Severe obstructive sleep apnea (OSA) that is not treated with continuous positive airway pressure (CPAP) appears to be associated with cardiovascular death in the elderly, according to Spanish research. When compared with a control group, those with untreated severe OSA had a hazard ratio of 2.25 for cardiovascular mortality, compared with 0.93 for those treated with CPAP and 1.38 for those with untreated mild to moderate OSA.

Abstract: American Journal of Respiratory & Critical Care Medicine, November 1, 2012.