Two Studies Could Link Sleep Apnea to Cancer
Recent research has uncovered a possible link between sleep apnea and cancer. Two studies in an article posted May 20, 2012 on The New York Times website indicate that sleep apnea sufferers have a greater risk of developing cancer.
Approximately 28 million Americans have sleep apnea. This is a disorder that causes a person to stop breathing for short periods during sleep. In one of the studies, Dr. Miguel Angel Martinez-Garcia of La Fe University and Polytechnic Hospital in Spain said sleep apnea patients who use a CPAP breathing device might have less of a risk of cancer.
The study that involved Martinez-Garcia and headed by the Spanish Sleep Network found that subjects whose oxygen levels dropped below 90 percent for up to 12 percent of their sleep time were 68 percent more likely to develop cancer than people whose oxygen levels remained normal throughout the night.
Over a seven-year period, this study tracked around 5,200 people. None of the people had cancer at the beginning of the study. Researchers used the hypoxemia index to discover how long during sleep a subject’s oxygen level dropped below the 90-percent threshold.
The other study, conducted at the University of Wisconsin School of Medicine and Public Health found that the severity of a person’s breathing difficulties during sleep was tied to their likelihood of them dying of cancer.
Using data from the Wisconsin Sleep Cohort, a sleep study begun in 1989, researchers determined that people with moderate sleep apnea die of cancer twice as often as those with no breathing problems. Patients whose sleep apnea was severe were 4.8 percent more likely to die of cancer than individuals without sleep apnea.
“Apnea” means “a pause in breathing”. Patients with sleep apnea can stop breathing for a few seconds to more than a minute. The pauses can happen as many as 30 times or more in an hour. There are three forms of sleep apnea: central sleep apnea, constituting less than half of one percent of all cases; obstructive sleep apnea, which affects 84 percent of cases; and complex or mixed sleep apnea, which accounts for about 15 percent of cases.
Because the patient normally is not aware of the condition, he may suffer for years before seeking treatment. While sleep apnea does produce symptoms such as lethargy, a slow reaction time, and visual disturbances, many people do not connect these problems with a larger underlying disorder.
Often a spouse will be the one to notice his or her partner’s irregular breathing patterns. Snoring is another indicator that a person could have sleep apnea. Once a person believes he may have this disorder, their physician will perform extensive tests. Most likely, the doctor will order a sleep study.
Dr. F. Javier Nieto, who talked about the results at the American Thoracic Society’s 2012 International Conference in San Francisco, headed the University of Wisconsin School of Medicine study.
“Clearly, there is a correlation, and we are a long way from proving that sleep apnea causes cancer or contributes to its growth,” Nieto was quoted on May 20 in the Toronto Sun. “But animal studies have shown that the intermittent hypoxia [an inadequate supply of oxygen] that characterizes sleep apnea promotes angiogenesis – increased vascular growth – and tumor growth.”
This connection further solidifies the need to be tested for sleep apnea. With new in-home sleep apnea tests, the process is becoming much easier and cheaper. If you suspect you have sleep apnea, contact your doctor about having a sleep test.
Bio: Chris Vasta is the Vice President of Agile Medical, LLC., a leading provider of CPAP machines. Please browse our site to learn more about the CPAP machines we offer, as well as our masks and accessories.