Role of Biomarkers to Screen for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a disorder with high prevalence, estimated to occur in 34% of men and 17% of women , afflicting more than 100 million adults worldwide.

OSA is the third most common serious respiratory condition after Asthma and COPD.

Patients with untreated OSA are at increased risk for hypertension, cardiovascular disease, heart failure, stroke, obesity, metabolic dysregulation, diabetes mellitus, daytime sleepiness, depression, accidents and are a significant burden on the healthcare system.

Unfortunately, up to 90% of individuals with OSA remain without a diagnosis or therapy.

The association between OSA and adverse health consequences has led the American Heart Association and others to suggest that OSA screening be integrated into routine clinical care.

Current tools for OSA screening rely on questionnaires with low diagnostic accuracy from low-quality studies, as reported in meta-analyses, OSA screening measures that are frequently used include the Epworth Sleepiness Scale (ESS) and STOP-Bang questionnaires.

The ESS assesses subjective daytime sleepiness but is nonspecific for OSA, was not designed nor validated for OSA screening.

The recent American Academy of Sleep Medicine (AASM) clinical practice guidelines report that more accurate and user-friendly screening tools, such as blood bio-markers, are needed to better predict OSA diagnosis and severity, a recent review of potential OSA bio-markers concludes that an optimal screening test should be clinically sensitive, specific, simple, timely, inexpensive, and correlate to disease severity.

Furthermore, bio-markers should make pathophysiological sense, reflecting functional changes that accompany OSA.

Numerous individual OSA blood bio-markers have been studied previously dysfunctions in metabolic and endocrine systems induced by OSA, chronic inflammation, hypoxemia, sleep fragmentation, and stress are associated with alterations in bio-markers. These bio-markers include glycated hemoglobin (HbA1c), C-reactive protein (CRP), erythropoietin (EPO), and uric acid,Unfortunately, the diagnostic utility of individual bio-markers or combinations of markers is inconclusive in identifying OSA.