New Study Refutes Earlier Link Between Obstructive Sleep Apnea and Cancer

Obstructive sleep apnea (OSA) is a condition that causes a person’s airways to become obstructed, often requiring interruption of sleep in order to regain normal breathing. A person can have as many as thirty of these obstruction events an hour, restricting blood flow and causing a buildup of carbon dioxide. Around 18 million Americans have been diagnosed with sleep apnea.

The unique conditions created by constantly interrupted airflow and sleep can create a cascade of negative effects on the body, making the long-term effects of sleep apnea a subject of recent intense study.

Medical studies have discovered links between OSA and pneumonia, chronic fatigue, and heart disease, but one of the correlated effects can now be crossed off of the list: cancer. 

Reversing an Earlier Finding

An earlier study conducted several years ago in Spain found that people with OSA who experienced a drop in their blood-oxygen levels during sleep – a condition known as hypoxaemia – were at a much higher risk of cancer mortality or advancement than those without OSA or regular incidence of hypoxaemia.

The Spanish study came under some scrutiny, however, because of its small sample size and a potential measuring bias.

A newer study published in the Canadian Medical Association Journal combined information from over 10,000 patients’ data who had already undergone a long-term sleep study anywhere from 1994-2010. The researchers also cross-referenced materials from databases belonging to health administrations from the period of 1991-2013.

The results determined that there was not a statistically strong correlation between cancer growth and OSA. Over the average observed span of 7.8 years, only 6.5% of the participants who had not been previously diagnosed with cancer developed it during the period.

Thus a strong causal link could not be argued given the limited amount of clear data.

Hypoxaemia and Cancer

Medical experts had theorized that the conditions created by hypoxaemia during an OSA episode because the low-oxygen environment would stimulate blood vessel growth at the expense of eliminating pre-existing pathogens such as tumor cells. This activity could potentially allow cancer cells to metastasize.

Researchers involved in the study still speculate that hypoxaemia could still have a potential link to smoking-related cancers, but that the mechanisms are still difficult to determine.

The advancement of incidental cancer for patients within the study was not well-documented, leaving out vital data such as how advanced the cancer was and what the applied treatment was. This ambiguity could lead to unseen variables within the data. 

Treating Obstructive Sleep Apnea

While OSA might not have a strong link to cancer anymore, it can still be a major cause for concern. Waking up while choking and gasping is the surest sign, but many times these episodes are forgotten about or ignored considering the half-conscious nature during them.

The only way to accurately diagnose sleep apnea is to undergo overnight observation as part of a “sleep study,” allowing medical professionals to monitor your vital signs and physical activities during sleep.

OSA is commonly treated with positive airway pressure devices such as a CPAP machine. Other standard options range from using simple nasal decongestant and losing weight to oral surgery.

Restoring normal sleep patterns is vital to the body’s ability to recuperate and fight off infection, making OSA a serious cause for concern.