Defining obstructive sleep apnoea syndrome: a failure of semantic rules

Abstract

Obstructive sleep apnoea syndrome (OSAS) is one of the most ubiquitous medical conditions in industrialised society. Since the recognition that symptoms of excessive daytime somnolence, problems with concentration, mood and cognitive impairment, as well as cardiometabolic abnormalities can arise as a consequence of obstructed breathing during sleep, it has been subject to variation in its definition. Over the past five decades, attempts have been made to standardise the definitions and scoring criteria used for apnoeas and hypopnoea, which are the hallmarks of obstructive sleep apnoea (OSA). However, applying these definitions in clinical and research practice has resulted in over- and under-estimation of the severity and prevalence of OSAS. Furthermore, the definitions may eventually become redundant in the context of rapid technological advances in breathing measurement and other signal acquisition. Increased efforts towards precision medicine have led to a focus on the pathophysiology of obstructed breathing during sleep. However, the same degree of effort has not been focused on how and why the latter does or does not result in diurnal symptoms, integral to the definition of OSAS. This review focuses on OSAS in adults and discusses some of the difficulties with current definitions and the possible reasons behind them.

Update on the genetic basis of obstructive sleep apnoea – hype or hope?

“…,41]. The International Classification of Sleep Disorders definitions of OSA have also changed markedly over time and consider OSAS a synonym, rather than a separate entity thereby introducing significant imprecision into the definition of what is being studied [41]. The current International Classification of Sleep Disorders, third edition, text revision (ICSD-3-TR) released in 2023 [42], for instance, has changed the goalposts again by removing any reference to cardiometabolic comorbidities included in the ICSD-3 [43] and using an AHI of 15 regardless of the presence of symptoms as diagnostic of the disorder when clearly, the two entities can be very different.…”

“…With respect to sleep disordered breathing, the ‘objective’ metric is the apnoea–hypopnoea index (AHI) on polysomnography (and A+H per estimated hour of sleep if derived using Type III devices), which are also subject to different definitions and have changed over the decades [8,9 ▪ ,10,11 ▪▪ ,41].…”

“…OSA, in some respects, is somewhat easier to define, but OSAS, whereby the symptoms and negative consequences of OSA are incorporated into the definition, is much more difficult to categorize. The syndrome is comprised of two major components which are both derived, measured, and rated differently: the number of apnoeas/hypopnoeas per hour of sleep and daytime consequences such as sleepiness, impaired mood, memory and concentration [41].…”

Upper Airway Expansion in Disabled Children

“…It is characterized by episodes of partial or complete obstruction of the upper airway during sleep, interrupting (apnea) or reducing (hypopnea) the flow of air, followed by brief awakening that leads to the restoration of upper airway permeability. The descriptions may eventually become redundant in the context of rapid technological advances in breathing measurement and other signal acquisition [28].…”

Towards automatic home-based sleep apnea estimation using deep learning

“…During OSA events, nasal airflow ceases for a short time, but the brain and body fight to keep breathing. OSA has been associated with an increased risk of heart disease, diabetes, chronic kidney disease, stroke, depression, and cognitive impairment [2]. As age and the likelihood of having sleep apnea are positively correlated [4], the growing number of patients with OSA is expected to increase pressure on healthcare systems.Typically, the diagnosis and detection of OSA are based on polysomnography (PSG) tests conducted in a sleep facility [5].…”