According to the National Institutes of Health, obstructive sleep apnea (OSA) affects more than twelve million Americans. Learn what recent medical studies have uncovered about OSA’s association with compromised liver function.
While a sleep disorder may appear to have nothing to do with liver health, their association proves that a holistic perspective should never be dismissed. Holistic medicine revolves around looking at and considering an entire person’s health for the purpose of diagnosis and treatment planning.
The Greek word “apnea” literally means “without breath.” There are three types of sleep apnea:
- Obstructive – Caused by a blockage of the airway, this typically occurs when the soft tissue in the rear of the throat collapses and closes during sleep.
- Central – The airway is not blocked, but the brain fails to signal the respiratory muscles to breathe.
- Mixed – As the name implies, mixed apnea is a combination of obstructive and central apneas.
Of the three, obstructive sleep apnea is the most common. Despite the difference in the root cause of each of the three, those with any type of untreated sleep apnea stop breathing repeatedly during sleep, sometimes hundreds of times during the night and often for a minute or longer. With each apnea event, the brain briefly rouses the person awake in order for them to resume breathing. This arousal creates poor quality sleep and eventually results in endless fatigue.
Risk and Consequence
Although sleep apnea can strike anyone at any age, high risk factors include being male, overweight and over the age of forty. Due to the lack of awareness by the public and healthcare professionals, many people with sleep apnea remain undiagnosed and untreated, despite the fact that this disorder can have significant consequences.
In addition to causing high blood pressure and other cardiovascular diseases, sleep apnea results in memory problems, weight gain, impotency, headaches, and if left untreated, may contribute to liver disease. Fortunately, once sleep apnea is diagnosed, several types of treatment are currently available, with more on the horizon.
The Liver Connection: French study
According to French researchers, severe OSA is a risk factor for elevated liver enzymes and steatohepatitis. This conclusion is independent of the individual’s body weight. Capable of progressing to advanced liver disease, steatohepatitis is the accumulation of fat in the liver accompanied by hepatic inflammation. For more information on fatty liver disease, read the previous article, How to Prevent a Fatty Liver. While being overweight goes hand in hand with both OSA and liver disease, researchers claim sleep apnea may directly cause liver disease regardless of weight. According to this French study, overweight people with sleep apnea had a higher risk of disease than those without.
Dr. Lawrence Serfaty and colleagues evaluated 163 consecutive, non-alcoholic patients referred to the Sleep Unit at Hospital Saint-Antoine in Paris for evaluation of suspected OSA. The researchers uncovered the following information from those with sleep disorders:
- Severe OSA was found in 27 percent of the patients.
- Moderate OSA was found in 52 percent of patients.
- Patients with severe OSA were more insulin resistant (a risk factor for liver disease) and more likely to have liver damage than people of the same weight who didn’t have the sleep disorder.
At this time, it is unclear if insulin resistance is directly related to OSA, or if apnea’s lack of oxygen is the responsible for the correlation between liver disease and obstructive sleep apnea. Regardless of the causes, this connection serves as a warning to those with sleep disorders to investigate their liver health further.
The Liver Connection: Canadian study
Researchers at the University of Manitoba investigated the occurrence of obstructive sleep apnea symptoms in people with diagnosed non-alcoholic fatty liver disease (NAFLD).
NAFLD describes two conditions that affect people who drink little or no alcohol. The first is a mild condition, while the second is its progression to a more severe disease.
- Fatty liver, also known as steatosis, is an accumulation of fat in the liver that typically does not cause liver damage.
- Nonalcoholic steatohepatitis (NASH) is the accumulation of fat in the liver accompanied by hepatic inflammation. Fibrous tissue can form with NASH, which can progress to cirrhosis or liver cancer.
Both conditions are reported to occur with insulin resistance, a risk factor for both diabetes and liver disease.
The results of the Canadian investigation showed approximately 50 percent of people with NAFLD, regardless of the severity, demonstrated symptoms of obstructive sleep apnea. Again, while further studies are required to determine whether a causal link exists between NAFLD and OSA, these results indicate a significant correlation between liver disease and sleep apnea.
What Does This Mean?
The implications of OSA’s liver disease connection could dramatically affect individuals with sleeping disorders or with liver disease. The evidence suggests taking the following action:
- People with liver disease and a sleeping problem should be evaluated for OSA, since treatment options for OSA exist.
- Someone with OSA may wish to check the health of their liver due to the significant correlation between sleep apnea and liver disease.
The more information gathered about the far reaches of liver disease, the deeper our understanding is of this monumental problem. As western medical establishments document an increasing number of connections between various body systems, they are unknowingly supporting a holistic health view. The relationship between sleep apnea and liver disease is another example of mainstream medicine’s acknowledgement that our entire body is interconnected, and what affects one system will likely affect all of our systems.
www.mercola.com, Sleep Problems Can Ruin Your Health and Shorten Your Life, Dr. Joseph Mercola, 2006.
www.ncbi.nlm.nih.gov, Chronic Liver Injury during Obstructive Sleep Apnea, Tanne F, Gagnadoux F, Chazouilleres O, Fleury B, Wendum D, Lasnier E, Lebeau B, Poupon R, Serfaty L, Hepatology, June 2005.
www.ncbi.nlm.nih.gov, Symptoms of obstructive sleep apnea in patients with nonalcoholic fatty liver disease, Singh H, Pollock R, Uhanova J, Kryger M, Hawkins K, Minuk GY, Dig Dis Sci. December, 2005.
www.sleepapnea.org, Sleep Apnea Information, American Sleep Apnea Association, 2006.