New, Low-Cost Screening Process for Obstructive Sleep Apnea

Measuring the oxygen desaturation index (ODI) with overnight pulse oximetry is an effective, low-cost way to screen for obstructive sleep apnea (OSA), a new study published in the Journal of Clinical Sleep Medicine suggests.
OSA is often underrecognized in hospitalized patients and associated with significant morbidity and mortality, according to researchers from Thomas Jefferson University and Hospitals, in Philadelphia.
“Sleep disordered breathing is associated with cardiovascular complications and sudden death,” said lead study author Sunil Sharma, MD, FAASM, associate professor of pulmonary medicine in the Sidney Kimmel Medical College at Thomas Jefferson University, in a press release.
The researchers conducted a prospective study with 754 patients to test the efficacy of this screening for identifying OSA in patients admitted to a tertiary care hospital. The patients were admitted between February 2013 and February 2014.
Obese patients (body mass index >30 kg/m2) were automatically screened for OSA—being overweight is a risk factor for OSA—using the STOP (snoring, tiredness during daytime, observed apnea, high blood pressure) questionnaire. Patients with positive results were advised to have a follow-up evaluation, which included an overnight polysomnography.
The optimal screening cutoff for OSA was ODI greater than or equal to 10 events per hour (Matthews correlation coefficient, 0.36; 95% CI, 0.24-0.47). The researchers found that 129 of the 149 patients who underwent polysomnography were shown to have OSA.
“The results showed that our screening process identified sleep disordered breathing in 87% of patients who followed up with a polysomnography,” said Dr. Sharma. “We confirmed the high prevalence of undetected sleep-disordered breathing among hospitalized patients and also validated a low-cost protocol to detect it.”
The authors noted a significant increase in the number of hospitalized patients recommended to undergo polysomnography after implementing this screening process.
“This study should be of great interest to hospitals looking at ways to reduce complications,” said Dr. Sharma. “Recent data suggests that for inpatients with cardiovascular disorders, early diagnosis and intervention for sleep apnea may lead to reduced readmission rates.”

The Effect of OSA on Work Disability and Work-Related Injuries

OSA is a common yet underdiagnosed respiratory disorder characterized by recurrent upper airway obstruction during sleep. OSA results in sleep fragmentation and repetitive hypoxemia and is associated with a variety of adverse consequences including excessive daytime sleepiness, reduced quality of life, cardiovascular disease, decreased learning skills, and neurocognitive impairment. Neurocognitive impairments that have been linked to poor sleep include memory deficits, decreased learning skills, inability to concentrate, and decreased alertness. Furthermore, the societal and economic costs of OSA are substantial; for example, patients with OSA have a significantly greater risk of motor vehicle crashes, consume more health-care resources, and have associated annual costs in the billions of dollars per year. It is increasingly recognized that OSA may also have substantial economic consequences. Specifically, there is accumulating evidence implicating OSA as an important contributor to work disability (including absenteeism, presenteeism) and work-related injuries. This review summarizes the current state of knowledge in these two areas.

Sleep Apnea Linked to Depression in Men

Obstructive sleep apnea (OSA) is associated with an increased risk of depression in men, a large Australian study found.

Among 1,875 men ages 35 to 83 who were assessed for depression at two time points about 5 years apart in the Men Androgen Inflammation Lifestyle Environment & Stress Study (MAILES), previously undiagnosed severe OSA was associated with depression (OR 2.1, 95% CI 1.1-4, P<0.05), reported Carol J. Lang, PhD, of the University of Adelaide, at theannual meeting of the American Thoracic Society here.

This statistical significance remained even after adjustment for age, waist circumference, smoking, relationship status, financial difficulties, erectile dysfunction, and nocturia, she noted.

“Depression is highly prevalent in OSA, reaching 39% in clinic studies. However, few population-based studies have been done and results have been mixed,” Lang said.

In one longitudinal study that included 1,400 men and women, a dose-dependent association between a sleep-related breathing disorder and depression was seen, with a 2.6-fold increased risk of depression and a moderate or severe sleep-related breathing disorder.

A cardinal symptom of OSA is excessive daytime sleepiness, although not all affected patients report this problem. It’s unclear whether daytime sleepiness is associated with depression in OSA, and in the longitudinal study, sleepiness was not found to be an explanatory factor for the observed relationship between the sleep-related breathing disorder and depression.

Further complicating this relationship was the finding in another study that residual sleepiness persisting after continuous positive airway pressure treatment was linked with refractory depression.

In an attempt to clarify the association of OSA and depression, in 2010 Lang and colleagues conducted telephone interviews asking men if they had ever been diagnosed with sleep apnea with a sleep study, and those answering in the negative were invited to participate. A total of 857 men then underwent at-home polysomnography testing.

Depression was assessed using the Center for Epidemiologic Studies Depression Scale/Beck’s Depression Inventory, and daytime sleepiness was evaluated according to the Epworth Sleepiness Scale.

OSA was defined as an apnea-hypopnea index higher than 10. Mild-to-moderate OSA was an index score of 10 to 29, and severe was 30 or higher.

Logistic regression analysis determined that, along with severe OSA, daytime sleepiness was associated with depression (OR 1.1, 95% CI 1-1.2, P<0.05).

Then, in a model that included both previously undiagnosed OSA and excessive daytime sleepiness, individuals with both had 4.2 times greater odds of depression than those with neither, and 3.5 times greater likelihood of depression than those with either alone.

“The message is that clinicians need to be aware of these risks and assess for the other if one is present,” Lang said.

The precise mechanisms underlying the link between these conditions are uncertain, but may involve low oxygen levels, arterial inflammatory responses, and neurologic changes in the brain, she said.

The press conference moderator, Mihaela Teodorescu, MD, of the department of pulmonary and critical care at the University of Wisconsin in Madison, agreed that this is an important clinical issue.

“Sleep apnea leads to more refractory depression and patients get more treatment, including with benzodiazepines, which can aggravate and further contribute to depression,” she said.

Suspect OSA in patients with unexplained daytime sleepiness

Adult patients who are excessively sleepy during the day for no apparent reason should be targeted for assessment of obstructive sleep apnea (OSA) using a sleep study, a new guideline from the American College of Physicians (ACP) recommends.

Sleep study records patients’ brain activity, eye movements, heart rate, and blood pressure during sleep to diagnose OSA and determine disease severity.

In patients whom OSA is suspected, the guideline recommends full-night, in-laboratory polysomnography (PSG) to establish the diagnosis. This test requires specialized facilities, is expensive and demands that patients spend the night under observation in a foreign environment, but yields the most accurate diagnostic information. [Ann Intern Med 2014;161:210-220]

Home-based portable sleep monitors may be used as an alternative in patients without comorbid conditions or when PSG is not available, although these can yield substantially different scores on the apnea-hypopnea index (AHI), which accounts for the number of pauses in breathing per hour of sleep.

Daytime sleepiness (hypersomnia) is a clinically relevant symptom of OSA, but clinicians should also include in their assessment other symptoms such as fatigue, insomnia and snoring, and risk factors such as obesity, said the guideline authors.

Clinicians are not advised to assess OSA in the absence of daytime sleepiness or treat patients with low AHI scores as evidence suggests neither improves clinical outcomes. Of note, portable monitoring in patients with chronic lung disease, congestive heart failure, neurologic disorders and other major comorbidities is also not recommended as very few studies included these patients. There is also little evidence for pre-operative screening for OSA and its effect on surgical outcomes.

The guideline, which is based on reviews of peer-reviewed studies published from 1996 to May 2013, is developed to provide clinicians with guidance on diagnosing OSA. For guidance on treatment, clinicians could refer to the ACP guideline on the management of OSA.

“Obstructive sleep apnea is a serious health condition that is associated with cardiovascular disease, hypertension, cognitive impairment, and type 2 diabetes,” said ACP president Dr. David Fleming. “It is important to diagnose individuals with unexplained daytime sleepiness so that they can get the proper treatment.”

FDA Approves Inspire Device for OSA.

The FDA has approved an upper airway stimulation device to treat a subset of obstructive sleep apnea (OSA) when standard therapy isn’t an option, device maker Inspire Medical Systems announced Thursday.

The neurostimulation device gained an indication for treating moderate-to-severe OSA (Apnea Hypopnea Index of 20 to 65 events per hour) in adults confirmed to have failed or not tolerated conventional continuous positive airway pressure (CPAP) treatment, largely following the recommendation of an FDA advisory panel in February.

Also, the patient anatomy has to be such that it wouldn’t make stimulation ineffective, particularly complete concentric collapse at the level of the soft palate.

That panel suggested contraindications in a large portion of sleep apnea patients — the obese, those with central and mixed apneas, and those with other implantable devices — but those were not included in the final approval.

The pacemaker-like implant in the chest sends a mild electrical jolt down a lead to the hypoglossal nerve at the base of the tongue, moving the tongue to clear the airway. A lead in the chest senses when to send the pulse in the breathing cycle.

This was the first such device to be approved for OSA, although others are in development.

An uncontrolled open-label trial had shown a drop in apnea-hypopnea index by 68% with the device, from a median 29.3 events per hour before implantation to nine after 1 year of use (P<0.001), and a similar 70% reduction in oxygen desaturation index score.

Morbidity and mortality in children with obstructive sleep apnoea: a controlled national study.


Background Little is known about the diagnostic patterns of obstructive sleep apnoea (OSA) in children. A study was undertaken to evaluate morbidity and mortality in childhood OSA.

Methods 2998 patients aged 0–19 years with a diagnosis of OSA were identified from the Danish National Patient Registry. For each patient we randomly selected four citizens matched for age, sex and socioeconomic status, thus providing 11 974 controls.

Results Patients with OSA had greater morbidity at least 3 years before their diagnosis. The most common contacts with the health system arose from infections (OR 1.19, 95% CI 1.01 to 1.40); endocrine, nutritional and metabolic diseases (OR 1.30, 95% CI 0.94 to 1.80); nervous conditions (OR 2.12, 95% CI 1.65 to 2.73); eye conditions (OR 1.43, 95% CI 1.07 to 1.90); ear, nose and throat (ENT) diseases (OR 1.61, 95% CI 1.33 to 1.94); respiratory system diseases (OR 1.78, 95% CI 1.60 to 1.98); gastrointestinal diseases (OR 1.34, 95% CI 1.09 to 1.66); skin conditions (OR 1.32, 95% CI 1.02 to 1.71); congenital malformations (OR 1.56, 95% CI 1.31 to 1.85); abnormal clinical or laboratory findings (OR 1.21, 95% CI 1.06 to 1.39); and other factors influencing health status (OR 1.29, 95% CI 1.16 to 1.43). After diagnosis, OSA was associated with incidences of endocrine, nutritional and metabolic diseases (OR 1.78, 95% CI 1.29 to 2.45), nervous conditions (OR 3.16, 95% CI 2.58 to 3.89), ENT diseases (OR 1.45, 95% CI 1.14 to 1.84), respiratory system diseases (OR 1.94, 95% CI 1.70 to 2.22), skin conditions (OR 1.42, 95% CI 1.06 to 1.89), musculoskeletal diseases (OR 1.29, 95% CI 1.01 to 1.64), congenital malformations (OR 1.83, 95% CI 1.51 to 2.22), abnormal clinical or laboratory findings (OR 1.16, 95% CI 1.06 to 1.27) and other factors influencing health status (OR 1.35, 95% CI 1.20 to 1.51). The 5-year death rate was 70 per 10 000 for patients and 11 per 10 000 for controls. The HR for cases compared with controls was 6.58 (95% CI 3.39 to 12.79; p<0.001).

Conclusions Children with OSA have significant morbidities several years before and after their diagnosis.

Source: Thorax