Furthermore, while non-randomized observational trials have suggested that the risk of adverse cardiovascular events is lower among patients who accept treatment by CPAP than in patients who do not accept CPAP therapy, it is possible that this difference may be due to better overall adherence to all prescribed treatments in patients who accept CPAP than in those who do not, as opposed to any direct benefit of CPAP itself.
Whereas physiological studies suggest that OSA provides a substrate for the development of atherosclerosis, and epidemiological and observational studies suggest an association between OSA and odds of having atherosclerosis, there remains a gap between cause and effect yet to be filled, wrote Drs. Yumino and Bradley. Drager and colleagues provide evidence that begins to fill that gap.
Indeed, after four months of CPAP therapy, carotid intima-media thickness declined by nine percent, which is remarkable in light of the fact that in a large-scale study, patients undergoing cholesterol-lowering pravastatin therapy saw carotid intima-media thickness decline by twelve percent after a full year. Other indicators showed similar magnitudes of improvement.
The researchers put forth a number of potential pathways whereby OSA could contribute to atherosclerosis progression, including inflammation, oxidative stress, lymphocyte activation, and high-density lipoprotein dysfunction. CPAP treatment could reverse several of these pathways, they wrote.
Still, the investigators caution that, while they are confident in the biological validity of their results, the rigid inclusion criteria makes it dif
|Contact: Keely Savoie|
American Thoracic Society