The overlap syndrome (OS), which refers to the co-occurrence of OSA and COPD, was first described by Flenley in 1985 (Flenley DC. Clin Chest Med. 1985;6[4]:651). Over the years, numerous studies have demonstrated an increased risk of hospitalization and mortality in patients with OS (Brennan M, et al. 2022;1-10). Despite these findings, limited evidence exists regarding the optimal treatment approach for individuals with OS.
CPAP therapy has demonstrated various physiologic advantages for patients with OS (Srivali N, et al. Sleep Med. 2023;108:55-60), which contribute to diminished dyspnea symptoms, lowered pro-inflammatory markers, improved arterial blood gases, increased 6-minute walk distance, enhanced FEV1, and decreased mean pulmonary artery pressure (Suri TM, et al. FASEB BioAdv. 2021;3[9]:683-93). CPAP therapy in patients with OS has been linked to a reduction in COPD exacerbations (Voulgaris A, et al. Clin Respir Jour. 2023; 17[3]:165), fewer COPD-related hospitalizations (Marin JM, et al. Am J Respir Crit Care Med. 2010;182[3]:325-31), decreased cardiovascular events (Kendzerska T, et al. Ann ATS. 2019;16[1]:71), and an overall decline in mortality rates (Machado ML, et al. Eur Respir J. 2010;35[1]:132-7).
It is important to acknowledge that, as of now, no randomized clinical trial has specifically addressed the treatment of OS, leaving recommendations largely reliant on observational studies. Conversely, recent guidelines have proposed the utilization of high-intensity noninvasive ventilation (NIV) for hypercapnic patients with COPD. Thus, extensive research is warranted to characterize distinct sleep-related breathing disorders within the OS population and to investigate the effects of CPAP in comparison to other NIV modalities on patients with overlap syndrome.