Primary care can effectively manage obstructive sleep apnea

Primary care management of obstructive sleep apnea (OSA) is as effective and more cost-effective than in-laboratory diagnosis, according to a study published online April 17 in the American Journal of Respiratory and Critical Care Medicine.

02 may 2018--M. Ángeles Sánchez-Quiroga, M.D., from Virgen del Puerto Hospital in Madrid, and colleagues randomized 303 sequentially screened patients with an intermediate-to-high probability of OSA to primary care management (a portable monitor with automatic scoring and semi-automatic therapeutic decision-making) or in-laboratory management (polysomnography and specialized therapeutic decision-making). All patients received continuous positive airway pressure treatment or sleep hygiene and dietary treatment alone.
The researchers found that the primary care protocol was noninferior to the in-laboratory protocol based on use of the Epworth sleepiness scale. Furthermore, primary health care management was more cost-effective, with a lower cost of €537.8 per patient.
"Primary health care area management may be an alternative to in-laboratory management for patients with an intermediate to high OSA probability," the authors write. "Given the clear economic advantage of outpatient management, this finding could change established clinical practice."

More information: Abstract/Full Text (subscription or payment may be required)

Daytime impairments in older men with obstructive sleep apnea are related to total sleep time

This study is the first to evaluate the extent to which any associations between obstructive sleep apnea severity and daytime functional impairments were confounded by short sleep duration in a population-based sample of older men

Westchester, Ill., 01 feb 2009— A study in the Feb. 1 issue of the journal SLEEP shows that daytime functional impairments in older men with obstructive sleep apnea (OSA) are largely explained by total sleep time rather than OSA severity.

A modest link between OSA severity and daytime sleepiness, measured by the Epworth Sleepiness Scale, was no longer statistically significant after controlling for total sleep time. Neither sleep disturbances, measured by the Pittsburgh Sleep Quality Index, nor sleep-related quality of life, measure by the Functional Outcome of Sleep Questionnaire, were associated with OSA severity; all three measures were modestly associated with total sleep time.

According to lead author Dr. Eric J. Kezirian, director of the division of sleep surgery in the department of otolaryngology at the University of California in San Francisco, the study shows that the functional consequences of OSA in older men may differ from those in younger populations and may need to be measured with instruments designed specifically for the demographic.

"While the disorder is associated with behavioral and health-related effects that improve with treatment in young and middle-aged adults, there is little evidence concerning its adverse consequences or treatment benefits in older adults," said Kezirian. "This study showed that in a community-dwelling group of older men, the severity of OSA was not associated with daytime sleepiness, sleep symptoms, or sleep-related quality of life, after controlling for sleep duration."

Data were collected from 2,849 men with a mean age of 76.4 years. Thirteen percent (365/2849) of participants had an ESS of at least 10, a level commonly considered to be excessive sleepiness. The presence and severity of OSA were measured by in-home polysomnography. Overall the study group demonstrated mild to moderate OSA with an average apnea-hypopnea index (AHI) of 17.0. Forty-three percent had an AHI of 15 or more.

Average total sleep time was measured by actigraphy over multiple nights. Thirty-one percent (889/2849) had a short sleep time of less than 360 minutes per night, and the prevalence of short sleep time increased with AHI. Individuals with higher AHI levels also were slightly older than men with lower AHI levels, and they had a higher body mass index, poorer self-reported health status and a higher Geriatric Depression Scale score.

Keizirian said that having a better understanding of OSA in older adults will help medical professionals treat the condition more effectively.

According to the American Academy of Sleep Medicine, 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. Brief arousals from sleep restore normal breathing but can cause a fragmented quality of sleep. Most people with sleep apnea snore loudly and frequently, and they often experience excessive daytime sleepiness.

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More information about OSA is available from the AASM at http://www.sleepeducation.com/Disorder.aspx?id=7.

SLEEP is the official journal of the Associated Professional Sleep Societies, LLC (APSS), a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS publishes original findings in areas pertaining to sleep and circadian rhythms. SLEEP, a peer-reviewed scientific and medical journal, publishes 12 regular issues and 1 issue comprised of the abstracts presented at the SLEEP Meeting of the APSS.

For a copy of the study, "Behavioral Correlates of Sleep-Disordered Breathing in Older Men," or to arrange an interview with the study's author, please contact Kelly Wagner, >AASM public relations coordinator, at (708) 492-0930, ext. 9331, or kwagner@aasmnet.org.

Sleep disordered breathing and obesity: independent effects, causes

Sleep Apnea Linked to Insulin Resistance, Independent of Obesity

27 jan 2009--In a study that addressed the issue of insulin sensitivity with respect to sleep disordered breathing (SDB), Naresh Punjabi, M.D., Ph.D. sought to examine the relationship between SDB and insulin resistance using the best tools at his disposal to do so.

The results definitively link SDB to pre-diabetic changes in insulin production and glucose metabolism. It was published in the first issue for February of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

"In the past researchers have used body mass index, or BMI, as a proxy measure for body fat, but we know this to be a variable and crude tool to assess the true percentage of body fat," said Dr. Punjabi. "In addition, previous studies have used surrogate measurements to assess the body's response to insulin without investigating the interaction that occurs between reduced insulin sensitivity and increased insulin production in the body."

To address the shortcomings of previous studies, Dr. Punjabi and colleagues used two tools in their investigation into the link between SDB and insulin resistance: dual-energy x-ray absorptiometry (DEXA), a highly precise technique for assessing body fat, and frequently sampled intravenous glucose tolerance test (FSIVGTT), which provides a detailed picture of the subject's insulin sensitivity over time, rather than a simple snapshot at a specific moment.

They recruited 118 subjects, 39 who had no SDB, and 79 who were newly diagnosed with SDB but who had not been treated. Each subject underwent a sleep study to assess their level of SDB, and then underwent a FSIVGGT to determine their glucose metabolism and insulin sensitivity/production the following day.

"Our major finding was that, as we suspected, SDB was strongly associated with a decrease in the three major metabolic pathways that the body uses to metabolize glucose— insulin sensitivity, glucose effectiveness, and pancreatic cell function— independent of adiposity," said Dr. Punjabi. "What our research tells us is that SDB is characterized by multiple physiological deficits that increase the predisposition for type 2 diabetes mellitus."

Sleep Apnea linked to the Progression of Liver Disease

In another study published in the same issue of the Journal, other researchers from Johns Hopkins Bayview Medical Center Bariatric Surgery Clinic found that the chronic intermittent hypoxia that often characterizes OSA, a common form of SDB, is also independently linked to the progression of liver disease.

In this study, researchers recruited 90 severely obese patients presenting for bariatric surgery at without known diagnoses of obstructive sleep apnea. Each patient underwent a sleep study and blood tests for markers of liver function, insulin resistance, and systemic inflammation. And, because standard practice for patients undergoing bariatric surgery is to biopsy the liver, the researchers were able to analyze liver tissue for signs of disease and link it to the severity and type of sleep disordered breathing they observed during the sleep study.

The results validated the link between OSA and insulin resistance, and further linked it to the level of hypoxemia experienced during the night versus simply the number of apneic events. Strikingly, of the patients whose liver tissue was analyzed, those who were observed to have severe nocturnal hypoxemia also exhibited "ballooning" of their hepatocytes and a pericellular fibrosis of the liver, indicating liver injury.

"We demonstrated that the severity of nocturnal oxyhemoglobin desaturation predicted the severity of insulin resistance and might be implicated in the development of liver disease. In contrast, severe obesity was associated with high levels of serum c-reactive protein (CRP), indicating systemic inflammation," said lead researcher, Vsevolod Y. Polotsky, M.D., Ph.D., of Johns Hopkins' Asthma and Allergy Center. "Interestingly, there was no relationship between the severity of nocturnal hypoxemia and serum CRP. This suggests that that obesity and OSA have distinct metabolic, inflammatory and hepatic profiles, which act in different detrimental ways on the liver."

"We hypothesize that severe obesity per se acts as a 'first hit' in the progression of liver disease, inducing hepatic steatosis, whereas the presence of the chronic intermittent hypoxemia that often characterizes OSA acts as a 'second hit'. The hypoxic stress of OSA may induce oxidative stress in the livers of patients with severe obesity, leading to further inflammation."

The clinical implications of the findings are clear: obesity and obstructive sleep apnea exert separate and perhaps additive negative effects on insulin resistance and the liver, and each disorder must be treated concomitantly in order to address the secondary complications.

"Our data suggest that patients with OSA and severe nocturnal hypoxemia should be screened for liver disease and, conversely, patients with liver disease should be screened for OSA," said Dr. Polotsky.

"We have developed a mouse model of intermittent hypoxia and have demonstrated that a combination of a high-fat diet and intermittent hypoxia leads to liver disease in those mice. We plan on continuing to use the model in future research. We plan to examine whether treatment of OSA with continuous positive airway pressure can improve or reverse liver disease."

Severity of OSA Linked to Sedentary Lifestyle

Not only is OSA linked to insulin resistance and liver disease independent of obesity, but at least one risk factor is also common to obesity and OSA: prolonged daytime sitting or standing. Even when the sedentary lifestyle does not lead to obesity, it may still lead to OSA and its concomitant health risks, according to another research article in the first issue for February of the American Journal of Respiratory and Critical Care Medicine.

"Overnight fluid displacement from legs, related to prolonged sitting, may play a previously unrecognized role in the pathogenesis of OSA," wrote principle investigator, T. Douglass Bradley, M.D., professor of medicine and director of the Centre for Sleep Medicine and Circadian Biology at the University of Toronto,

The research also found that the volume of fluid shift was directly linked to the hours in a day that the subject reported sitting or standing and was independent of the excess weight that often accompanies sedentary lifestyles.

"In more recent years, the introduction of modern technologies into the workplace has greatly reduced the need for physical activity and increased the number of jobs requiring prolonged sitting, during which absence of the contraction of calf muscles leads to dependent fluid accumulation in the legs that is proportional to the time spent in that position," explained Dr. Bradley. "When assuming the recumbent position at bedtime, the fluid retained in the legs during the day in redistributed to the upper body. It is therefore plausible that some of the displaced fluid might reach the neck and predispose to upper airway constriction."

To determine whether that, in fact, was the case, the researchers recruited 23 nonobese subjects who were being evaluated for suspected OSA and performed standard sleep studies that assessed each subject for sleep stages and number of arousals, as well as oxygen saturation of the blood. The circumferences of their calves and necks were also measured at bedtime and upon awakening, before they got up.

Indeed, they found that the only significant correlate factor with respect to severity of OSA was the overnight change of fluid volume in the leg, which explained 67% of the variance in OSA severity. The change in fluid in the leg was, in turn, directly related to the amount of time the subject reported sitting each day.

"An important implication of our observations is that sedentary living may predispose to OSA not only by promoting obesity, but also by causing dependent fluid accumulation in the legs, which can shift rostrally to the neck overnight," said Dr. Bradley.

This finding may also help explain why 40 percent of patients with OSA are not obese, and why a reduction in OSA has been described when subjects begin exercise programs, even in the absence of weight loss.

New Method Could Pull the Mask Off Apnea Treatment

BALTIMORE, July 16 -- Delivering warm, humidified air through a nasal cannula can significantly reduce the symptoms of mild obstructive sleep apnea, researchers here say.
The treatment could eventually replace continuous positive airway pressure (CPAP) to control apnea, according to Hartmut Schneider, M.D., Ph.D., of Johns Hopkins Asthma and Allergy Center, and colleagues.
In the new method -- which uses a standard nasal cannula - "the nose is the mask," Dr. Schneider said.
"Treatment with nasal insufflation," as the method is called, could be more acceptable to patients than CPAP, which has an extremely low adherence rate, the researchers noted in the second July issue of the American Journal of Respiratory and Critical Care Medicine.
"We developed a simplified method for increasing pharyngeal pressure by delivering warm and humidified air at a continuous high flow rate through the open nasal cannula," they said.
To test the method, they performed a proof-of-concept study that included 11 patients with mild to severe apnea-hypopnea disorders. Apnea was defined as complete cessation of airflow for more than 10 seconds, while hypopnea was defined as a greater than 30% reduction of airflow.
The nasal cannula delivered humidified air - warmed to about 30 degrees C by a wire in the tube -- at a rate of up to 20 liters per minute, the researchers said.
In baseline testing the volunteers went to sleep with air flowing at five liters per minute. Once they reached a stable level of sleep, air flow was adjusted to zero, 10, or 20 L/min for five minute intervals in a random order.
Following the baseline tests, they were randomized to nights on and off at 20 L/min, the researchers said.
They found that the treatment:
Reduced the mean apnea-hypopnea index from 28 to 10 events per hour, which was significant at P<0.01.
Reduced the respiratory arousal index from 18 to eight events per hour (again significant at P<0.01).
Reduced the apnea-hypopnea index to fewer than 10 events per hour in eight of 11 volunteers, and to fewer than five events per hour in four participants.
"Although we expected marked improvements in the apnea-plus-hypopnea index primarily in patients with hypopneas rather than obstructive apneas, (the treatment) lowered the index in all subjects," the researchers reported.
While the finding is promising, they said, it still requires further clinical testing. Dr. Schneider said a larger clinical trial is currently under way in Germany and another is planned for the U.S.
He estimated that between a third and a half of apnea patients could benefit from the new method.
The "challenge in technology" was to find a way to provide air pressure in the nose and throat while improving comfort, Dr. Schneider said. Warming and humidifying the air proved to be the key.
"It's quite comfortable to wear the cannula," he said.
The study was partly supported by Seleon GmbH. Dr. Schneider receives consulting fees from Seleon and is entitled to royalty payments on the future sales of products described in the study. Co-author Alan R. Schwartz, M.D., of Johns Hopkins, also has financial links with Seleon. Primary source: American Journal of Respiratory and Critical Care MedicineSource reference: McGinley BM et al. "A Nasal Cannula Can Be Used to Treat Obstructive Sleep Apnea." Am J Respir Crit Care Med 2007; 176:194-200.

AAPA: Obstructive Sleep Apnea Wearies the Heart

PHILADELPHIA, May 29 -- The most obvious clinical feature of obstructive sleep apnea may be weariness of mind, but this breathing disorder also slowly and silently wears down the heart, according to researchers.
Recent evidence suggests that 60% of people hospitalized for myocardial infarction also have obstructive sleep apnea. Yet occurrence among the general population is only about 9%, said Jose R. Marquina, M.D., of the Collier County Medical Society in Naples, Fla., at the American Academy of Physician Assistants meeting here.
In addition, recent research also suggests that as many as 70% of patients hospitalized for stroke have obstructive sleep apnea as a comorbid condition, Dr. Marquina said.
During the night, severe sleep apnea sufferers stop breathing anywhere from 30 to 120 times per hour, and the resulting lack of oxygen in the body strains and stupefies the cardiovascular system, Dr. Marquina said.
Over the years, hypoxemia in patients with obstructive sleep apnea can damage the sinus node, the group of specialized heart cells that govern cardiac rhythm, he said. This hypoxic damage causes a variety of cardiac arrhythmias including bradycardia, atrial fibrillation, and sinus arrest.
In addition, he said, the stress of hypoxemia causes the body to release catecholines, a group of hormones linked to hypertension.
Oxygen levels in the blood are also involved in controlling pulmonary artery pressure, Dr. Marquina said, and chronic hypoxemia can, therefore, also lead to pulmonary hypertension. In fact, recent evidence suggests that 12% to 17% of patients with obstructive sleep apnea also have pulmonary hypertension, he said.
These cardiovascular effects of obstructive sleep apnea occur in addition to the more well known neurological effects, which include cerebral anoxia, cerebrovascular disease, and impaired memory and concentration, Dr. Marquina said.
Obstructive sleep apnea can also severely reduce a person's overall quality of life. The condition has been associated with poor performance at work or school, depression, and marital problems, he said.
Men are affected twice as often as women: occurrence is 4% among men versus 2% among women, Dr. Marquina said. The risk for obstructive sleep apnea also increases among those who are overweight. Among overweight men the occurrence rises to 24%, and it reaches 9% for overweight women, he said.
As many as 90% of cases of obstructive sleep apnea go undiagnosed, Dr. Marquina said. Clinicians should be more aware of the symptoms, which include excessive daytime sleepiness or tiredness upon waking. "The typical patient will say they slept for eight hours but woke up still feeling tired," he said.
Another symptom is loud snoring, although snoring also occurs normally in about 70% of individuals age 35 and older, Dr. Marquina said. Patients will often deny snoring, so it may be more useful to ask a bed partner about this condition, he added.
Up to five episodes of apnea per hour while sleeping is also normal for healthy individuals, Dr. Marquina said. But five to 15 episodes identified by polysomnography indicate mild obstructive sleep apnea, 15 to 30 are defined as a moderate condition, and 30 or more are defined as severe obstructive sleep apnea, he said.
In addition, obstructive sleep apnea tends to be associated with a neck circumference of 18 inches or more, he said.
"Obstructive sleep apnea must be treated not only to improve the symptoms of fatigue and overall quality of life but to prevent the development of cardiovascular problems," Dr. Marquina concluded.

AAPA: Obstructive Sleep Apnea May Lurk Behind A-Fib

PHILADELPHIA, May 29 -- More than half of patients with atrial fibrillation are also likely to have obstructive sleep apnea, investigators suggested here.
A small study of patients treated for atrial fibrillation at the investigator's practice found that 19% had been diagnosed with obstructive sleep apnea and 66% were at high risk for the condition, said Jonathan Gietzen, M.S., P.A.-C., of Heart Rhythm Consultants in Portland, Ore., and colleagues.
Previous studies have suggested that the hypoxic effects of obstructive sleep apnea might lead to atrial fibrillation, which is the most common sustained cardiac arrhythmia and affects an estimated two million Americans, Gietzen said at the American Academy of Physician Assistants meeting.
"If such a relationship exists, by screening patients with known atrial fibrillation for obstructive sleep apnea, you have detected a treatable condition that may help decrease the recurrence of atrial fibrillation," the investigators said.
"Similarly, by screening patients with known obstructive sleep apnea for atrial fibrillation, you can rule out other such complications of both disorders, such as heart failure and stroke," they said.
The study used the Berlin Questionnaire and the Epworth Sleepiness Scale to assess the risk for obstructive sleep apnea in patients treated for atrial fibrillation at a specialty cardiology office from 2004 through May 2006. The instruments were mailed to the patients, who filled them out and mailed them back.
A total of 66 patients were categorized as high-risk for obstructive sleep apnea according to their answers on the 10-question Berlin assessment. Of these, 19 reported a previous diagnosis of obstructive sleep apnea. None of the patients identified as low-risk reported a previous diagnosis of sleep apnea.
Patients in the high-risk group tended to have a higher body mass index than those in the low-risk group (mean BMI=31.3 versus 27.8; P=0.0076).
And significantly more patients in the high-risk group had a history of hypertension (49 patients versus 7 in the low-risk group; P<0.0001).
Gender did not appear to be a factor, the investigators said, with males comprising 75% of the high-risk group and 65% of the low-risk group (P=0.15).
In addition, the Epworth Sleepiness Scale revealed that 57% of patients reported being excessively sleepy, a possible indicator of obstructive sleep apnea, the authors said.
"As the number of patients with atrial fibrillation continues to grow nationwide, it is of utmost importance to find the predisposing factors. With obesity and hypertension being risk factors for both atrial fibrillation and obstructive sleep apnea, it is of clinical importance to look at the possible connection between the two disorders," the authors said.
"With the evidence that such a high prevalence of patients with atrial fibrillation also exhibit signs of obstructive sleep apnea, they concluded, the presence of obstructive sleep apnea should be considered in all patients with atrial fibrillation," especially those who are obese and have hypertension.
"However, the association between obstructive sleep apnea and atrial fibrillation is controversial because of the multiple confounding variables that occur frequently in both," the investigators acknowledged.

AAPA: Most Doctors Don't Ask About Sleep Problems

PHILADELPHIA, May 29 -- Millions of Americans suffer from undiagnosed obstructive sleep apnea, narcolepsy, and other sleep problems, in part because most physicians simply don't ask patients about them.
In fact, 70% of primary care physicians said they did not ask patients about the quality of their sleep, according to a National Sleep Foundation poll published in 2005, said Eric Kirsch, PA-C, of United Sleep Medicine, a provider of sleep and neurology services based in Charlotte, N.C.
The reason doctors don't ask about sleep may be that they have little training in sleep disorders, Mr. Kirsch said at an industry-sponsored symposium held in conjunction with the American Academy of Physician Assistants conference here.
A 1990 study of 126 accredited U.S. medical schools found that students received an average of only 1.6 hours of instruction about sleep disorders, he said. At 37 of these schools, students received less than one hour of sleep disorder education during their first two years, he said.
The result is that sleep disorders are significantly underdiagnosed, said Paul P. Doghramji, M.D., FAAFP, a private practitioner and associate of Pottstown Medical Specialists, Inc., of Pottstown, Pa.
About 30% of men and 21% of women suffer from excessive daytime sleepiness, according to recent research, Dr. Doghramji said. But only 10% to 20% of people with obstructive sleep apnea syndrome and only 15% to 20% of individuals with narcolepsy are ever diagnosed and treated, he said.
Lack of quality sleep can have serious consequences, he noted. For example, from 1% to 4% of U.S. highway automobile crashes are caused by sleepiness, and 4% of fatal crashes are caused by driver drowsiness, according to estimates from the National Highway Traffic Safety Administration, he said.
A person trying to function on only four hours of sleep is as impaired as a person with a blood alcohol level of 0.095, which is above the legal definition of intoxication in many states, said Dr. Doghramji, quoting a study of healthy volunteers that appeared recently in the journal Sleep.
Excessive sleepiness or fatigue have also been linked to endocrine disorders, immunologic disorders, neurological disorders such as Parkinson's disease and multiple sclerosis, and rheumatological disorders including fibromyalgia, Dr. Doghramji said.
Furthermore, nearly half (46.5%) of patients with excessive sleepiness also have a psychiatric disorder, such as anxiety, depression, or bipolar disorder, he said.
Psychiatric disorders such as these may sometimes be the cause of, not the result of, poor sleep quality and excessive sleepiness, Dr. Doghramji noted. Other causes include obstructive sleep apnea, narcolepsy, insomnia, circadian sleep rhythm disorders, and sleep-related movement disorders such as restless legs syndrome and periodic limb movement disorder, he said.
A variety of effective pharmacologic options for treating excessive sleepiness and some of its underlying causes are available to clinicians, said Jonathan R.L. Schwartz, M.D., of the University of Oklahoma Health Sciences Center in Oklahoma City.
Those include central nervous system stimulants such as dextroamphetamine and methylfenidate, which are FDA-indicated for treating narcolepsy, Dr. Schwartz said. These agents promote dopamine, serotonin, and norepinephrine neurotransmission, he said. Side effects may include anxiety, restlessness, insomnia, headache, tachycardia, hypertension, and psychosis, he noted. They are classed as schedule II controlled substances.
The wake-promoting agent modafinil is FDA-approved for treating excessive sleepiness associated with narcolepsy, obstructive sleep apnea, and shift work disorder, said Dr. Schwartz. Shift work disorder is a condition that affects about 32% of workers on the night shift and about 26% of rotating shift workers, he said.
Modafinil is thought to work by increasing activity in the hypothalamus. Side effects include headache, nausea, rhinitis, back pain, diarrhea, dyspepsia, anxiety, dizziness, and insomnia, he said. The drug is classed as a schedule IV2 controlled substance, he said.
If insomnia is the cause of excessive sleepiness, a variety of hypnotic medications can be used to promote sleep, including zolipidem, zaleplon, eszopiclone, and ramelteon, Dr. Schwartz said. If restless legs syndrome is the culprit, on the other hand, pharmacologic options include ropinirole and pramipexole. However, Dr. Schwartz did not discuss the mechanisms of action or potential side effects of the above-mentioned drugs. Iron replacement therapy may also be useful in patients with restless legs who have iron deficiency, he said.