A functional imaging study to evaluate aortic inflammation in OSA subjects

Abstract

Background: Obstructive Sleep Apnoea (OSA) is associated with increased cardiovascular risk in general and aortic dilatation in particular. However, it is unclear what pathophysiological mechanisms may account for this. We tested the hypothesis that aortic inflammation is increased in OSA subjects compared to healthy controls. A further aim was to compare aortic inflammation in OSA subjects to COPD patients, who also have increased cardiovascular risk. Methods: 6 treatment naive OSA subjects, 24 COPD subjects, and 12 never smokers (controls) from the EVOLVE (UKCRN ID 15153) study, underwent FDG PET/CT imaging to measure aortic inflammation. Aortic inflammation was quantified by the tissue-to-blood ratio (TBR). Aortic stiffness was determined by carotid-femoral aortic pulse wave velocity (aPWV). Results: Demographics are in Table 1. OSA and COPD subjects had both increased aortic inflammation (TBR: 2.20±0.02 and 1.92±0.01 respectively) compared to controls (1.77±0.01) p Conclusion: OSA is associated with increased aortic inflammation and stiffness; higher levels of aortic inflammation were seen in OSA than COPD subjects. We suggest that the intrapleural pressure changes associated with untreated OSA may cause aortic inflammation.