

Bilevel Positive Airway Pressure (BiPAP) is similar to CPAP therapy, but the machine has two air pressure levels, one for breathing in and one for breathing out. The air pressure for breathing out is usually set lower than the incoming air, and you may find it more comfortable to breathe out against a lower air pressure.

Whatever OSA treatment option you choose, you owe it to yourself to seek proper treatment and use your chosen therapy regularly.  The benefits are great—snoring and paused breathing will be reduced or eliminated, helping you—and your partner—to sleep and feel better during the day.