Monday, May 23, 2011

Can the Brain Learn to Overcome Sleep Apnea?

New research from the University of Toronto shows that the brain might be more plastic than previously suspected, a quality that will help it overcome the damage inflicted by sleep apnea. The study, published in the December 2010 issue of The Journal of Neuroscience, studied the body's ability to lay down an adaptive respiratory memory.

Researchers studied long-term facilitation of breathing in response to repeated apneic and hypopneic events. In response to these types of events, the body lays down a respiratory memory that that strengthens the ability of respiratory motoneurons to trigger contraction of breathing muscles. In particular, the researchers looked at the effect obstructive sleep apnea had on a number of motoneurons in test rats. In studied rats, the breathing interruptions strengthened muscle tone in the tongue and the muscle that supports it from the chin. Interestingly, this stimulation did not affect the nerves controlling the diaphragm.

This research may help find a drug treatment that can support current forms of sleep apnea treatment. However, the treatment may not be successful if it is not coupled with appropriate positioning of the lower jaw, which supports the tongue. This repositioning of the lower jaw can be accomplished with an oral appliance. With support from a new drug treatment, oral appliance therapy may become the frontline treatment for obstructive sleep apnea even for severe cases. However, since this feedback channel does not stimulate the diaphragm, it may not be a good treatment avenue for central sleep apnea.

To learn more about the sleep apnea treatment options available, please contact a local sleep dentist today.

Saturday, May 21, 2011

Chemical Triggers of Memory Loss

Research published this month in The Journal of Neuroscience has revealed some of the chemical triggers that mediate memory loss related to sleep deprivation. The researchers looked at the role of the nucleoside adenosine in the hippocampus, the center of the brain that directs the function of memory.

Sleep deprivation has long been known to cause an increase in adenosine, an effect common in all animals from arthropods to vertebrates, including humans. Now there is growing evidence that this nucleoside is the source of memory deficits that result from sleep deprivation.

Researchers tested the role of adenosine using two parallel experiments on sleep-deprived mice. In one experiment they used genetically engineered mice that were altered so they could not produce adenosine. In another experiment, researchers used a chemical pump that blocked an adenosine receptor in the hippocampus. Both of these experiments were designed to test whether adenosine was the key factor in sleep deprivation-related memory defects.

In both cases, the mice did not show memory deficits following sleep deprivation. The mice were able to recognize that a box had been moved in their environment, as opposed to the mice without adenosine blocking, who were all unable to identify what part of their environment had been changed from the prior day. These mice also stood up to an electrical measurement of their memory-forming synapses, showing objectively that they were unaffected by the loss of sleep.

In the future it is possible that this research will lead to us blocking the cognitive effects of sleep deprivation, but it is unlikely that it will help prevent some of the physiologic dangers of sleep apnea, such as coronary artery disease (CAD). Avoiding these consequences will still depend on successful sleep apnea treatment.

To learn more about your sleep apnea treatment options, please contact a local sleep dentist today.

Friday, May 20, 2011

Grinding (Bruxism )appliances and Sleep Apnea: Can a grinding appliance make Sleep Apnea Worse? The answer is a definite maybe.

A recent article inthe Journal of Oral Rehabilitation examined the question as to whether a grinding appliance could make sleep apnea aworse. ( of 18 patients showed increases in AHI when their bites were opened without mandibular advancement but only 2 were significantly changed. The article considers whether the vertical opening is responsible for increasing AHI but it is also possible that grinding and/or clenching habits may be protective of the airway and the utilization of these appliances may reduce that activity that is protective against sleep apnea.

It has been previously reported that bruxism appliances can increase sleep apnea in some patients.

J Oral Rehabil. 2011 Apr 5. doi: 10.1111/j.1365-2842.2011.02221.x. [Epub ahead of print]
The effect of raising the bite without mandibular protrusion on obstructive sleep apnoea.
Nikolopoulou M, Naeije M, Aarab G, Hamburger HL, Visscher CM, Lobbezoo F.

Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam (ACTA), Research Institute MOVE, University of Amsterdam and VU University Amsterdam, Amsterdam Department of Clinical Neurophysiology and Center for Sleep-Wake Disorders, Slotervaart Medical Center, Amsterdam, The Netherlands.

Summary  It has recently been suggested that wearing a maxillary occlusal splint (i.e. a hard acrylic resin dental appliance that covers the occlusal surfaces of the maxillary dentition and that is being indicated for the treatment of, e.g. temporomandibular pain) may be associated with a risk of aggravating obstructive sleep apnoea (OSA). The present study tested the hypothesis that raising the bite without mandibular protrusion in OSA patients is associated with an increase in the apnoea-hypopnoea index (AHI). Eighteen OSA patients (13 men; 49·5 ± 8·1 years old) received a mandibular advancement device in 0% protrusion of the mandible (0%MAD). The MAD caused a bite rise of 6 mm as measured interincisally. Polysomnographic recordings were obtained at baseline and with the 0%MAD in situ. No statistically significant difference in AHI was noted between the baseline night and the 0%MAD night. However, nine patients had an aggravation in AHI during the night they used the 0%MAD. Taking into account the previously established smallest detectable difference of 12·8 in AHI, the AHI increased in only two of the patients. The outcomes of this study suggest that an increased jaw gape without mandibular protrusion might be associated with a risk of aggravation of OSA for some, but not for all OSA patients. Dental practitioners should be aware of this possible association when treating patients with oral devices that raise the bite.

© 2011 Blackwell Publishing Ltd.

[PubMed - as supplied by publisher]

Sleep Apnea, Cancer, and Mice

If you suffer from sleep apnea, you are no doubt familiar with the dangers of this condition. The combination of disrupted sleep and lack of oxygen aggravates countless systems in the body and leads to many health problem, one of the most notable being cancer.

We don’t fully understand all the associations between sleep apnea and cancer, but a new study presented yesterday at the ATS 2011 International Conference in Denver has concluded that sleep apnea can speed the growth of cancerous tumors.

Researchers in Spain used two test groups of mice, injecting each group with melanoma cells and monitoring the growth of tumors over a period of 40 days. One group was subject to intermittent hypoxia, or periodic oxygen deprivation meant to simulate obstructive sleep apnea conditions. Since the researchers used mice instead of humans, they were able to make sure that no other conditions, such as heart disease or obesity, affected the data. Intermittent hypoxia was the only variable.

After the 40 days, researchers found that while the tumors grew in both mice groups, the tumor volume was greater in the intermittent hypoxia group, and that these tumors contained greater numbers of dead cells, indicating a more aggressive cancer. This is indeed a frightening finding for sleep apnea sufferers.

Other research on sleep deprivation finds that lack of sleep affects hormones and proteins that play a role in the development of cancer. They also find that sleep deprived people have increased levels of inflammatory indicators, which is a huge risk factor for cancer. The combination of sleep and oxygen deprivation seems to point gravely towards increased risk of cancer and quickly spreading tumors.

If you suffer from sleep apnea, seek contact a local sleep dentist to learn about effective and comfortable sleep apnea treatments.

Monday, May 16, 2011

Sleep Apnea Linked to Incontinence and Erectile Dysfunction

The American Urological Association released research this weekend linking sleep apnea to two different urological disorders: incontinence and erectile dysfunction.

The incontinence study, performed by researchers at the New England Research Institutes, followed 4145 adults--1620 men and 2535 women--for five years. They looked at the incidence of urological conditions and found that restless sleep among men and women was strongly associated with the incidence of urinary tract symptoms. Short sleep duration was also associated for men but not for women.

The other study was conducted by researchers at the Mt. Sinai Medical Center in New York City, and looked more specifically at the link between obstructive sleep apnea and erectile dysfunction. The study looked at men who were being treated for erectile dysfunction. Nearly two-thirds of the men had obstructive sleep apnea, causing researchers to conclude that a man with erectile dysfunction is twice as likely to be a sleep apnea sufferer than the general population.

These studies give additional support to the dangers of sleep apnea, but do not give us insight into new conditions associated with sleep apnea. In the future, it is hoped that further studies will reveal the relationship between successful sleep apnea treatment and alleviating many of these conditions.

To learn more about sleep apnea treatment that is both comfortable and effective, please contact a local sleep dentist today.

Sunday, May 15, 2011

Can Bananas Really Help Your Sleep Apnea?

One of the things you have to understand about sleep apnea information that's available on the Internet is that sometimes stories get passed around with little or no actual research. People are looking to fill up blogs with ideas they think will bring traffic, and may skim through pages and pages of search results in their quest for something to write about. Once one person finds something a little off the beaten path, other people will find it more easily and copy it, often without any critical consideration of the statement.

Consider, for example, the case of bananas and sleep apnea. In late march, one sleep apnea blog reported that bananas could help cure sleep apnea. The next day, another blog reported the same thing, using different words, but offering no additional information. Then in April a couple more blogs pop up touting the benefits of bananas for sleep apnea, and now that we're in May it seems that even more people are promoting this fruit for sleep apnea. It sounds good and rational: eat a banana to improve your sleep apnea. However, is it true?

The source of the story is a 2009 news report on the research of a professor at the University of New England in New South Wales. The research was being reported at a conference in Darwin, and the Northern Territory News outlet covered it. The professor's research showed that phospholipids in bananas could stick to the throat for up to six hours, and that they would reduce surface tension and may help to keep the throat open. In the words of researcher Dr. Tom van der Touw, "Our initial findings suggest that bananas may offer a relatively cheap and tasty alternative as part of the treatment for patients with obstructive sleep apnoea." Although the research was presented at the Thoracic Society of Australia and New Zealand, they do not seem to have panned out in any measurable way. Dr. Van der Touw has not published any further results from the study.

Obstructive sleep apnea is a serious, life-threatening condition, and it's important that you receive effective sleep apnea treatment to avoid an increased risk of stroke, heart attack, and other causes of premature death. Don't listen to folk methods and rumors. Instead, contact a local sleep dentist to learn about effective sleep apnea treatments.