Prevalence of Central Sleep Apnea among Veterans and Response Rate to Continuous Positive Airway Pressure Therapy

Sleep-disordered breathing (SDB) is common in the Veteran population. In this retrospective study, we investigated the prevalence of comorbid central and obstructive SDB and the response rate to PAP among Veterans. Veterans were screened from a single VA medical center who had a polysomnography (PSG) study from 2017-2021 to ascertain the presence, severity, and type of SDB by measuring the Apnea-Hypopnea Index (AHI) and Central Apnea Index (CAI). Patients were excluded if they did not have complete studies (diagnostic and PAP titration studies). The inclusion criteria for these analyses were central sleep apnea (CSA) defined as AHI ≥ 10 events/hour and CAI ≥ 5 events/ hour. Diagnostic “CSA only” was defined as AHI ≥ 10 events/ hour and CAI ≥ 50% of AHI. “OSA only” was defined if AHI≥ 10 events/ hour and CAI < 5 events/ hour. Comorbid central and obstructive sleep apnea (COSA) was defined if AHI≥ 10 events/ hour and CAI > 5 events/ hour but <50% of AHI. The responsiveness to PAP therapy was determined based on the CAI < 5 events/h on the titration study. A total of 90 patients met the inclusion criteria and from those 64 Veterans were found to have COSA (71%), 18 (20%) were CSA only, and 8 (9%) were OSA only. A total of 22 (24.4%) Veterans diagnosed with CSA or COSA were responsive to PAP therapy. Sixty days after treatment initiation, both responsive and nonresponsive groups had significant decreases in AHI and CAI (p<0.05). Comorbid central and obstructive SDB is common among Veterans. The response to PAP therapy is suboptimal but improves over time.