Airflow

What to Look For:

The most common symptoms of sleep apnea include snoring, gasping, or choking during sleep, morning headaches, and daytime sleepiness. Risk factors associated with sleep apnea include high body mass index (BMI), obesity, older age (>40 years old), and certain anatomical features such as enlarged tonsils or upper airway abnormalities. Use of tobacco, alcohol, and certain sedative and pain medications may increase apnea severity.

Sleep apnea is a common comorbidity in patients with heart disease, stroke, high blood pressure, GI reflux disease, high cholesterol, and type II diabetes.

When measuring sleep respiratory events, the ‘gold standard’ is direct airflow measurement. Without it, a sleep test relies on indirect markers, such as peripheral arterial tonometry (PAT) signals and blood oxygen saturation. These indirect markers will not detect apnea events too short to cause significant desaturation, nor will they accurately differentiate between apnea and hypopnea.

Comorbid conditions complicate and limit indirect diagnostic methods

Sleep apnea patients are reported to have high rates of comorbid conditions, which can complicate or limit the effectiveness of indirect diagnostic methods.

A peer-reviewed study published in the Journal of Clinical Sleep Medicine evaluated PAT systems in a large point-of-care cohort, including patients with atrial fibrillation, congestive heart failure, asthma, COPD, and patients receiving pharmacologic therapies. The findings suggest that conditions and therapies which affect normal blood circulation, sympathetic tone, or oxygen saturation often compromise the accuracy of PAT-derived results. In particular, the study concluded, “the PAT-based testing presented high rates of diagnostic misclassification of sleep disordered breathing presence or severity.”

A second study published on June 1, 2022 in the Journal of Clinical Sleep Medicine confirmed significant discordance between PAT-based testing and in-lab polysomnography (PSG) among active-duty military personnel. The authors concluded, “PAT-based HSAT may have limited utility for diagnosing OSA and grading severity in this unique patient population.”

Snap Diagnostics’ approach

Snap Diagnostics’ home sleep test is unique in that it integrates the direct, ‘gold standard’ technology and analysis used in traditional laboratory-based sleep tests. It also makes testing more accessible and affordable. As a result, there are no medical conditions or therapies that preclude Snap testing.

To learn more about the published studies supporting this post, please reach out to your local Snap Manager or contact us.