Sleep Apnea and Liver Enzymes: What’s the Connection?

Written By Abel Tamirat, MD

Published OnJuly 15, 2025

Sleep Apnea and Liver Enzymes: What’s the Connection?

If you've been diagnosed with sleep apnea or discovered elevated liver enzymes in your recent blood test, you might be surprised to learn the two conditions are often connected. Sleep apnea doesn’t just disrupt your breathing at night—it can quietly damage organs, including the liver.

In this in-depth guide, we’ll explore the link between sleep apnea and liver enzymes, explain how this relationship works, review the research, and outline proactive steps you can take to monitor and support your liver health, especially if sleep apnea is part of the picture.

What Is Sleep Apnea?

Sleep apnea is a condition where breathing stops and starts repeatedly during sleep. These interruptions—called apneas—can last for seconds or longer and may occur dozens or even hundreds of times a night.

There are two main types:

Obstructive Sleep Apnea (OSA): This is caused by the relaxation of throat muscles that block the airway
Central Sleep Apnea (CSA): due to the brain failing to send proper signals to the breathing muscles

The most common type is obstructive sleep apnea.

What are the Symptoms of Sleep Apnea?

Loud, chronic snoring
Gasping or choking during sleep
Excessive daytime fatigue
Difficulty concentrating
Headaches, especially in the morning
Mood changes, such as irritability

Sleep apnea can significantly impact cardiovascular health, blood sugar regulation, weight, and—as we’ll explore in this article—liver function.

What Are Liver Enzymes?

The liver produces several enzymes that help with metabolism, detoxification, and digestion. When liver cells become inflamed or damaged, they release these enzymes into the bloodstream.

Key Liver Enzymes to Monitor

ALT (Alanine Aminotransferase): Indicates liver cell injury
AST (Aspartate Aminotransferase): Present in liver and other organs
ALP (Alkaline Phosphatase): Reflects bile duct or liver issues
GGT (Gamma-Glutamyl Transferase): Often elevated with liver disease or alcohol use

High levels of these enzymes can point to liver inflammation, fatty liver disease, or other types of hepatic dysfunction.

Can Sleep Apnea Cause Elevated Liver Enzymes?

Yes. There is a growing body of evidence in research linking sleep apnea, especially moderate to severe obstructive sleep apnea, with elevated liver enzymes and liver inflammation.

How Sleep Apnea Affects the Liver

1. Intermittent Hypoxia:
Sleep apnea causes repeated oxygen deprivation (hypoxia) at night. This triggers oxidative stress in the liver, leading to inflammation and cellular damage, which results in elevated ALT and AST levels.

2. Systemic Inflammation:
OSA is known to increase inflammation throughout the body, including the liver. Over time, this can accelerate liver fibrosis and impair liver function. OSA contributes to liver fibrosis and long-term hepatic dysfunction.

3. Insulin Resistance and Fatty Liver Disease:
Many individuals with sleep apnea also have insulin resistance, a driving factor in non-alcoholic fatty liver disease (NAFLD). This condition leads to fat buildup in the liver and is closely associated with abnormal liver enzyme levels.

4. Obesity and Metabolic Syndrome:
Sleep apnea is more common in individuals with central obesity and metabolic syndrome—both of which also increase the risk of liver disease.

What the Research Says

Multiple studies support a connection between sleep apnea and liver enzyme elevation:

A 2020 study in Liver International reported that individuals with moderate to severe OSA had significantly higher levels of ALT and AST, even when controlling for body mass index (BMI) and alcohol use.
The Journal of Hepatology found that the severity of oxygen desaturation during sleep strongly correlates with liver fibrosis scores in patients with NAFLD.
Pediatric research shows that children with OSA may already have liver enzyme abnormalities, suggesting that the connection starts early.

These findings point to a clear conclusion: sleep apnea can independently contribute to liver damage, even without alcohol use or hepatitis.

Can Treating Sleep Apnea Lower Liver Enzymes?

Yes, treatment for sleep apnea—particularly CPAP therapy (Continuous Positive Airway Pressure)—has been shown to lower liver enzyme levels and reduce systemic inflammation.

How CPAP Helps:

Maintains steady oxygen levels during sleep
Reduces nighttime stress on the liver
Improves metabolism and supports weight loss
May slow or reverse progression of NAFLD

In studies, patients who used CPAP regularly experienced a significant decrease in ALT levels and improved liver ultrasound findings compared to those who did not adhere to treatment.

How to Know if You Have Elevated Liver Enzymes

Most people don’t experience symptoms when liver enzyme levels are mildly elevated. That’s why routine blood tests—including a Liver Function Test (LFT)—are critical, especially if you have known risk factors like sleep apnea.

You can get this done through your doctor or using a home liver test kit.

Signs That May Suggest Liver Involvement:

Fatigue or weakness
Mild upper right abdominal discomfort
Yellowing of skin or eyes (jaundice)
Dark urine or light-colored stool
Itchy skin
Unexplained weight gain

If you already have a diagnosis of sleep apnea and any of these symptoms are present, it's worth checking your liver health.

You can also try a simple at-home liver test kit.

Liver Conditions Linked to Sleep Apnea

Sleep apnea doesn't just trigger elevated enzymes. It’s also associated with more serious liver conditions:

1. Non-Alcoholic Fatty Liver Disease (NAFLD)

NAFLD is the most common liver condition linked to sleep apnea. Fat accumulates in the liver, leading to inflammation and elevated enzymes. If untreated, NAFLD can progress to more severe conditions.

2. NASH (Non-Alcoholic Steatohepatitis)

This is a more serious stage of NAFLD where inflammation and liver cell damage are present. It may eventually lead to cirrhosis.

3. Liver Fibrosis and Cirrhosis

Advanced liver scarring, often silent, can develop with long-standing inflammation. Sleep apnea, particularly in those who are obese or insulin resistant, increases this risk.

Learn more: Can liver function tests be normal with cirrhosis?

Who Is Most at Risk?

You are at greater risk of having both sleep apnea and liver enzyme elevation if you:

Are overweight or have central obesity
Have type 2 diabetes or insulin resistance
Drink alcohol regularly
Have high blood pressure or cholesterol
Are male or postmenopausal
Snore or feel tired despite sleeping 7–9 hours
Have metabolic syndrome

Having any two of these risk factors makes it wise to evaluate your liver and sleep health together.

Supporting Your Liver if You Have Sleep Apnea

1. Use Your CPAP Every Night

CPAP therapy is highly effective. Inconsistent use, however, reduces its protective effect on the liver.

2. Maintain a Healthy Weight

Losing just 5–10% of your body weight can significantly improve both sleep apnea and liver enzyme levels.

3. Limit Alcohol and Processed Foods

Excess alcohol and high-sugar foods exacerbate liver stress and inflammation.

4. Get Regular Liver Function Tests

Monitoring your levels allows for early detection and course correction. Consider using a home liver enzyme test.

5. Consider Nutritional Support

Some supplements have shown promise in supporting liver health. These include:

Omega-3 fatty acids
Vitamin E (under medical supervision)
Milk thistle extract

Natural Strategies to Improve Sleep Apnea

Even with CPAP or other treatments, lifestyle changes can help reduce the severity of sleep apnea.

Elevate the head of your bed
Avoid heavy meals or alcohol before sleep
Sleep on your side
Engage in regular exercise
Avoid sedatives and sleeping pills unless prescribed
Practice nasal breathing

Supportive nutrition may help too. Learn more: Is melatonin bad for your liver?

Final Thoughts

The connection between sleep apnea and liver enzymes is real—and important to understand. Left untreated, sleep apnea doesn’t just disrupt your rest—it can also contribute to long-term liver injury.

The good news is that both conditions are highly manageable. By recognizing the signs, getting proper screenings, and implementing supportive lifestyle habits, you can protect your liver, sleep better, and improve your overall well-being.

You can start with our simple at-home testing options!

Curious how your liver is doing? Explore Ribbon Checkup’s at-home liver tests for simple, lab-quality insights you can trust.

Related Resources

References

Ahmed, M. H. (2010). Obstructive sleep apnea syndrome and fatty liver: Association or causal link? World Journal of Gastroenterology, 16(34), 4243–4243. https://doi.org/10.3748/wjg.v16.i34.4243

Clinic, C. (2023, September 5). Elevated Liver Enzymes: What Is It, Causes, Prevention & Treatment. Retrieved July 10, 2025, from Cleveland Clinic website: https://my.clevelandclinic.org/health/symptoms/17679-elevated-liver-enzymes

Haruka Hirono, Watanabe, K., Hasegawa, K., Masaki Kohno, Terai, S., & Shogo Ohkoshi. (2021). Impact of continuous positive airway pressure therapy for nonalcoholic fatty liver disease in patients with obstructive sleep apnea. World Journal of Clinical Cases, 9(19), 5112–5125. https://doi.org/10.12998/wjcc.v9.i19.5112

Mirrakhimov, A. E., & Polotsky, V. Y. (2012). Obstructive Sleep Apnea and Non-Alcoholic Fatty Liver Disease: Is the Liver Another Target? Frontiers in Neurology, 3. https://doi.org/10.3389/fneur.2012.00149

Parikh, M. P., Gupta, N. M., & McCullough, A. J. (2019). Obstructive Sleep Apnea and the Liver. Clinics in Liver Disease, 23(2), 363–382. https://doi.org/10.1016/j.cld.2019.01.001

Sheng, W., Ji, G., & Zhang, L. (2022). Management of non-alcoholic fatty liver disease patients with sleep apnea syndrome. World Journal of Gastroenterology, 28(43), 6099–6108. https://doi.org/10.3748/wjg.v28.i43.6099

Sleep apnea - Symptoms and causes. (2025). Retrieved July 10, 2025, from Mayo Clinic website: https://www.mayoclinic.org/diseases-conditions/sleep-apnea/symptoms-causes/syc-20377631

Written by Abel Tamirat, MD

Dr. Abel Tamirat is a licensed General Practitioner and ECFMG-certified international medical graduate with over three years of experience supporting U.S.-based telehealth and primary care practices. As a freelance medical writer and Virtual Clinical Support Specialist, he blends frontline clinical expertise with a passion for health technology and evidence-based content. He is also a contributor to Continuing Medical Education (CME) programs.

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