By Jim Sullivan, editor

BOSTON -- People with sleep apnea are more than twice as likely to die from cardiac arrest during sleeping hours than people without sleep apnea, according to study published in a March edition of the New England Journal of Medicine.

For the general population, the reverse is true. People without sleep apnea are more than twice as likely to die between 6 a.m. and noon than during sleeping hours.

The study's authors reached their conclusions after examining of the death certificates of 112 Minnesota residents who had had sleep studies at the Mayo Clinic Sleep Disorder Center between 1987 and 2003 and who died suddenly of cardiac causes. More than half (54%) of the 78 OSA patients died between 10 p.m. and 6 a.m., while only 24% of the 34 cardiac deaths among non-OSA patients occurred during that period.

The researchers could not tell whether the use of CPAP reduced the nocturnal death rate because utilization data was not available. However, the study notes that previous studies have shown that CPAP relieves symptoms of OSA and raises nighttime levels of oxygen in the blood.

While sleep therapists don't need a study to tell them that people with sleep apnea are more likely to die of heart failure at night, the NEJM study furthers the clinical case for apnea.

"One thing we're waiting for is the NIH or the CDC to say sleep disordered breathing is a chronic disease. No one has said as much yet," said Ron Richard, ResMed's vice president of marketing. "It's a chronic disease and it needs to be recognized as such. We need to treat it like COPD, asthma.