The Link Between Sleep Apnea and Cancer—Evidence is Mounting

September is back to school month for many of our children — it’s also a good time for adults to learn about health issues, so here is some information to help you become educated about the health risks associated with untreated sleep apnea. Evidence is mounting: severe obstructive sleep apnea (OSA) may be linked to a higher risk of dying from cancer.

The results of three recent studies in Spain were presented in early September at the European Respiratory Society’s (ERS) Annual Congress in Vienna. The data presented by the Spanish researchers reinforces the results of previous studies which show similar links between severe OSA and cancer death. 

While scientists have yet to prove 100% that sleep apnea causes a higher risk of cancer death, more and more studies are showing the link. When obstructive sleep apnea occurs, a person’s airway becomes obstructed during sleep, blocking air flow and causing the person to wake suddenly, often gasping for air. This can happen hundreds of times a night, causing a person’s blood oxygen level to drop abnormally low.

Many researcher theorize that the lack of adequate oxygen supply, known as intermittent hypoxia, caused by OSA causes increased vascular growth and tumor growth because poor breathing fails to oxygenate the cells sufficiently.

Thankfully, people with sleep apnea can be treated using multiple methods. One of the most effective is continuous positive airway pressure (CPAP) therapy, which generates a stream of air to keep the upper airways open during sleep.

Let’s look at some recent sleep apnea and cancer studies out of Spain. Dr. Miguel Angel Martinez-Garcia from La Fe University Hospital in Valencia, Spain, and his fellow researchers studied more than 5,600 sleep apnea patients from seven different sleep clinics in Spain. The researchers measured the severity of a patient’s sleep apnea, based on the number of times during the night that a patient’s blood oxygen level dropped below 90 percent oxygen saturation.

The results of the study showed that people with sleep apnea who spent more than 14 percent of their sleep time with oxygen saturation levels below 90 percent not only had severe sleep apnea, but were approximately double the relative risk of dying due to cancer than people without sleep apnea. The researchers also found a significant increase in the relative risk of dying from cancer in people with less severe sleep apnea. This association was even higher in men and younger people.

Lead researcher Dr. Martinez-Garcia stated that the results do not mean unequivocally that sleep apnea causes cancer—it means the researchers found an association between the two disorders. However, the results of the experiment add to growing evidence that there is a clear link between sleep apnea and cancer mortality. 

Research from two other Spanish studies presented at the European Respiratory Society’s Annual Congress showed an increase in cancer incidence in humans, as well as an association between sleep apnea and the spread of cancer in mice.

The second study showed an increase in all types of cancer in people with severe sleep apnea, even when other factors such as age, sex and weight were taken into account. In a third study, Spanish researchers used mice to study the spread of melanoma skin cancer, and whether this was associated with sleep apnea.

The results showed that the spread of cancer was more abundant in mice that had experienced low levels of oxygen as in sleep apnea, than those who breathed normal air during the experiment.

According to the study’s lead author, Professor Ramon Farre from the University of Barcelona in Spain, the results of the mouse study strongly suggests a link between sleep apnea and the spread of cancer, and encourages further research to better understand the links between sleep apnea and cancer.

I agree with Professor Farre that these recent studies offer compelling evidence, and it is our responsibility in the medical and scientific communities to continue researching and testing to better understand the link between sleep apnea and cancer. 

Read the full study, Sleep Apnoea Linked with Increased Risk of Cancer Death.

Snoring a Problem? Try Losing Weight…

One of the most common factors that contribute to a person who snores is their weight. Typically, people who are obese have the most problems with respiratory symptoms during sleep. Even what seemingly may seem a small weight issue of 10-15 extra pounds may cause snoring. Although there are other factors that may contribute to snoring, if you’re overweight, weight reduction should be one of your chief goals.

To understand why, you must understand what physically causes snoring. During sleep, the throat relaxes and the tongue falls into the airway in the back of the throat causing a vibration in the soft tissue. Fatty tissue, chin folds and a very large neck, common in those that are overweight, are physical characteristics that can contribute to the snoring sound. Being overweight is linked to difficulties with snoring, regardless of any age. Weight reduction should be one of the chief goals of any overweight person who snores, because typically even the loss of a few pounds can reduce snoring.

However, there is no one solution to weight loss and management. There are vast differences in the human metabolism just as there are differences in anatomy. Weight loss programs are most successful when they combine a lower caloric intake with an exercise program. Since snoring can cause daytime fatigue, it’s often difficult at first for a snorer to get the energy up to start an exercise routine. With consistent effort, however, exercising can actually increase a person’s energy level throughout the day.

It is very important when beginning an exercise program, to start carefully and slowly at first because it is common for people to overdo it at first and become discouraged, or worse injured. It’s also important to get a green light from your physician first — he or she can start you on a program that is right for you.

You may find that you need to experiment with different approaches to dieting to discover what works best for you, since everyone’s metabolism is unique. Whichever approach you choose, commit to the long term for weight normalization, not just loss. The reason that most diets fail is that many dieters try to “force” weight off the body in an unhealthy or unnatural way. In other words, they focus on dropping pounds or losing weight rapidly, as opposed to normalizing their weight in a more natural way over a longer period of time. Sustaining a normal, healthy weight takes patience and a commitment to eating healthy and exercising regularly.

Weight loss reduces snoring in many people, sometimes stopping it completely. It also improves sleep and significantly reduces daytime sleepiness, allowing for a more productive waking day as well. To find out if your weight is a factor in your snoring, schedule an appointment today with the Manhattan Snoring and Sleep Center for an evaluation.