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Beckman Coulter, Brea, Calif, has announced positive results of a clinical trial suggesting that blood tests may offer key benefits in the initial screening for obstructive sleep apnea. The study, which included 264 male adult patients from six institutions, revealed that screening for changes in three specific biomarkers may help identify the often-serious disorder that affects an estimated 100 million adults worldwide. Researchers anticipate that these objective blood tests will improve screening accuracy and timely diagnosis as well as patient management.1
Beckman Coulter is currently the only supplier to offer this panel of three assays on fully automated platforms. Hemoglobin A1c (HbA1c) and C-reactive protein (CRP) are chemistry tests on the company’s Synchron and AU systems, while erythropoietin (EPO) testing is performed on the company’s DxI and Access 2 immunoassay systems.
Approximately 34% of men and 17% of women experience sleep apnea, a common disorder characterized by brief patterns of interrupted breathing during sleep.2 Obstructive sleep apnea occurs when the throat muscles relax, constricting the airway. The prevalence of sleep apnea is on the rise due to an aging population and increasing obesity rates. However, 90% of individuals with sleep apnea remain undiagnosed and untreated.
“The study results demonstrate that sleep apnea induces a characteristic signature cluster of blood biomarker changes,” says principal investigator and lead author Wesley Elon Fleming, MD, diplomate of the American Boards of Sleep Medicine and Neurology, of the Sleep Center Orange County. “Concurrent elevations of HbA1c, CRP, and EPO levels should generate a high index of suspicion of obstructive sleep apnea, and thus, may be useful as an initial screening tool in adult males.”
“The combination of these three blood tests correlates with the severity of disease and may assist sleep centers in identifying and triaging patients for diagnosis and treatment,” notes Jon-Erik Holty, MD, of Stanford Medical School and the VA Palo Alto Health Care System. “Undiagnosed and untreated sleep apnea patients place a significant clinical and economic burden on the healthcare system.”
Tools that help identify patients in need of treatment in a timely manner may help to reduce that burden. However, diagnosing this condition has remained a challenge, and many people with sleep disordered breathing are unaware of its associated symptoms. As a result, physicians need effective and easy-to-use screening solutions.
“Important to note is that the blood tests were superior to standard screening methods, such as the Epworth Sleepiness Scale and STOP-Bang questionnaires, in identifying obstructive sleep apnea,” says Rohit Budhiraja, MD, of Harvard Medical School and Brigham and Women’s Hospital.
Additionally, the blood tests demonstrated superiority over the use of BMI as an indicator in non-obese patients—a significant finding, given that up to half of patients with sleep apnea are not obese.
“The combination of the three identified biomarkers performed as well for asymptomatic patients as it did for symptomatic patients,” notes Edith Mensah-Osman, MD, PhD, MBA, president, CEO, and director of medical research at EENA Comprehensive Neurology and Sleep Center.
Patients with sleep breathing disorders are at increased risk for cardiovascular disease, diabetes, and other chronic conditions. This relationship between sleep apnea and adverse health consequences led the American Heart Association to suggest the integration of screening for sleep apnea into routine clinical care.
“Patients at risk of sleep apnea are currently unlikely to be referred to a sleep center,” says Richard Bogan, MD, FCCP, FAASM. “Only 30% of patients are cautioned about sleep apnea by their primary care provider, who is frequently the first contact for patients seeking a diagnosis.”
“Sleep apnea patients were found to have an increased probability of prediabetes and intermediate to high cardiovascular risk,” adds Michael Samoszuk, MD, study coauthor and chief medical officer at Beckman Coulter. “Sleep apnea-induced hypoxemia is associated with increased EPO concentrations. Hence, there is biological plausibility for including these three blood tests in the biomarker panel for sleep apnea.”
“After diagnosis and treatment, improvements are observed in sleep quality, quality of life, and blood pressure,” says Dennis Hwang, MD, of Kaiser Permanente Sleep Center, “which may reduce the risk of heart disease and chronic health conditions and decrease healthcare utilization and cost.”
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