May 21, 2012
Snoring Could Be Deadly
Those with sleep apnea and a chronic snore may have an increased risk of cancer mortality, according to a new study to be presented at this year´s American Thoracic Society conference in San Francisco.
The culprit is sleep disordered breathing (or SDB), and those with this condition also face an increased risk of cardiovascular events and psychopathological outcomes as well.
"Sleep apnea is the periodic pausing of breathing during sleep that results in drops in oxygen levels in your blood. It causes snoring and sleepiness during the day," explained study author Dr. Javier Nieto, chair of the department of population health sciences at the University of Wisconsin School of Medicine and Public Health, in Madison, to HealthDay Reporter Serena Gordon.
"Aside from being an annoyance to your spouse, family members and maybe even your neighbors depending on how loud your snoring is, sleep apnea is a severe problem. Drowsiness and sleepiness during the day increase the risk of accidents, and sleep apnea is associated with cardiovascular disease, heart disease, strokes, hypertension and cardiovascular mortality. Now, we see this new angle: an increase in cancer mortality," Nieto told Gordon.
Dr. Nieto and his team analyzed mortality data from over a span of 22 years and 1,522 subjects from the Wisconsin Sleep Cohort study. According to a press release explaining the study, the team then made adjustments for age, sex, BMI, smoking and other factors. In the end, those with mild cases of sleep apnea–or 5 to 14.9 episodes of low-to-no oxygen in an hour–had a 10% increase of risk of cancer death. For those with moderate sleep apnea–15 to 29.9 episodes– their risk of cancer death more than doubled.
Finally, those with the worst cases of sleep apnea – or 30 episodes of low-to-no oxygen in an hour – had a 4.8 times higher risk of cancer mortality.
Though this study doesn´t prove a strong cause-and-effect relationship between SDB and cancer death, the research suggests the association is strong enough in both animals and humans.
Dr. Nieto credited researchers from the University of Barcelona, Spain for suggesting the link between SDB and cancer mortality. These researchers had discovered the link in mice that were periodically deprived of oxygen. According to their results, skin cancer tumors grew more rapidly without the presence of oxygen.
Dr. Nieto explains the behavior, saying that when the body goes through periods of low or no oxygen, the cancer cells will "try to compensate for the lack of oxygen by growing additional blood vessels to get more oxygen. It's a defense mechanism.” As these blood vessels grow, so too will the cancer cells.
Some sleep specialists aren´t surprised by these findings. According to the HealthDay, Dr. Steven Park responded to the results by saying, "This goes along with the link between sleep apnea and pretty much every chronic medical condition out there.”
Dr. Park also mentioned these results should be confirmed in future studies and published in a peer-reviewed journal.
"Anyone with snoring, severe daytime fatigue, lack of memory or focus, high blood pressure, diabetes, and even someone who has to get up to go to the bathroom at night should be screened,” he said.
If you get plenty of sleep at night but still feel tired during the day, Dr. Park suggests it´s time to get tested by your doctor.