Did you know that not getting enough oxygen into your lungs at night can exacerbate non-alcoholic fatty liver disease?
Scientists have confirmed that obstructive sleep apnea worsens liver disease. Studies linking sleep apnea with liver damage point to oxidative stress as the real culprit of liver cell injury. In addition, obstructive sleep apnea (and fatty liver disease) commonly occurs in obese individuals – rendering weight management solutions a priority. Thus, efforts to minimize oxidative stress and prevent or reverse obesity constitute critical components of stopping liver disease progression.
About Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) describes the condition of a sleeper’s airway collapsing, causing breathing to stop and then restart abruptly. The repeated interruptions in breathing throughout the night cause low blood oxygen levels, known as hypoxia, and have been linked to heart disease and stroke. OSA is the most common form of sleep apnea and occurs when the muscles in the back of the throat relax.
7 Symptoms of Obstructive Sleep Apnea
- Loud snoring
- Breathing cessation during sleep
- Waking with a dry mouth or sore throat
- Morning headache
- Difficulty staying asleep
- Excessive daytime sleepiness
- Attention problems and irritability
People who are obese have four times the risk of sleep apnea than those of a normal weight. Fat deposits around the upper airway may contribute to breathing obstruction. However, not everyone who has sleep apnea is overweight. Other risk factors include having a large neck circumference, a narrow airway, family history of OSA, use of alcohol, sedatives or tranquilizers, smoking and nasal congestion.
Mild cases of sleep apnea typically warrant lifestyle changes such as weight loss and smoking cessation. Other treatments can range from medications for nasal allergies, to a sleep-time mask that delivers air pressure, to surgical intervention.
About Fatty Liver Disease
Non-alcoholic fatty liver disease (NAFLD) describes the accumulation of fat in the liver of people who drink little to no alcohol. In some people, the accumulated fat causes inflammation and scarring in the liver, resulting in a more serious form of the disease called non-alcoholic steatohepatitis (NASH).
Rates of non-alcoholic fatty liver disease are skyrocketing, with an estimated 30 to 40 percent of American adults and nearly 10 percent of children impacted. NAFLD is associated with obesity, insulin resistance and Type 2 diabetes. The early stages of NAFLD do not pose any major health threats, but progression to NASH can lead to severe liver fibrosis, cirrhosis and liver cancer.
Non-alcoholic fatty liver disease and obstructive sleep apnea frequently affect people who are overweight or obese – and often go undiagnosed. Several studies suggest that NAFLD and OSA are linked – and that sleep apnea has a causal relationship to fatty liver disease progression.
The Connection Between NAFLD and OSA
A growing number of studies are demonstrating a link between sleep apnea and the worsening of liver disease – especially NAFLD. Obstructive sleep apnea hampers the amount of oxygen that reaches the bloodstream during the night. This low blood oxygen level results in oxidative stress. Researchers suspect that oxidative stress at night – when the majority of cellular restoration occurs – is the primary culprit in liver disease progression.
- A study published in the June 2005 edition of the journal Hepatology evaluated 163 people with obstructive sleep apnea. They found a significantly higher percentage of fatty liver disease in the most severe apnea cases.
- In a March 2014 edition of the journal Chest, researchers evaluated 226 obese middle-aged men and women who were suspected of having sleep apnea. They found that two-thirds had fatty liver disease, and that the severity of the disease increased with the severity of their sleep apnea.
- Published in an April 2014 edition of The Journal of Pediatrics, researchers identified sleep apnea in 60 percent of young subjects with fatty liver disease. The worse their apnea episodes, the more likely they were to have fibrosis, or scarring of the liver.
Though the mechanism has not yet been proven, doctors suspect that the loss of oxygen from sleep apnea is the primary culprit for liver injury. Low oxygen levels increase chronic inflammation, which worsens fatty liver disease. The data from these studies show that impairment of breathing during nighttime is a trigger of oxidative stress – which promotes the progression of non-alcoholic fatty liver disease. These individuals have a greater imbalance between the production of free radicals and their body’s ability to counteract their harmful effects than subjects without OSA and low oxygen.
There is no singular solution for the problems associated with obesity, obstructive sleep apnea and non-alcoholic fatty liver disease. However, strategies that help people maintain or achieve an ideal weight, improve nighttime oxygen levels in those with OSA and minimize oxidative stress help ease this multi-faceted problem.
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