The Insomnia Blog - Sleep Doctor Michael Breus, PhD

Sleep apnea linked to cancer

2012-06-04T09:51:41-07:00

We’ve known for some time that obstructive sleep apnea (OSA) is associated with a number of serious health problems, including cardiovascular disease and diabetes. Now, for the first time, two separate
studies have found a link between sleep apnea and cancer in humans. This news made big headlines recently—with good reason.

The results of these studies were both presented recently at an American Thoracic Society conference. These two studies are the first to establish a link between OSA and cancer in humans. Previous studies have shown evidence of a relationship between cancer and sleep apnea in mice.

In one study, conducted at the University of Wisconsin School of Public Health and Medicine, researchers used data from a long-term, extensive sleep study to investigate a possible relationship between obstructive sleep apnea and cancer deaths. The Wisconsin Sleep Cohort Study has compiled 22 years of data on sleep and health for 1,522 men and women, including periodic overnight sleep analysis using polysomnography, a measurement of sleep and breathing. Researchers made
adjustments to their analysis to account for other factors that could affect cancer risk, including age, gender, weight, and smoking. Among the participants in the Sleep Cohort Study, researchers found:

The presence of mild sleep apnea was associated with a 10% increase in death from cancer
Moderate sleep apnea was associated with a doubling of the risk of cancer death
Severe sleep apnea was associated with a nearly five-fold increase in death from cancer

In the second study, conducted at the Hospital General de Requena in Valencia, Spain, researchers
analyzed data from 5,246 patients who where treated for possible sleep apnea between the years 2000-2007. The researchers also adjusted for other genetic and lifestyle factors that influence cancer risk. They found that severe OSA was associated with a 65% higher risk of developing cancer.

These two studies mark the first time that sleep apnea and cancer have been linked in humans. But previous studies have found this link in animals. Researchers at the University of Barcelona investigated the link between OSA and cancer in mice. They found what when mice with melanoma were deprived of oxygen periodically, their melanoma tumors grew more quickly than mice that were not deprived of oxygen.

This kind of periodic oxygen deprivation—known as hypoxia—is the fundamental characteristic of obstructive sleep apnea. When a person has OSA, his or her airway collapses during sleep, depriving the body of oxygen for a short period of time. Breathing is interrupted, and the levels of oxygen in the blood drop. The severity of sleep apnea is determined by how frequently these periods of interrupted breathing occur. Mild sleep apnea is generally regarded as 5-15 breathing interruptions per hour of sleep, while moderate sleep apnea is measured at 15-30 interruptions per hour of sleep. Severe sleep apnea is considered anything over 30 periods of interrupted breathing per hour of sleep.

It is important to note that neither study established sleep apnea as a direct cause of developing
cancer or dying from cancer. What each of these studies did is establish an association between the presence and severity of sleep apnea, and the risk of both developing and dying from cancer. These studies represent an important breakthrough in our understanding of the effects of sleep apnea and oxygen deprivation during sleep. They are a significant first step, and additional research will—and should—undoubtedly follow.

These studies also contribute to the growing body of knowledge that sleep apnea, left untreated, is dangerous and damaging to health. Before this latest cancer news, sleep apnea was already associated with several serious health problems, including:

Stroke: This study found sleep apnea present in 91% of stroke patients who were evaluated for the
sleep disorder.

Heart disease: We’ve known for some time about a strong association between sleep apnea and heart
problems. Sleep apnea is common among patients with high blood pressure, atrial fibrillation, and heart disease. In this study, men with severe obstructive sleep apnea were 68% more likely to develop coronary disease and 58% more likely to develop heart failure, than men without OSA.

Diabetes: This new study found that low oxygen levels in the blood—a result of OSA—are associated with elevated blood sugar, and that sleep apnea is a predictor for Type 2 diabetes.

More than 18 million Americans suffer from obstructive sleep apnea, according to the National Sleep Foundation. Many more are likely undiagnosed, and therefore going without important treatment. What’s more: sleep apnea and sleep disordered breathing don’t just affect adults. Children also are at risk for this sleep disorder, and the other health risks that come with it.

Do you need a better reason to pay attention to your sleep, and your family’s sleep?

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™

www.thesleepdoctor.com

The Sleep Doctor’s Diet Plan: Lose Weight Through Better Sleep

Everything you do, you do better with a good night’s sleep™

twitter: @thesleepdoctor

Facebook: www.facebook.com/thesleepdoctor

Sleeping gives memory and learning a lift

2012-05-31T09:17:45-07:00

Want to maximize your learning capacity? Get some sleep. That’s the takeaway from a study that examined the influence of sleep and time of day on learning and memory. This latest research is another piece of compelling evidence that sleeping helps to strengthen our ability to learn new things, and to convert new learning into longer-term memories.

In this study, 207 students who slept regularly for at least 6 hours per night were assigned to learn two different sets of word pairs. One set of word pairs were semantically related; the other pairs were made up of unrelated words. The difference is important. The type of learning involved in recalling unrelated word pairs is different than for pairs that are related, and involves forming new associations, essentially creating a relationship in the mind for these words that are otherwise un-related.

The students were assigned to study the word pairs at one of two times: 9 a.m. or 9 p.m. After an initial study period to learn the two types of word pairs, the students were re-tested after 30 minutes, then again after 12 hours, and a final time after 24 hours. The students who did their learning in the evening went to sleep for their regular nightly rest relatively soon after their initial study period. The daytime learning students, on the other hand, spent a normal day of wakefulness before going to bed as usual that evening.

This allowed researchers to assess the influence of time of day on learning. It also allowed them to examine how the proximity of sleep to learning might have an influence.

What did they find?

Time of day had no effect on performance and initial memory (at the 30 minute test). This was true for both types of word pairs.
After 12 hours, overall memory was better after a night’s sleep than for those who spent the day awake
After 24 hours, researchers found that students who went to sleep shortly after learning had better memory of what they learned than those who did their learning followed by a day of wakefulness before sleep.
The different types of word pairs—and the two types of learning they required—fared differently depending on sleep. Memory for related word pairs was not affected by how soon sleep followed learning. Memory for the un-related word pairs—the kind that required making new associations—was stronger for students who slept shortly after learning than for those who spent the day awake.
The deterioration of memory during the wake period was less when students had slept shortly after learning

These results indicate that sleep is most helpful to memory when it happens soon after learning new things. Sleep seems to have a stabilizing effect on newly learned information, rooting it into memories that last and clearing the way for new information to be processed.

This latest research joins a series of recent breakthroughs in the study of sleep and memory.

In this study, researchers used fruit flies to test the links between sleep and the creation of long-term memories. After breeding fruit flies to sleep on demand, researchers exposed the flies to new information. All of the flies retained their new knowledge for a short period of time, but only the flies that slept after learning appeared to convert their short-term knowledge to long-term memory.
Another study showed how sounds heard during sleep may help to direct and enhance memory. Participants learned a spatial puzzle that involved moving images to specific places on a computer screen. While doing this, they heard sounds that corresponded to specific images. During sleep, the study subjects were exposed to half of those same sounds. When they performed the puzzle again from memory after sleeping, they were better able to recall the placement of images whose sounds they’d heard during sleep.
This study showed how naps can boost brain power. Two groups of young adults learned the same task. One group napped after learning; the other didn’t. Six hours after learning the initial task, both groups were asked to learn brand new material. The non-napping group scored lower than they had on their initial learning exercise, while the napping group actually improved their performance compared to their first one.

Sleep doesn’t only enhance memory. It also appears to diminish the emotional impact of painful
memories. In a study I wrote about recently, two groups were exposed to emotionally charged images. Both groups saw the images twice, in viewings twelve hours apart. One group slept in between viewings and the other did not. Those who slept reported feeling less of an emotional reaction to the images at their second viewing, compared to the group who did not sleep. MRI scans showed decreased activity in the region of the brain that processes emotions for the group who slept.

We’re learning more all the time about how sleep helps us learn and retain information, how it clears the mind and prepares us to learn new things, as well as how it may protect us from the emotional pain of
difficult memories.

Whether you’re prepping for a test, starting a new job, coping with difficult circumstances, or just want to feel more agile of mind, the prescription is the same: get some sleep!

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™

www.thesleepdoctor.com

The Sleep Doctor’s Diet Plan: Lose Weight Through Better Sleep

Everything you do, you do better with a good night’s sleep™

twitter: @thesleepdoctor

Facebook: www.facebook.com/thesleepdoctor

Energy drinks elevate blood pressure

2012-05-08T08:07:19-07:00

Those fun, harmless-looking energy drinks in the colorful bottles that you see everywhere these days? Those beverages with “natural” ingredients, marketed to all of us—especially our kids—as an alternative to soda? Turns out these drinks aren’t so harmless.

Concerns about the effects of energy drinks are continuing to grow, as new research shows these drinks can cause blood pressure to rise, as well as bringing about heart palpitations and arrhythmias, anxiety, and insomnia.

Researchers in Poland conducted a small study with 18 healthy young adults ages 20-35. The young adults were asked to consume one of two energy drinks: one contained 120 mg of caffeine and the other contained 360 mg of caffeine. (A regular 8-ounce cup of brewed coffee has between 100-200 mg of caffeine.) A third group drank a placebo, which contained no caffeine or other stimulants. Researchers then took measurements of blood pressure and heart rate at 15, 30 and 90 minutes after consumption.

They found that the less caffeinated drink did not significantly affect either blood pressure or heart rate, compared with the placebo group. The more highly caffeinated drink, on the other hand, had a significant effect on both. Among those who consumed the 360 mg caffeine energy drink:

Blood pressure went up by an average of 9 points, for both systolic and diastolic pressure.
Heart rate went up by an average of 5 beats per minute.
Members of this group also developed irregular heartbeats, racing heartbeats, anxiety
and insomnia.

This study isn’t the first to find a link between high-caffeine, high-sugar energy drinks and elevated blood pressure, cardiac disturbances, anxiety and sleep disturbances. Other recent research has returned similarly disturbing results:

A study conducted at the University of Arkansas examined the effects of energy drinks on blood pressure, among health, non-smoking adults ages 18-45. The results reported blood pressure was
significantly elevated in those who drank one serving of Red Bull, which contained 80 mg of caffeine, and 1000 mg of taurine, an amino acid commonly found in energy drinks.

An Australian research project collected information about the health hazards of energy drinks by analyzing data associated with consumption of energy drinks and calls to a poison information hotline. Between 2004 and 2010, the poison hotline took a total of 297 phone calls from people who reported having consumed energy drinks.

Over the 6-year study period, the number of calls per year increased significantly, from 12 in 2004 to 65 in 2010.
100 callers also reported consuming other substances along with the energy drinks, most often alcohol or another product containing caffeine.
87% of those who called reported some type of symptom. Common symptoms were palpitations, feelings of agitation, tremors, and upset stomachs.
7% of callers reported more serious symptoms, including hallucinations, seizures and irregular heartbeats.
Of the 297 callers, 128 were hospitalized. This included 57 people who only consumed energy drinks, without other substances such as alcohol or additional caffeine.
The median age of the callers was 17 years old.

At the University of Massachusetts, a review of research related to the health complications from energy drinks found frequent reports of adverse affects among adolescents, and concluded that the health concerns posed called for “urgent research on the safety of energy drinks in children
and adolescents.”

We’re still in the early days of learning about the full range of effects of these drinks on physical and mental health, as well as sleep. There is an abundance of research that shows how too much caffeine can affect blood pressure and heart rate, create anxiety, and disrupt sleep. We know much less about the short and long-term effects of some of the other ingredients that are often found in energy drinks, including taurine, the vitamins niacin and pyridoxine, and sugars such as inositol.

Here’s what is clear. People who have or are at risk for conditions such as heart disease, hypertension, and diabetes need to strictly limit—or better yet avoid altogether—these energy drinks. Parents need to educate their kids about the serious risks of over-consumption of energy drinks, and to closely monitor their children’s consumption, if they choose to allow them to have these drinks at all. Unfortunately, kids and teenagers are among the most likely consumers of these beverages. Energy drinks are heavily marketed to young people, who are less likely to be aware of the possible dangers of these beverages.

It’s also time for the Food and Drug Administration (FDA) to get involved, and for these drinks to be subjected to greater regulation, including regulating the amount of caffeine that can be included in a single serving. Historically, energy drinks have been classified—and marketed—as dietary supplements, which are subject to only the most minimal regulation. Canada recently re-classified energy drinks as foods, opening them up to more comprehensive regulation. It’s time for a serious look by the FDA at doing the same thing in the US.

Do you rely on energy drinks to pep yourself up in the morning, to power you through the day, to avoid a mid-afternoon slump in energy? If so, there are better—and safer—ways to stay alert. Some even involve caffeine—just moderate amounts.

Start with a cup of coffee in the morning. Morning exercise is also a great energy booster.
To avoid the midday slump: try eating a high-protein snack. Think small serving of cheese with some fruit, or peanut butter on crackers or whole grain toast. This will boost your energy without making you feel too full or sluggish.
If you’re really dragging, try my Nap-a-Latte™ technique: Drink a small cup of coffee and follow it up with a 25-minute nap. The combination will curb drowsiness without overdoing it on the caffeine and risking disruption to your nighttime sleep. Make sure to do this before 3pm.

Best tip of all? Get a good night’s sleep! Its one of the very best things you can do to avoid daytime fatigue and protect your overall health.

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™

www.thesleepdoctor.com

The Sleep Doctor’s Diet Plan: Lose Weight Through Better Sleep

Everything you do, you do better with a good night’s sleep™

twitter: @thesleepdoctor

Facebook: www.facebook.com/thesleepdoctor