Exploring the Link Between Sleep Apnea and Cancer

Recent studies have indicated demonstrable links between Obstructive Sleep Apnea, a condition that inhibits proper breathing during sleep, and increased risk for various types of cancer. Nearly twenty-eight Million Americans suffer from OSA, and there is no statistic for how many cases remain undiagnosed. Sleep apnea is a noteworthy condition for many doctors, as it has shown correlations with cardiovascular diseases, clinical obesity, and a host of other physical and psychological concerns.
While this link isn’t as strong or well documented as the correlation between sleep apnea and diabetes, it is another well founded reason for those afflicted with the disorder to seek proper treatment. One study, conducted by Spanish researchers, quantified data from several thousand patients engaged in sleep studies, and discovered a correlation between those that were afflicted with more severe forms of sleep disorder having as much as  a 65% increased risk of developing one type of cancer or another.

A subsequent study, detailed approximately 1,500 government employees in Wisconsin, and found that patients who reported having the most breathing disruptions during sleep were diagnosed with cancer at a rate of 5 times the number of those without sleep apnea. It’s important to note that researchers did not study specific types of cancer, only general oncological data.  Researchers for both studies adjusted for other typical cancer risk factors to minimize the possible tainting of data not directly attributed to sleep apnea.
Researchers discovered that the severity of a patient’s sleep apnea (among other breathing difficulties during sleep) shows a marked correlation to the likelihood of that person also being afflicted with cancer. Those studied with moderate sleep apnea were found to have fatal forms of cancer twice as frequently as those with no reported sleep apnea. Others, who fell into the severe category, were found to have fatal forms of cancer at more than twice that rate (nearly 5 times that of those without sleep apnea at all).

A second study looked at the incidence of cancer, rather than the mortality of it among sleep apnea patients using the hypoxemia index. The hypoxemia index examines the amount of time during sleep that a patient’s O2 level drops or stays below the 90% threshold while sleeping. Approximately five thousand people were studied for a seven-year period. It’s important to note that none of these participants had a cancer diagnosis of any kind at the initiation of the study. What researchers found was that cancer diagnoses of the study’s participants were inversely correlated to their oxygen levels; the lower the O2 blood saturation level, the higher the incidence of cancer. A disruption for as little as 12 percent of a patient’s total sleep time, showed a full 68 percent increased probability of a cancer diagnosis than those whose oxygen saturation did not fall below that 90% threshold at night.
It is also important to note that the study did not examine that effect of CPAP (Continuous positive airway pressure) therapy with regard to the cancer / sleep apnea link, but several researchers and doctors have posited that CPAP therapy is likely to decrease the chances of cancer development, since it counters the hypoxemia factor they were studying. They did note, however, that when patients on CPAP therapy were removed from the data, the cancer association did become stronger.
Bio: K. Leeds is a freelance writer for The CPAP Shop, one of the leading providers of CPAP machines and CPAP therapy.  Please visit The CPAP Shop website to learn more about their products and brands.