Sleep apnea is associated with many serious health risks, including heart disease and cancer. Now new research suggests it may damage your liver as well.
Morbidly obese patients with sleep apnea have a high risk for non-alcoholic fatty liver disease (NAFLD), but until now no one has known whether that’s because both are effects of obesity or if sleep apnea actually contributes to the risk of NAFLD.
A new study reveals, however that sleep apnea may increase your risk of NAFLD sevenfold.
What Is NAFLD?
The liver helps your body process nutrients and energy from your food and, along with the kidneys, helps filter your blood. NAFLD is a condition in which fat accumulates in the liver cells, which is known as steatosis. As the liver swells, it may begin to develop scars, which we call fibrosis in its early stages and cirrhosis in later stages. If cirrhosis gets bad enough, liver function is impaired and the liver may fail.
Most people with NAFLD don’t report symptoms until the condition is serious. Common symptoms include fatigue, loss of appetite, and abdominal pain, which some people may ignore or attribute to other conditions, further delaying treatment.
Sleep Apnea and NAFLD
In this new study, researchers tried to separate the risk of NAFLD for obese individuals who either had or did not have daytime sleepiness (used as a stand-in for sleep apnea). They evaluated sleepiness using two common tools, the Berlin Questionnaire (BQ) and the Epworth Sleepiness Scale (ESS). They compared the incidence of steatosis and fibrosis between individuals with or without daytime sleepiness.
They found that daytime sleepiness was correlated with a NAFLD risk 7.1 times higher than for those without daytime sleepiness.
Limitations of the Study
It’s important to know that sleep apnea may also result in liver damage, but it’s also good to remember that this study is very preliminary and takes a few shortcuts. For example, the study doesn’t actually compare people with sleep apnea and those without sleep apnea, it looks at daytime sleepiness using questionnaires. The BQ and ESS are both good preliminary tools for identifying people who should be tested for sleep apnea, but they don’t stand in for an actual sleep test.
The study also has a pretty small sample size, which limits the validity of the data. They only had 13 individuals who were positive on both the BQ and the ESS. The results do show a higher risk with daytime sleepiness, but if you look at the 95% confidence interval (a statistical range that shows we’re 95% sure the actual risk is somewhere in the range), it’s very large, from 1.7 to 51.
With such a large range, we’re not really sure whether this is a large risk or a small one.
Still, liver disease is another good reason why you should talk to your doctor (or a sleep dentist) about sleep apnea. To learn more call the TMJ Therapy & Sleep Center of Colorado at (303) 691-0267.