Category: Obstructive Sleep Apnea

Obese adolescents go to bed later and sleep less than their lighter contemporaries. This is the finding of a study published in the April issue of Australian and New Zealand Journal of Public Health.

Professor Tim Olds and his colleagues at the University of South Australia explored the sleep patterns of 9-18 year old Australians on different days of the week. The poor sleep among obese students was particularly evident on Sundays — the night before school resumed after a weekend off.

Other findings that may help parents understand their adolescent children included: * On average, girls slept more, because of earlier bedtimes. * As adolescents grow older, they sleep less. * Underweight children went to bed significantly earlier than those of normal weight.

Prof. Olds said the 'cause and effect' between sleep patterns and weight was unclear.

"The sleep patterns we found sit comfortably with the theory that short sleep duration predisposes towards obesity," he said. "However, there may also be some third factor that contributes to both overweight and short sleep duration."

This third factor may be linked to the time adolescents spend in front of computer or TV screens or low physical activity. "Sleep intervention studies examining the relationship between screen time, weight status and sleep would help to clarify these issues.

— Ben-Gurion University of the Negev (BGU) researchers have shown that a significant number of patients with benign prostate enlargement (BPE) may have Obstructive Sleep Apnea (OSA), which may be the reason for their night awakenings and urination.

This study compared men between the ages of 55 and 75 years-old, who were randomly sampled from primary care clinics, diagnosed with BPE and reported nocturia at least once nightly. The comparison control group had no BPE and one or no nocturia episodes per night.

According to the new study published in the Journal of the American Board of Family Medicine, the BGU researchers found that more than half (57.8 percent) of patients with enlarged prostates may in fact have the sleep disorder, and that the awakenings that patients ascribed to their need to urinate at night may be actually caused by their sleep disorders.

Waking during the night to void, known as "nocturia" is a common BPE symptom. OSA is a sleep disorder characterized by snoring, witnessed apneas, awakenings and day sleepiness.

"If nocturia severity in BPE patients is actually a pre-existing sleep disorder, this can now be treated and help improve patients' quality of life," explains Dr. Howard Tandeter, a researcher in BGU's Department of Family Medicine, Faculty of Health Sciences. He recommends that physicians following patients with BPE who report frequent awakeningsfrom sleep to urinate should suspect OSA as a possible cause and treat accordingly.

"Even among those patients with well-defined medical reasons for nocturia, sleep disorders may still be found as the source of most awakenings from sleep. Therefore, the diagnosis of a sleep disorder should be seriously considered whenever a patient reports frequent awakenings from sleepto urinate since the problem is treatable," explains Tandeter.

Journal Reference:

1. H. Tandeter, S. Gendler, J. Dreiher, A. Tarasiuk. Nocturic Episodes in Patients with Benign Prostatic Enlargement May Suggest the Presence of Obstructive Sleep Apnea. The Journal of the American Board of Family Medicine, 2011; 24 (2): 146 DOI: 10.3122/jabfm.2011.02.100110

NewsPsychology (Feb. 1, 2011) — New research from the University of Toronto could provide some restful nights for the 18 million North Americans who suffer from obstructive sleep apnea.

In a recent study that appeared in the Journal of Neuroscience, scientists from the University demonstrated that repeated obstruction of the airways requires release of the brain chemical noradrenaline. The release of this chemical helps the brain learn to breathe more effectively and purposefully.

“What we showed is that repeated disruption of normal lung activity — what happens during sleep apnea — triggers a form of learning that helps you breathe better. This type of brain plasticity could be harnessed to help overcome the breathing insufficiency that typifies sleep apnea” says Dr. John Peever, Associate Professor of neuroscience and lead author of the study.

In order to mimic the experience of severe sleep apnea, the scientists induced short 15 second apneas in sedated rats by repeatedly restricting airflow into the lungs. They found repeated apneas caused the brain to progressively trigger more forceful contraction of the respiratory muscles, which caused an increase in breathing. This increase in breathing lasted for over an hour.

Peever says it seems the brain is using the unwanted side-effects of sleep apnea to help it learn to prevent future apneas by increasing the depth of breathing.

This study also pinpointed the brain chemical that allows this type of plasticity to occur. They found that noradrenaline is required in the case of repeated apneas to cause brain plasticity and enhance breathing.

These findings are important because they suggest that artificial manipulation with common drugs that affect noradrenaline levels in the brain could also help improve breathing in patients suffering from sleep apnea. This work could serve as the potential basis for developing the long sought after pill for sleep apnea.

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The above story is reprinted (with editorial adaptations by newsPsychology staff) from materials provided by University of Toronto, via EurekAlert!, a service of AAAS.

Journal Reference:

1. A. Tadjalli, J. Duffin, J. Peever. Identification of a Novel Form of Noradrenergic-Dependent Respiratory Motor Plasticity Triggered by Vagal Feedback. Journal of Neuroscience, 2010; 30 (50): 16886 DOI: 10.1523/JNEUROSCI.3394-10.2010

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of NewsPsychology ( or its staff.

 Performing polysomnography (sleep study) prior to pediatric adenotonsillectomy (surgical removal of the tonsils and adenoids) may help identify children at a higher risk of developing postoperative respiratory complications, according to a report in the January issue of Archives of Otolaryngology — Head Neck Surgery, one of the JAMA/Archives journals.

"Pediatric adenotonsillectomy is a safe outpatient procedure; however, there is a subset of patients who do not meet the criteria for outpatient surgery," according to background information in the article. Guidelines for adenotonsillectomy, established by the American Academy of Otolaryngology — Head and Neck Surgery, recommend that children should be healthy, have no evidence of obstructive sleep apnea-hypopnea syndrome (recurring episodes of obstruction or collapse of the upper airway during sleep) and be older than 3 years.

To determine if polysomnography may potentially predict adverse outcomes following a pediatric adenotonsillectomy, Eric M. Jaryszak, M.D., of the George Washington University School of Medicine, Washington, D.C., and colleagues, examined the records of 1,131 children who underwent an adenotonsillectomy by two attending surgeons at an academic pediatric hospital.

Preoperative polysomnography was performed on 151 patients, representing 13.4 percent of all those undergoing adenotonsillectomy. Of these, 23 (15.2 percent) experienced adverse respiratory events after surgery. Results of the polysomnography showed that patients who experienced respiratory complications had significantly higher apnea-hypopnea index (provides an overall severity of sleep apnea including sleep disruptions or low levels of oxygen in the blood), higher hypopnea index (episodes of overly shallow breathing or abnormally low respiratory rates) and lower nadir oxygen saturation (the lowest level of oxygen saturation).

Additionally, the 23 individuals who experienced complications had a higher body mass index (BMI) compared with those who did not have complications, with 47.8 percent defined as obese, according to BMI criteria, versus 29.7 percent in the non-complication subgroup.

Overall, the patients who experienced adverse respiratory events spent an additional 22 days in the hospital beyond routine overnight observation for persons with obstructive sleep apnea-hypopnea syndrome.

"Polysomnographic data may potentially be used for predicting which patients are at higher risk for adverse respiratory events after adenotonsillectomy," the authors conclude. "Such knowledge is valuable in planning postoperative management and perhaps intraoperative anesthesia management."

Journal Reference:

1. E. M. Jaryszak, R. K. Shah, C. C. Vanison, L. Lander, S. S. Choi. Polysomnographic Variables Predictive of Adverse Respiratory Events After Pediatric Adenotonsillectomy. Archives of Otolaryngology – Head and Neck Surgery, 2011; 137 (1): 15 DOI: 10.1001/archoto.2010.226

— In one of the largest studies of its kind Danish sleep researchers from the University of Copenhagen and the Danish Institute for Health Services Research have examined the socio-economic consequences of the sleep disorders snoring, sleep apnea, and obesity-related respiratory difficulties (obesity hypoventilation syndrome (OHS)). These disorders are a serious health and social-economic burden on the individual and on society as a whole.

"Snoring, sleep apnea, and obesity-related respiratory difficulties are fairly common disorders that affect a large proportion of the population," according to Poul Jennum, Professor of Clinical Neurophysiology at the Center for Healthy Ageing at the University of Copenhagen Faculty of Health Sciences. He is head of the Danish Centre for Sleep Medicine, Glostrup Hospital, which treats patients from all over the country.

"Previous studies show that these disorders seriously affect quality of life, and our new studies show that people who snore violently, and particularly those who suffer from sleep apnea, narcolepsy and obesity-related respiratory difficulties, are more frequently in contact with the health service than others; they take more medicine, they are unemployed more often and have lower average incomes than healthy people- The more serious their disorders, the greater the socio-economic costs."

Patients with sleep apnea or obesity-related respiratory difficulties incur medicine and hospital costs two to three times higher than healthy control subjects. The total health costs were twice as high, and unemployment was 30 per cent higher. Patients who suffered from obesity-related respiratory difficulties had the lowest rate of employment. When patients were in work they earned 30 per cent less than healthy control subjects, an indication of lower educational attainment and an effect of the health impact of their disorder.

Every violent snorer costs society €705; the figure for sleep apnea is €3860, while obesity-related respiratory difficulties cost €11 320. These socio-economic consequences are present up to eight years before patients are finally diagnosed with sleep apnea and obesity-related respiratory difficulties. The figures cover direct costs such as more frequent visits to the doctor, hospital admissions or medicine use, and indirect costs by way of lost labour, lower earnings and greater unemployment. The researchers also noted that the patients were more likely to be on welfare than healthy subjects, and more likely to be on prescription medicines subsidised by the state.

In addition to these costs there are also the actual costs of welfare payments. Patients who suffer from snoring, sleep apnea or obesity-related respiratory difficulties received an average of €147, €879 and €3263 in extra welfare payments.

"Our study is the first to look at the actual socio-economic cost of the three disorders," Professor Jennum continues. In the last couple of years he has conducted several studies into the socio-economic costs of sleep disorders such as narcolepsy, where researchers found higher medicine consumption, more hospital admissions, and 30 per cent greater unemployment when the disease was undiagnosed and untreated. So there is plenty of potential for ensuring earlier intervention, diagnosis and therapy.

"In the last few years we have become better at diagnosing and treating sleep apnea and obesity-related respiratory difficulties. This may help our patients, because we know that there are lots and lots of people out there who are terribly tired in the daytime without being diagnosed and without knowing why. If you sleep badly at night for long periods at a time this may be due to various sleeping disorders, most of which we can treat nowadays. So it is important for people with sleep disorders to get in touch with the health service; otherwise their health, education, ability to work, and thereby their finances may be affected."

The study was published Jan. 2, 2011 in Thorax: An international Journal Of Respiratory Medicine.

Journal Reference:

1. P. Jennum, J. Kjellberg. Health, social and economical consequences of sleep-disordered breathing: a controlled national study. Thorax, 2011; DOI: 10.1136/thx.2010.143958

Patients with obstructive sleep apnea often report that they feel like "a new person" after beginning treatment with continuous positive airway pressure therapy. A new study in the Jan. 1 issue of the journal Sleep provides objective evidence to support these anecdotal reports, showing that three weeks of CPAP therapy significantly reduced fatigue and increased energy in patients with OSA.

Results of the randomized controlled trial show that CPAP therapy significantly reduced self-reported, mean fatigue scores on two independent measures: from 8.76 at baseline to -0.10 post-treatment on the Multidimensional Fatigue Symptom Inventory — Short Form; and from 7.17 at baseline to 4.03 post-treatment on the fatigue-inertia subscale of the Profile of Mood States — Short Form. These results indicate that participants were no longer suffering from clinically significant levels of fatigue after the three-week intervention period.

Self-reported energy levels also increased after three weeks of CPAP therapy, with the mean score on the vigor-activity subscale of the Profile of Mood States — Short Form increasing significantly from 14.28 at baseline to 16.52 post-treatment. Significant changes in fatigue and energy were not observed in participants who received placebo CPAP.

"This was one of the first double-blind studies of the effects of CPAP on fatigue," said lead author Lianne Tomfohr, graduate research assistant in the joint doctoral program at San Diego State University and the University of California, San Diego. "These results are important, as they highlight that patients who comply with CPAP therapy can find relief from fatigue and experience increases in energy and vigor after a relatively short treatment period."

Further analysis found that CPAP appeared to be especially beneficial for participants who were excessively fatigued or sleepy before treatment. CPAP therapy significantly reduced self-reported daytime sleepiness in this group, with their mean score on the Epworth Sleepiness Scale dropping from 13.0 at baseline to 8.9 post-treatment.

According to the American Academy of Sleep Medicine, OSA is a common sleep-related breathing disorder that affects at least two to four percent of the adult population. OSA occurs when the muscles relax during sleep, causing soft tissue in the back of the throat to collapse and block the upper airway. Most people with OSA snore loudly and frequently, and they often experience fatigue and excessive daytime sleepiness.

The treatment of choice for OSA is CPAP therapy, which provides a steady stream of air through a mask that is worn during sleep. This airflow keeps the airway open to prevent pauses in breathing and restore normal oxygen levels.

Tomfohr and a team of UCSD researchers studied 59 adults with a mean age of 48 years. Overnight polysomnography in a sleep lab confirmed that each participant had OSA, which was defined as having an apnea-hypopnea index (AHI) of 10 or more partial reductions (hypopneas) and complete pauses (apneas) in breathing per hour of sleep.

Participants were randomly assigned to receive either therapeutic CPAP or placebo CPAP, and they returned to the sleep lab for a night of either CPAP titration or mock titration. Participants were trained on the use of the equipment and instructed to use it at home each night for three weeks. Questionnaire data were obtained prior to study randomization and after the three-week intervention period.

According to the authors, the mechanisms that underlie the observed changes in fatigue are unclear. They speculate that CPAP may impact fatigue in patients with OSA by reducing inflammation, noting that increases in inflammatory markers in OSA patients have been related to elevated fatigue.

The study was supported by the National Institutes of Health through the National Heart, Lung, and Blood Institute; National Institute on Aging; and National Center for Research Resources.

Journal Reference:

1. Tomfohr LM; Ancoli-Israel S; Loredo JS; Dimsdale JE. Effects of continuous positive airway pressure on fatigue and sleepiness in patients with obstructive sleep apnea: data from a randomized controlled trial. Sleep, 2011;34(1):121-126 [link]

A study in the Dec. 1 issue of the journal Sleep found that loud snoring and two common insomnia symptoms — difficulty falling asleep and unrefreshing sleep — each significantly predicted the development of the metabolic syndrome. The study emphasizes the importance of screening for common sleep complaints in routine clinical practice.

Results of multivariate logistic regression models show that the risk of developing the metabolic syndrome over a three-year follow-up period was more than two times higher in adults who reported frequent loud snoring (odds ratio = 2.30). This risk also was increased by 80 percent in adults who reported having difficulty falling asleep (OR = 1.81) and by 70 percent in those who reported that their sleep was unrefreshing (OR = 1.71).

Further analysis found that unrefreshing sleep was reduced to marginal significance with additional adjustment for loud snoring. However, when simultaneously entered in a statistical model, both loud snoring and difficulty falling asleep remained significant independent predictors of the metabolic syndrome.

"This is the first prospective study to show that a broader array of commonly reported sleep symptoms, including insomnia and sleep-disordered breathing symptoms, predict the development of the metabolic syndrome, a key risk factor for cardiovascular disease," said lead author Wendy M. Troxel, PhD, assistant professor of psychiatry and psychology at the University of Pittsburgh in Pittsburgh, Pa. "It was rather striking that the effects of difficulty falling asleep and loud snoring were largely independent of one another."

According to the National Heart, Lung, and Blood Institute, metabolic syndrome is a group of obesity-related risk factors that increases an individual's risk of heart disease, diabetes and stroke. A person with at least three of these five risk factors is considered to have metabolic syndrome: excess abdominal fat, high triglycerides, low HDL cholesterol, high blood pressure and high blood sugar.

Analyses of these five individual components of the metabolic syndrome revealed that loud snoring significantly predicted the development of high blood sugar (OR = 2.15) and low HDL cholesterol (1.92). Difficulty falling asleep and unrefreshing sleep did not predict any of the individual metabolic abnormalities.

Only loud snoring continued to predict the development of the metabolic syndrome after accounting for the number of metabolic abnormalities present at baseline. According to the authors, this suggests that loud snoring may be a causal risk factor cardiometabolic dysregulation.

The study involved 812 participants in Heart SCORE, an ongoing, community-based, prospective study of adults between 45 and 74 years of age. People who were classified as having the metabolic syndrome or diabetes at baseline were excluded form the study. During the three-year follow-up period, 14 percent of participants developed the metabolic syndrome.

Self-reported sleep disturbances were assessed using the Insomnia Symptom Questionnaire and the Multivariable Apnea Prediction Questionnaire. The development of the metabolic syndrome was unrelated to difficulty staying asleep and frequent awakening from sleep, which are two other insomnia symptoms that are commonly reported.

Apnea-hypopnea index (AHI), an average of the combined episodes of partial reductions (hypopneas) and complete pauses (apneas) in breathing per hour of sleep, was calculated in a subset of 290 participants who wore a portable monitor that measured nasal airflow. In an analysis of this subset, loud snoring remained an independent predictor of the development of the metabolic syndrome (OR = 3.01) even after adjusting for AHI, while difficulty falling asleep was reduced to marginal statistical significance.

More information about snoring is available from the American Academy of Sleep Medicine at http://www.sleepeducation.com/Disorder.aspx?id=26.

The study was supported by the Commonwealth of Pennsylvania Department of Health; and the National Heart, Lung, and Blood Institute and the Clinical & Translational Science Awards of the National Institutes of Health.

Journal Reference:

1. Troxel WM; Buysse DJ; Matthews KA; Kip KE; Strollo PJ; Hall M; Drumheller O; Reis SE. Sleep symptoms predict the development of the metabolic syndrome. Sleep, 2010; 33 (12): 1633-1640 [link]

A new study, derived from novel sleep research conducted by University of California, San Diego researchers 14 years earlier, suggests that the secret to a long life may come with just enough sleep. Less than five hours a night is probably not enough; eight hours is probably too much.

A team of scientists, headed by Daniel F. Kripke, MD, professor emeritus of psychiatry at UC San Diego School of Medicine, revisited original research conducted between 1995 and 1999. In that earlier study, part of the Women's Health Initiative, Kripke and colleagues had monitored 459 women living in San Diego (ranging in age from 50 to 81) to determine if sleep duration could be associated with mortality.

Fourteen years later, they returned to see who was still alive and well.

Of the original participants, 444 were located and evaluated. Eighty-six women had died. Previous studies, based upon questionnaires of people's sleep habits, had posited that sleeping 6.5 to 7.5 hours per night was associated with best survival. Kripke and colleagues, whose 1990s research had used wrist activity monitors to record sleep durations, essentially confirmed those findings, but with a twist.

"The surprise was that when sleep was measured objectively, the best survival was observed among women who slept 5 to 6.5 hours," Kripke said. "Women who slept less than five hours a night or more than 6.5 hours were less likely to be alive at the 14-year follow-up."

The findings are published online in the journal Sleep Medicine.

Kripke said the study should allay some people's fears that they're not getting enough sleep. "This means that women who sleep as little as five to six-and-a-half hours have nothing to worry about since that amount of sleep is evidently consistent with excellent survival. That is actually about the average measured sleep duration for San Diego women."

Researchers uncovered other interesting findings as well. For example, among older women, obstructive sleep apnea (pauses in breathing during sleep) did not predict increased mortality risk. "Although apneas may be associated with increased mortality risk among those under 60, it does not seem to carry a risk in the older age group, particularly for women," Kripke said.

Co-authors of the study include Robert D. Langer of the Jackson Hole Center for Preventive Medicine; Jeffrey A. Elliot and Katharine M. Rex of the UCSD Department of Psychiatry; and Melville R. Klauber of the UCSD Department of Family and Preventive Medicine.

 Continuous positive airway pressure therapy helps restore memory consolidation in adults with obstructive sleep apnea, suggests a research abstract presented June 9, 2010, in San Antonio, Texas, at SLEEP 2010, the 24^th annual meeting of the Associated Professional Sleep Societies LLC.

Results indicate that OSA patients being treated with CPAP therapy outperformed untreated OSA patients on an overnight picture memory consolidation task, suggesting that CPAP is effective at recouping memory abilities that are impaired by OSA. CPAP patients correctly identified more photographs after one night of sleep.

"The most surprising result of our study, thus far, is the noticeable improvement in memory that CPAP patients experience," said lead author Ammar Tahir of the Memory Laboratory in the department of psychology at the University of Notre Dame in South Bend, Ind. "These results suggest the success of CPAP therapy in regenerating obstructive sleep apnea patients' memory deficits."

The researchers also made the intriguing discovery that OSA patients who were using CPAP therapy performed better on the memory task than a control group of people who did not have OSA. This important finding could provide direction for future research to study the effect of CPAP therapy on brain function and memory processes.

The study involved a preliminary sample of 135 adults between the ages of 33 and 65 years who were divided into three groups. The experimental group comprised 78 people who were diagnosed with OSA and had been using CPAP therapy for three or more weeks. The baseline group was composed of 50 people who were diagnosed with OSA but had not been using CPAP. The control group had 30 people who tested negative for OSA. Data from additional participants in this ongoing study were not yet available when the abstract was published.

All participants were shown 20 photographs the night before their sleep was monitored by in-lab polysomnography. The next morning they were presented with 20 pairs of photographs. Each pair contained one photo that had been presented the previous night and one similar but previously unseen image. Participants had to determine which photo in each pair was the one that they had already viewed.

The American Academy of Sleep Medicine reports that OSA is a sleep-related breathing disorder that involves a decrease or complete halt in airflow despite an ongoing effort to breathe. It occurs when the muscles relax during sleep, causing soft tissue in the back of the throat to collapse and block the upper airway. This leads to partial reductions (hypopneas) and complete pauses (apneas) in breathing that can produce abrupt reductions in blood oxygen saturation and reduce blood flow to the brain. Most people with OSA snore loudly and frequently, and they often experience excessive daytime sleepiness.

The treatment of choice for OSA is CPAP therapy, which provides a steady stream of air through a mask that is worn during sleep. This airflow keeps the airway open to prevent pauses in breathing and restore normal oxygen levels. Help for OSA is available at more than 2,000 AASM-accredited sleep disorders centers across the U.S.