Sleep apnea causes systemic inflammation: CPAP can help

By Dr. David O. Volpi

If you, or someone you know, have been diagnosed with obstructive sleep apnea (OSA), you’re probably familiar with a treatment called CPAP, or Continuous Positive Airway Pressure.

While some people find the mask worn for CPAP treatment uncomfortable—more on that later—it has been proven to be a highly effective way to keep the airways open that become obstructed in sleep apnea patients, and reduce or prevent snoring and paused breathing.

There’s a new study that found that CPAP treatment also reduces the systemic inflammation caused by sleep apnea, usually in the bronchial and nasal passages.

Systemic inflammation is the chronic biological response, or inflammation, of blood vessel tissues due to dangerous or foreign elements, such as pathogens or damaged cells. It is increasingly being recognized that systemic inflammation is a risk factor for a number of health complications, including atherosclerosis, and is a well-established factor in the development of cardiovascular disease.

The new study published March 22 in the Journal of Inflammation found that treating OSA with a CPAP machine helps to lower systemic inflammation, which might prevent some of the other problems associated with OSA. The source of the research was the PubMed, Embase and Cochrane library.

Here’s a refresher on how CPAP machines help OSA patients: When you fall asleep, your muscles relax, and the soft palate at the back of the throat may 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 known as 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—via a mask worn at night—keeping the airway open—and preventing or greatly reducing snoring and paused breathing.

To find out if CPAP treatment reduces inflammatory symptoms or “markers” in OSA patients, the researchers pooled data from 24 trials involving more than 1,000 patients. The resulting data suggested that treating OSA with CPAP significantly reduces levels of two proteins associated with systemic inflammation: tumor necrosis factor and C-reactive protein (CRP).

While more study is needed, the researchers believe that reducing systemic inflammation in OSA patients with CPAP treatment may be one way to reverse some of the long-term health disorders associated with OSA.

If you or someone you know is considering Continuous Positive Airway Pressure (CPAP) treatment, you'll need a sleep study to diagnosis whether or not you have sleep apnea, and a sleep specialist will recommend the correct CPAP machine, or treatment, for you.

Sleep Improves Children’s Ability to Absorb Information and Learn

By Matthew D. Mingrone, M.D. of eOs Sleep

It has been common scientific knowledge for some time that when people sleep, our brains consolidate the information we subconsciously absorb during the day, and process it into explicit, conscious knowledge.

Both children and adults do this, but an interesting new study out of Germany shows that during sleep, children's brains convert subconsciously absorbed information—known as implicit learning—into active, useful knowledge even more effectively than adult brains do.
Implicit learning is typically considered subconscious learning; the acquisition of knowledge independent of conscious attempts to learn. For example, a child can say a sentence without understanding the rules of English grammar.

Explicit learning, on the other hand, is deliberate, conscious learning; the active and aware acquisition of skills and/or knowledge. Typically, explicit learning is accompanied by “meta-awareness,” a person can explain how they acquired the skill and/or knowledge.
When we sleep, implicit knowledge becomes explicit memory, making it easier for us to recall and use the information we have previously absorbed.

In a new study conducted by Dr. Ines Wilhelm of the University of Tübingen's Institute for Medical Psychology and Behavioral Neurobiology in Germany, and colleagues, the researchers studied 35 children between the ages of 8 and 11 years old, as well as 37 adults between 18 and 35.

For the test, the subjects were asked to press a sequence of buttons after they lit up. Half of the subjects did the test before sleep, the other half after sleep. They were then asked to recall the sequence of buttons/lights 10 to 12 hours later. Following a night of sleep or a day awake, the subjects’ memories were tested.

An article explaining the results of the study, entitled, “The sleeping child outplays the adult's capacity to convert implicit into explicit knowledge,” is published in the February 24, 2013 online edition of Nature Neuroscience.

The authors observed that after a night’s sleep, both age groups—8 to 11 and 18 to 35—remembered a larger sequence of buttons/lights than those who did not sleep. It also showed the children were better at it than the adults—almost all of the children could remember the sequence they had pressed perfectly, while adults experienced smaller gains.

Lead author Dr. Ines Wilhelm wrote, “In children, much more efficient explicit knowledge is generated during sleep from a previously learned implicit task. And the children’s extraordinary ability is linked with the large amount of deep sleep they get at night. The formation of explicit knowledge appears to be a very specific ability of childhood sleep, since children typically benefit as much or less than adults from sleep when it comes to other types of memory tasks.”

Children absorb massive amounts of information every day. They also generally sleep longer and deeper, and experience three times more slow-wave sleep and higher electrical activity in the brain during sleep than adults. This may help them “convert” the information they take in every day into knowledge they can recall and use. This is yet another important reason why parents should ensure their children are getting enough uninterrupted sleep every night.

A Good Night’s Sleep Can Be a Matter of Life and Death

Over the past three years, I have been writing the Wake Up! You’re Snoring blog with two main objectives: first, to educate you, the public, about sleep disorders, and second, to provide compelling reasons—preferably scientific evidence—why a person who may have a sleep disorder should get diagnosed and, if necessary, properly treated.

There is no shortage of scientific studies being released on a regular basis showing links between obstructive sleep apnea (OSA), insomnia, and other sleep disorders, and myriad negative health conditions, from daytime sleepiness to increased depression.

I wasn’t surprised to see a new study showing a link between insomnia, the loss of hope, and an increased risk of suicide. In a study led by Dr. W. Vaughn McCall, chair of the Medical College of Georgia at Georgia Regents University, researchers studied the mental state of 50 depressed patients between the ages of 20 and 80. More than half of the patients had attempted suicide, and most were taking an antidepressant.

It is established that insomnia and nightmares often go hand-in-hand, and are both known risk factors for suicide. The new study reaffirms that link, but researchers also wanted to find out what effect feelings of hopelessness about sleep had on suicide risk.

In the study, the researchers specifically focused on the relationship between insomnia and suicide risk by asking questions about dysfunctional beliefs about sleep, such as, “Do you think you will ever sleep again?” The scientists used psychometric testing to objectively measure the mental states and personalities of the 50 depressed patients.

Dr. McCall published the results of the study in the Journal of Clinical Sleep Medicine, the journal of the American Academy of Sleep Medicine. In the report, Dr. McCall stated, “It turns out insomnia can lead to a very specific type of hopelessness, and hopelessness by itself is a powerful predictor of suicide.” Dr. McCall also said, “The likelihood of being suicidal at least doubles when insomnia is a symptom.”

McCall and his colleagues have, in effect, discovered a new predictor for suicidal thinking. But why the link between lack of sleep and suicidal thoughts? Dr. McCall explained that, “It turns out insomnia can lead to a very specific type of hopelessness, and hopelessness by itself is a powerful predictor of suicide.” He continued, “If you talk with depressed people, they really feel like they have failed at so many things. It goes something like, ‘My marriage is a mess, I hate my job, I can’t communicate with my kids, I can’t even sleep.’ There is a sense of failure and hopelessness that now runs from top to bottom, and (insomnia) is one more thing. It was this dysfunctional thinking — all these negative thoughts about sleep — that was the mediating factor that explained why insomnia was linked to suicide,” said McCall.

The significance of this study, like many others, is that it not only educates people about the risks associated with insomnia and other sleep disorders, but it challenges the medical community to look at things a little differently when diagnosing and treating.

In this case, examine lack of sleep and insomnia when treating depression and suicidal thinking.  The finding also is a reminder to physicians that depressed patients who report increased sleep problems should be asked if they are having suicidal thoughts, McCall said.

If you’re having trouble sleeping, here are some tips to increase your chances of getting a good night’s sleep.

• Use the bedroom for sleep. With so many electronic distractions in our lives, it’s important to re-claim your bedroom for its intended purpose: rest and sleep. Move the TV and computer out of the bedroom, or at the very least, do not watch TV, work on the computer or check your blackberry close to bedtime.
• Stick to a bedtime routine. Try to go to sleep before 10:00 pm at night, 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.
• Do activities that will get you ready for bed. Before bed, do activities that will promote sleepiness, such as a taking a warm bath, or reading a book or magazine.
• 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.

Remember, people need an average of 7-8 hours of restful sleep to fully take advantage of its restorative power and avoid daytime symptoms of fatigue. If a regular, peaceful routine incorporating the tips above doesn’t help you start sleeping peacefully throughout the night, contact your doctor. You may have a more serious cause of sleeplessness such as snoring, sleep apnea or chronic insomnia. Getting treated could prevent heart disease, hypertension and stroke.

Snoring a Top Predictor of Heart Attacks and Strokes

By Dr. David O. Volpi

I read a study recently that I immediately knew I had to make you aware of.

Researchers at Henry Ford Hospital in Detroit found that snoring is a bigger risk factor for heart disease, including stroke and heart attacks, than being overweight, having high cholesterol, and even smoking! Yes, you read that right—snoring is an even bigger risk factor for heart disease.

The study, which was submitted to The Laryngoscope journal, is the first of its kind to show a link between snoring and heart disease, similar to other risk factors, such as sleep apnea, obesity, smoking and high cholesterol are also linked to heart disease.

Snorers showed arterial damage

For the study, Dr. Robert Deeb, MD, and senior study author Karen Yaremchuk, MD, reviewed the data of 913 patients, all between the ages of 18 and 40, who had been evaluated by the Henry Ford sleep center between December 2006 and January 2012.

The researchers noticed that the carotid arteries—the arteries that supply oxygen-rich blood to the brain—had thickened among the snorers, indicating that arterial damage had occurred due to snoring.

The researchers hypothesized that the thickening of the artery walls could have been due to the trauma and inflammation caused by snoring. But previous research on sleep apnea and artery disease has found the opposite: arterial damage comes first, reducing the oxygen level in the blood, leading to interruptions in breathing. The thickening of the arteries may also be contributing to the snoring in the patients.

Even more interesting: The snorers’ arterial walls had thickened, even though none of the patients had been diagnosed with obstructive sleep apnea (OSA). While OSA often develops from snoring and has been known as an indicator of cardiovascular disease, there’s been little evidence until now to prove that arterial damage can actually begin with snoring.

What these results mean

So what are the medical implications of the Henry Ford study? Let’s review coronary artery disease for a moment. Coronary artery disease (CAD), also known as atherosclerosis, occurs when waxy plaque builds up on the inner walls of the arteries.

Over time, the arterial walls thicken and stiffen, restricting blood flow to the heart and/or brain. It is commonly know that CAD is a precursor to conditions such as heart attack, stroke, and heart failure.

The results of the Henry Ford study—that the carotid arteries had thickened among the snorers, is important to pay attention to because it means that snoring, not just OSA, is a high risk factor for coronary artery disease, heart disease, and other related conditions.

Drs. Deeb and Yaremchuk’s research is groundbreaking because arterial blockage and other forms of heart disease are usually detected only after significant permanent damage has been done.

This new research should encourage snorers—and those who love them—to visit a doctor to discuss cardiovascular health and stroke prevention, and get properly diagnosed and treated.

The research is clear that doctors should add snoring to the list of coronary artery disease risk factors, along with high blood pressure, high cholesterol, diabetes, smoking and family history. Perhaps if patients and their doctors considered snoring a serious health threat and treated it accordingly, there would be a great reduction in heart disease.

Women with Sleep Apnea Show Higher Brain Damage, Anxiety than Men

An estimated 18 million Americans have obstructive sleep apnea (OSA), including one in four women over 65, according to the National Sleep Foundation.

And several recent studies have linked OSA to health disorders specifically in women. Sleep apnea has been linked to dementia in older women,  and another observational study found that women with untreated severe OSA are 3.5 times more likely to die from cardiovascular disease than women without OSA.

Here’s another reason for women to take sleep apnea seriously: A first-of-its-kind study out of the UCLA School of Nursing discovered that women with sleep apnea are more likely to suffer a higher degree of brain damage than men with sleep apnea.

What is obstructive sleep apnea? OSA is a disorder that occurs when a person's breathing is repeatedly interrupted during sleep, sometimes hundreds of times a night. During each obstruction, the oxygen level in the blood drops, which over time, causes myriad health problems. For people with sleep apnea, the combination of disturbed sleep and oxygen starvation may lead to hypertension, heart disease and mood and memory problems, among other disorders.

The new UCLA study

UCLA has been on the cutting edge of sleep apnea research. About 10 years ago, the same UCLA research team that conducted the new study was the first to show that men with OSA have damage to their brain cells.

For the latest multi-year study, entitled "Sex Differences in White Matter Alterations Accompanying Obstructive Sleep Apnea,” the researchers studied patients diagnosed with OSA at the UCLA Sleep Laboratory. They compared the nerve fibers in the patients' brains, known as “white matter,” to the nerve fibers of people without OSA or other sleep problems. The goal was to find the differences in brain damage, if any, between men and women with OSA.

Results of the study

The researchers found that women are actually more affected by sleep apnea than men. Additionally, women with OSA have more severe brain damage than men suffering from a similar condition. The women with sleep apnea also showed higher levels of depression and anxiety symptoms.

Specifically, the study found that women were impacted in the cingulum bundle and the anterior cingulate cortex areas in the front of the brain involved in decision-making and mood regulation.

Based on the results, chief investigator Paul Macey said, “Doctors should consider that OSA in women may be more problematic and therefore need earlier treatment in women than men.”

With the results of this study as a foundation, the next step is for the researchers to find out if treating sleep apnea can help the brain.

In a “chicken or egg” scenario, did the OSA cause the brain damage, or did the brain damage cause the OSA?  Or did the common conditions, such as depression, dementia or cardiovascular issues cause the brain damage, which in turn leads to sleep apnea?

The study and resulting questions are fascinating, and one thing is for sure: both men and women who are having trouble sleeping should get checked for obstructive sleep apnea and other sleep disorders.

Researchers estimate that up to 85 percent of people with severe sleep apnea have not been diagnosed yet.

Many times, sleep apnea can be misdiagnosed as chronic fatigue, insomnia, depression, or some other non-specific condition, so be specific about the symptoms you are experiencing.

Don't wait to get checked—it could save your life, or someone you love.

For more information, read the article, “Women with sleep apnea have higher degree of brain damage than men, UCLA study shows.”

Can more sleep help ease pain? Yes, says new study!

Chalk another one up for the benefits of sleep. Researchers at the Sleep Disorders and Research Center at the Henry Ford Hospital in Detroit have found that getting more sleep improves daytime alertness and reduces pain sensitivity in healthy adults.

The study was led by Timothy A. Roehrs, Ph.D. of the Sleep Disorders and Research Center at the Henry Ford Hospital and supported by the Fund for Henry Ford Health System. Roehrs and his colleagues studied 18 pain-free, but mildly sleepy volunteers.

For the study, the participants were randomly assigned to four nights of either their normal amount of sleep, or extending their sleep time to 10 hours in bed per night. Their daytime sleepiness was measured on days one and four using the Multiple Sleep Latency Test (MSLT), a tool that measures how quickly a person falls asleep. Their pain sensitivity was also measured using finger withdrawal latency pain testing to a radiant heat stimulus.

The first study to prove sleep reduces pain.

The results of the study were published in the Dec. 1 issue of the journal Sleep. It is the first research of its kind to prove that extended sleep in mildly sleep-deprived adults can significantly reduce their sensitivity to pain.

The results showed that the extended sleep group—those who slept more than normal—slept 1.8 hours more per night than the normal sleep group. It also showed that they experienced less daytime sleepiness. This increase in sleep time during the four nights correlated to increased daytime alertness, as well as less sensitivity to pain.

Regarding the pain test, the extended sleep group showed a greater tolerance for pain/reduced pain sensitivity. The length of time before participants removed their finger from a radiant heat source increased by 25 percent. The researchers noted that this increase in “finger withdrawal latency” is greater than the effect found in a previous study where participants used 60 milligrams of codeine.

In their report, the researchers stated that the results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.

Timothy Roehrs, PhD, the study’s principal investigator and lead author said, “The results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures. We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine.”
Read the press release for the study, “Extended sleep reduces pain sensitivity.”

Lack of sleep and an increase in strokes.

Roehrs’ study adds to growing evidence that more regular, restorative sleep can help reduce the risk of health problems, and the opposite is true, as well.

Last 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 researchers followed 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, no pun intended. 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 regular, restorative 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.”

Is the quality of your sleep making you gain weight?

How many of us would like to lose a few pounds, but look for external ways—outside of our bodies—to lose weight?  Perhaps we should be looking more inward, not only at our personal diet and exercise levels, but the length and level, or phase, of our sleep.

Recently, I read an article in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. In it, researchers from St. Luke's-Roosevelt Hospital and Columbia University in New York shed some light on the link between our length and phase of sleep, and hunger and weight gain.

The researchers investigated the effects of “sleep architecture” on hunger to determine whether specific stages of sleep—not just the duration of sleep—affect the appetite and food cravings in healthy adults.

What they found is compelling, and cause for further attention: the length of time of sleep, as well as the percentage of overall sleep in different sleep stages, are associated with decreased metabolic rate, increased hunger, and increased intake of calories, specifically from fat and carbohydrates.

For the study, head researcher Ari Shechter and his colleagues studied a random sample of 27 healthy adults between the ages of 30 and 45. The participants underwent two six-day periods of laboratory observation, during which they were slept different lengths of time.

During a "habitual sleep" phase, they were allowed to sleep for nine hours; in the "short sleep" phase, they were allowed just four hours of sleep. Each of the two sleep phase studies were separated by four weeks to make sure the participants fully recuperated, and the women were observed at the same phase of their menstrual cycle. The amount of time spent in each sleep phase—stage 1, stage 2, slow wave sleep (SWS), and REM sleep—was recorded.

For the first four days in both sleep phases, the participants ate meals to meet their energy requirements for weight maintenance. On day four, they rated their hunger and level of desire for different foods. On day five, their resting metabolic rate (RMR) was measured, and for the final two days of the sleep phase studies, the participants were allowed to select their own foods.

The researchers then compared the participants' sleep architectures in both the short sleep and habitual sleep conditions. They also analyzed the relationships between sleep architecture, resting metabolic rate, food intake and food desire ratings.

Shechter and his colleagues found that sleep duration is important, but sleep composition—the time and percentage of overall sleep spent in each stage—also plays an important role in the link between sleep and obesity.

Head researcher Shechter explained, “Any number of various factors like obstructive sleep apnea, certain drugs/medications, chronic exposure to short sleep duration, shift work, jet lag, and changes in the scheduling of the sleep episode, can affect sleep stage quantity and distribution. Our data may provide an explanation for the greater obesity prevalence observed within some of these conditions."

Read the full article, “Changes in Sleep Architecture Increase Hunger, Eating.”
The results of this study remind me of another study I blogged about not long ago on “social jetlag,” another reason for all of us to get more sleep.

Social jetlag is a modern 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.

In their study, Professor Roenneberg and his fellow researchers in Munich discovered 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.
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.

So, now that you have this new knowledge about sleep, weight gain, I suggest you give yourself a wonderful personal gift: get more sleep, especially during the holiday season, when many people are overeating and busier than usual. Also spend more time outdoors and exercise. More and better sleep is one of the best gifts you can give yourself for the holidays.

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