Results of CPAP Titration and Short-Term Adherence Rates in Patients with Obesity Hypoventilation Syndrome and Mild/Moderate Obstructive Sleep Apnea

Abstract

Purpose No study has assessed the titration success of CPAP therapy in patients with obesity hypoventilation syndrome (OHS) and an apnea-hypopnea index (AHI) <30 event/h. This study aimed to assess the titration success of CPAP therapy under polysomnography and subsequent short-term adherence (1 month) in patients with OHS and an AHI <30 event/h. Methods Consecutive OHS patients with an AHI <30 events/h between 2010 and 2019 were included (n=54). All OHS patients were first started on CPAP during the therapeutic sleep-study. If the therapeutic-study showed that the SpO2 remained < 90% for 20% of the total sleep time, a second therapeutic study was arranged with bi-level PAP (BPAP). Thirty patients agreed to participate in the 1-month follow-up adherence study. We applied the American-Thoracic-Society criteria for PAP adherence. Results The mean age was 54.8±14.6 years, and the mean BMI was 45.9±12.2 kg/m 2 . Successful titration on CPAP was attained in 36 (66.7%) patients, and 18 (33.3%) required BPAP. Patients who failed the CPAP trial had a significantly higher PaCO2 and bicarbonate, a more restrictive respiratory pattern on spirometry, and a significantly higher time with SpO2<90% (mins) during sleep. The only independent correlate of CPAP-titration success on the multivariable regression analysis was the desaturation index (OR: 1.33 [1.033–1.712]). More than 80% of the participants were using CPAP therapy after one-month with no differences in adherence between the CPAP and BPAP groups. Conclusions The current results suggest that CPAP therapy could be an acceptable alternative therapy to BPAP in patients with OHS without severe OSA.