HOUSTON - Most all of us have experienced a restless night, tossing and turning, waking up so many times we can't remember. Chronic insomniacs have it the worst. And that stress on the body increases the risks for all sorts of things -- high blood pressure, heart attack, and stroke to name a few. These days, cancer is also entering the conversation as a risk factor.
There have been a few studies this year suggesting an association between poor sleep and an increased risk for cancer. In one, women working the night shift for multiple years showed an increased risk of breast cancer. Another looked at patients with severe sleep apnea and found a 65 percent increased risk for cancer of any kind. There was also a big study from The University of Wisconsin School of Medicine and Public Health in which people with severe untreated sleep apnea were almost five times more likely to die from cancer.
We asked Neurologist Todd Swick, medical director of Apnix Sleep Diagnostics in Houston, about the theory behind this new research and the association between sleep apnea and an increased risk for cancer.
"One of the things that happens during sleep apnea is your oxygen drops," Dr. Swick said. "One of the body's reactions to that drop in oxygen is to stimulate the production of new blood vessels [and] that process has been implicated in the formation, the elaboration of growth, of tumors."
Dr. Swick said it's not necessarily that sleep apnea is causing cancer, only that the effects of sleep apnea on the body produce conditions favorable to the growth of tumors.
In 2011, while reporting on a different story, Dr. Swick partially wired-up KPRC Local 2 anchor Owen Conflenti at the sleep center. Conflenti learned he had issues with snoring. But Confenti also showed signs that his breathing stopped while falling asleep. Snoring and that kind of disruption in breathing are two tell-tale signs of possible sleep apnea.
"If you take 100 people who snore," said Dr. Swick, "about two-thirds will have significant sleep apnea."
That equals about 18 million people in this country according to health experts. Beyond that, another 10 million people may not know they have sleep apnea.
For Conflenti's official sleep study, Dr. Swick took dozens of measurements overnight; how long he actually slept (8.6 hours); how many times he woke up (47); how many times he kicked or moved a limb (53). But the most important measurements in the search for signs of sleep apnea were in Conflenti's breathing patterns and oxygen levels.
Dr. Swick was looking for periods during the night when Conflenti's oxygen dropped to what he considers significant or critical levels. In the end, the results were completely normal. Despite the earlier symptoms (including snoring) of sleep apnea, the sleep study showed otherwise. But Dr. Swick also reminded Conflenti that this is only one snapshot of life now and that the condition can change. Without maintaining good health, Dr. Swick says sleep apnea can develop down the road, which, in turn, could expose the body once again to an increased risk for cancer.
"I'd much rather treat the sleep apnea when somebody's in their 20s and 30s than have to deal with the stroke heart attack and cancer when they're in their 40s and 50s," said Dr. Swick.
So next time that friend or loved one snores so loudly it wakes you up, take a mental note of their breathing pattern before giving them the elbow.
For those who sleep alone and are wondering if they have signs of sleep apnea, Dr. Swick suggests a voice-activated audio recorder that begins recording with the presence of sound to catch yourself snoring at night. Local 2 found some products online for under $25. There is also software, often marketed under "home security," that will use your laptop's built-in camera and microphone to monitor you while you sleep and record when triggered by motion or sound.
Conflenti has used EvoCam for the Mac and found those products worked well. Regardless of the method, what's important are the results.
Dr. Swick says, "If the snoring is interrupted with pauses [in breath], you better get yourself to the doctor."
Department Of Population Health Sciences, University Of Wisconsin School Of Medicine And Public Health:
Institute Of Cancer Epidemiology At The Danish Cancer Society In Copenhagen:
La Fe University and Polytechnic Hospital, Valencia, Spain: