CPAP lowers vascular inflammation, unstable plaque volume in OSA

Key takeaways:

• Changes in early atherosclerotic processes in patients with OSA were assessed via two imaging techniques.
• Patients receiving CPAP plus liraglutide also had lower unstable plaque volume at week 24.

Adults with obstructive sleep apnea treated with CPAP for 24 weeks had improved vascular inflammation and lower unstable plaque volume, according to results published in Annals of the American Thoracic Society.

In contrast, adults with OSA receiving 24-week liraglutide, a glucagon-like peptide (GLP)-1-mediated weight loss regimen, did not experience these outcomes, according to researchers.

“The statistical differences in improvement in vascular inflammation between the treatment arms are particularly striking,” Cliona O’Donnell, MBBS, specialist registrar in respiratory medicine at Connolly Hospital Blanchardstown in Dublin, and colleagues wrote.

In this randomized proof-of-concept study, O’Donnell and colleagues analyzed 30 adults (mean age, 50 years; 20% women; mean BMI, 35 kg/m²) newly diagnosed with OSA to determine the impact of 24-week CPAP (n = 10) vs. liraglutide (n = 10) vs. CPAP plus liraglutide (n = 10) on early atherosclerotic processes.

Using ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography-CT (18F-FDG-PET-CT) and coronary CT angiography, researchers evaluated changes in aortic wall inflammation and coronary plaque between the groups from baseline to week 24.

Notably, patients did not have a history of diabetes, heart failure or unstable CV disease.

Researchers did not find any significant differences in baseline characteristics between the three groups.

The number of patients in each group slightly shifted due to reports of intolerance or side effects following the start of the assigned treatment, resulting in 11 patients receiving CPAP, 10 patients receiving liraglutide and nine patients receiving CPAP plus liraglutide.

Between baseline and week 24, the apnea-hypopnea index (AHI) went down by an average of 45 events per hour in the CPAP group, 43 events per hour in the CPAP plus liraglutide group and 12 events per hour in the liraglutide group (P < .05).

In terms of weight loss, researchers noted significant decreases among patients receiving liraglutide (–6.17 kg) and patients receiving CPAP plus liraglutide (–3.67 kg).

The only group in which vascular inflammation, measured via aortic wall target-to-background ratio, was significantly reduced from baseline to week 24 was those receiving CPAP (2.03 to 1.84; P = .01). This change is “associated with an improvement in endothelial function and a decrease in C-reactive protein,” according to researchers.

Within the total cohort, six patients in the CPAP group, six patients in the liraglutide group and five patients in the CPAP plus liraglutide group had coronary artery plaque at baseline.

Those receiving CPAP experienced a decline in low-attenuation coronary artery plaque volume/unstable plaque volume over the course of 24 weeks (571 mm³ to 334 mm³). Additionally, the CPAP plus liraglutide group had lower unstable plaque volume at week 24 (401 mm³ to 278 mm³).

“Our data provide sufficient evidence to mandate the design and delivery of larger scale studies to define the role of CPAP in attenuating CV risk as primary prevention in subjects with OSA, and there is a clear need to integrate novel radiological surrogate markers of CV disease with clinical endpoints,” O’Donnell and colleagues wrote.