Obstructive Sleep Apnea — A Risk Factor for Coronary Artery Disease

An on-going study taking place in Sweden has released preliminary findings that suggest that obstructive sleep apnea (OSA) may be an even stronger risk factor for coronary artery disease than diabetes, obesity, hypertension and even smoking.

At the European Respiratory Society 2010 Annual Congress last week, Swedish pulmonoligist Yuksel Peker from the Skaraborg Hospital in Sweden presented his latest finding from the ongoing Randomized Intervention with CPAP in Coronary Artery Disease and Sleep Apnea (RICCADSA) trial.

Although the study is on-going, he acknowledged, he also stated “analyses of baseline demographics and comorbidity profiles continue to strongly support OSA as a risk factor for CAD.” The study was started in 2005 to analyze the impact of continuous positive airway pressure (CPAP) on patients who had undergone revascularization for CAD and who also had OSA. ”Not only is the prevalence of OSA ‘surprisingly high,’” Dr. Peker said, but "these patients do not always show typical symptoms such as sleepiness.“

OSA was found in 64% of those with CAD. Comparitively, 58% had hypertension, and 28% were obese, making OSA much more common that was before thought of as more “conventional” risk factors. In addition, CAD patients with OSA were older than those without, were more obese, we mostly male, and had higher incidents of hypertension, diabetes, and atrial fibrillation.

Dr. Peker looked at both OSA syndrome (or "sleepy OSA," because of daytime sleepiness symptoms) and "nonsleepy OSA." He found that the CAD risk increase was present with both types of OSA.
The good news seems to be that those CAD patients that were studied with OSA had better compliance to the CPAP treatment. Dr. Peker indicated, “if we ask the CAD patients to use CPAP so far, they appear motivated enough to follow treatment.” At this point there is no proof that CPAP treatment actually reduces the risk for cardiovascular disease, however Dr. Peker suggested that it should be thought of as a “secondary cardiovascular prevention method.” The final results of the study are due out in 2012.

European Respiratory Society (ERS) 2010 Annual Congress: Abstract 5374. Presented September 22, 2010.