Obstructive sleep apnea (OSA) is a condition when episodes of a complete or partial collapse of the airways lead to decreased oxygen saturation or arousal from sleep. OSA is defined as ≥ 5 events/ hour and affects almost 1 billion people globally.44 A gold standard of OSA treatment is continuous positive airway pressure (CPAP) machine. Obstructive sleep apnea is strongly associated with hypertension, myocardial infarction, and stroke.
Unprovoked venous thromboembolic events (VTE) are another potential consequence of severe OSA. W. Trzepizur (France) reported a study showing that patients with OSA who had the longest nocturnal hypoxemia episodes had a twofold risk for venous thromboembolic events.45 The association between nocturnal hypoxemia and VTE was strongest among patients who did not use CPAP systems, which predisposed them to nighttime blood oxygen levels below 90% of normal. Hypoxia is known to be associated with VTE, and it confirms the finding that such patients had an almost twofold risk of developing VTEs as compared to patients without oxygen deprivation.45
A. Palm (Sweden) presented the results of a large population-based study that involved more than 60,000 patients with OSA who received CPAP therapy between 2010 and 2018.46 Those OSA patients who also had cancer showed higher sleep apnea severity, measured as elevated apnea-hypopnea index (AHI) or oxygen desaturation index (ODI). The researchers concluded that OSA-mediated intermittent hypoxia was independently associated with cancer.
During the period from 1999 to 2017, there were 813 OSA clinical trials, with the majority examining various therapeutic options such as CPAP interventions (43.7%) and pharmacotherapies (19.2%).47 A search of clinicaltrials.gov showed similar results, with 182 interventional clinical trials recruiting as of 07 October 2022, with 23 (12.6%) of them investigating drugs for OSA treatment and 78 (42.9%) testing different devices.48 However, most of the devices tested were variations of CPAP with a different oxygen flow or cannula.
While a breakthrough in OSA treatment in the near future is unlikely, it could be considered a frequent comorbidity in clinical trials among various indications due to the high prevalence of this condition in the general population. Considering changes in pathology and complications caused by OSA when monitoring the safety of investigational products is crucial for ensuring the most effective treatments.
The main challenge stems from the ability of patients to tolerate the machine and the continuous flow, and patient adherence to the treatment is thought to be 50-80%.
