Study Suggests Long-Term CPAP Therapy Improves OSA Severity

A new investigation into obstructive sleep apnea (OSA) concluded that active screening and long-term continuous positive airway pressure (CPAP) intervention could improve the severity of severe OSA in patients following short-term CPAP withdrawal.

Currently, CPAP is the first-line therapeutic option for OSA. Despite this, investigators noted that many patients with OSA do not tolerate CPAP therapy.

Though recent research has focused on improving adherence, few have addressed the question as to whether patients must remain on CPAP therapy once prescribed.

As such, a team led by Qiong Ou, PhD, Southern Medical University in China, detailed the implications of long-term CPAP therapy on apnea-hypopnea index (AHI) following CPAP withdrawal.

Subjects for the study were enrolled from a group of civil servants who participated in an annual health examination from September-December 2017 in Guangzhou and Guangdong Province, China.

The team utilized the Berlin questionnaire to identify high-risk OSA patients in these populations, and those who were identified as high-risk experienced home sleep testing.

Nasal airflow, nocturnal oxygen saturation, heart rate, and respiratory effort were evaluated.

Obstructive apnea was defined as a decrease in respiratory airflow by ≥90% of pre-event baseline for ≥10 s with continued respiratory effort, and obstructive hypopnea was defined as a decrease in respiratory airflow by ≥30% of pre-event baseline for ≥10 s followed by a decrease in SaO2 of ≥3%.

Meanwhile, AHI was defined as the number of apneas and hypopneas per hour of sleep. Patients were diagnosed as OSA based on an AHI of ≥5 events/h.

Eligible patients were screened before undergoing a 1-week CPAP adherence assessment. From there, patients were followed up frequently for 2 years at months 1, 3, 6, 18, 12, 18, and 24 months.

By the end of the study, OSA patients underwent home sleep testing (HST) again within 1 week of CPAP withdrawal, and the effect of 2-year CPAP treatment on OSA severity was investigated.

A total of 103 patients with OSA were screened, 41 of whom were featured in the CPAP treatment group while 62 were included in the non-CPAP treatment group.

Following CPAP withdrawal, a significant decrease in AHI was observed in patients with severe OSA (P = 0.014) in CPAP treatment group at the 2-year follow-up period.

Regarding the non-CPAP treatment group, a significant increase in AHI was observed in patients with moderate OSA (P = 0.028).

Notably, a multivariate linear regression showed that AHI was negatively associated with CPAP treatment (P=0.030), while a multinominal logistic regression showed that the AHI of patients who weren’t treated with CPAP was either unchanged or worsened (P=0.032).

The investigators felt that the study indicated a delay in the progression of OSA severity due to long-term CPAP therapy.

“The present study provides a new model for the management of OSA, namely, active OSA screening and intervention in general population,” the team wrote. “Our results have obvious clinical implications in enhancing the beliefs of treating disease and improving adherence to CPAP therapy for OSA patients, especially in the mode of active screening for OSA and intervention.”

The study, "The effects of long-term continuous positive airway pressure on apnea–hypopnea index change following short-term that withdrawal in patients with obstructive sleep apnea," was published online in The Clinical Respiratory Journal.