Researchers in Brazil have found that treating patients who suffer from obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) dramatically reduces early indications of atherosclerosis in just months, linking OSA directly to the hardening or narrowing of the arteries. Until now, no study has demonstrated such a direct relationship between the two.
OSA is independently associated with increased risk of fatal cardiovascular events that can be reversed by treatment with CPAP, wrote Luciano Drager, M.D., of the University of So Paulo Medical School in Brazil.
The research was published in the first issue of the American Journal of Respiratory and Critical Care Medicine for October of 2007, published by the American Thoracic Society.
The researchers selected 24 men with severe OSA and no other comorbidities and randomly assigned them to receive either CPAP therapy or no treatment. After establishing the baseline data for each subject, they then tracked several indicators of pre-clinical atherosclerosis, including carotid intima-media thickness (a measure of arterial plaque), pulse-wave velocity (a measure of arterial stiffness), carotid diameter, C-reactive protein (a marker of inflammation), and catecholamine level (a marker of physical stress) over the course of four months.
[All markers] were similar across the study period in the control group, wrote Dr. Drager. In contrast, the group treated with CPAP had a significant decrease in carotid intima-media thickness, pulse-wave velocity, C-reactive protein, and catecholamines.
While there is a known association between OSA and risk of myocardial infarctions and strokes, the causal connection between OSA and atherosclerosis as the principle mechanism behind those cardiovascular events has proven difficult to establish.
The majority of patients with OSA share several risk factors for atherosclerosis, including obesity, hypertension, hyper
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American Thoracic Society