What is NAFLD?
Non-alcoholic fatty liver disease (NAFLD) is an umbrella term for a range of conditions caused by excess accumulation of fat in the liver. It is normal for the liver to contain around 5% – 10% percent fat of its weight. When more than 10% of the liver weight is fat, it is called a fatty liver (steatosis). The most common cause of fatty liver is alcohol consumption. The second common cause is obesity.
The causes of fatty liver other than alcohol and diabetes mellitus are obesity, high triglycerides, rapid weight loss, certain medications, and malnutrition.
The early-stage NAFLD does not cause any harm, but if it continues to progress, it can lead to irreversible liver damage called liver cirrhosis. Cirrhosis develops when the cells in the liver are replaced by fibrous tissue, causing a loss of liver function.
If detected and managed early, it’s possible to stop NAFLD from worsening and reduce the amount of fat in your liver.
What are the symptoms of non-alcoholic fatty liver disease (NAFLD)?
Usually, early NAFLD is symptomless. It is mostly an incidental finding.
The people with NASH or fibrosis (more advanced stages of NAFLD) may experience non-specific symptoms like tiredness, aches and pains, and mild jaundice.
If cirrhosis (the most advanced stage) develops, the patient may present with acute liver failure, itchy ascites, skin, and swelling in the legs, ankles, feet, or tummy (oedema).
What are the main stages of NAFLD?
The main stages of NAFLD are:
1. Simple fatty liver (steatosis) – a largely harmless build-up of fat in the liver cells that may only be diagnosed during tests carried out for another reason
2. Non-alcoholic steatohepatitis (NASH) – a more serious form of NAFLD, where the liver has become inflamed and the liver enzymes (transaminases) are raised. Some clinical signs like icterus may develop.
3. Fibrosis – where persistent inflammation causes scar tissue around the liver and nearby blood vessels, but the liver is still able to function normally.
4. Cirrhosis – the most severe stage, occurring after years of inflammation, where the liver shrinks and becomes scarred and lumpy; this damage is permanent and can lead to liver failure (where your liver stops working properly) and liver cancer
Since it can take years for fibrosis or cirrhosis to develop. It’s important to make lifestyle changes to prevent the condition from getting worse, especially as the changes may start as early as the twenties.
How non-alcoholic fatty liver disease (NAFLD) is diagnosed?
NAFLD is often diagnosed with a liver function test, though blood tests are not the gold standard for the diagnosis. It is often picked up in a routine USG done for other purposes. Some people may need a biopsy for the diagnosis. Children and young people with an increased risk of NAFLD (those with type 2 diabetes or metabolic syndrome) should have an ultrasound scan of their liver every 3 years.
How is non-alcoholic fatty liver disease (NAFLD) treated?
There’s currently no specific medication for NAFLD other than lifestyle choices. The treatment of co-existing comorbities like hypertension, DM, and hyperlipidemia also helps control the condition. No medicine is currently approved for NAFLD treatment. A Liver transplant is the final option in cases of terminal-stage liver disease.
Lifestyle modifications:
- Weight loss: The BMI is 18.5 to 24.9 (use the BMI calculator to work out your BMI); losing more than 10% of your weight can help halt NASH progression.
- Healthy diet: a balanced diet high in fruits, vegetables, protein, and complex carbohydrates, low in fat, sugar, and salt; as well as potion control.
- Hydration: Having water instead of sweet drinks, at least 2L a day unless contraindicated.
- Sweat: At least 150 minutes of moderate-intensity activity, such as walking or cycling, a week helps with managing fatty liver. All types of exercise can help improve NAFLD, even if you do not lose weight
- Stop smoking as well as alcohol consumption.
The ADA recommendations for managing NAFD (2023 update)
- No single dietary pattern is best for all people with type 2 diabetes, hence there is the freedom to individualize advice.
- Time-restricted eating (TRE) and intermittent fasting are supported by studies demonstrating a short-term weight loss of 3–8%, similar to that achieved with daily calorie restriction.
- The Mediterranean diet still has the strongest evidence for delaying progression to type 2 diabetes and for primary and secondary CVD prevention. There are long-term secondary CVD prevention benefits compared with a low-fat diet: type of fat and other nutrients are important, rather than total fat intake.
- Lifestyle advice The “5S framework” summarises the importance of 24-hour physical behaviors, including Stepping, Sweating (moderate-to-vigorous activity), Strengthening, Sitting (broken up by movement), and Sleep. The figure facilitates brief discussions on positive health behaviors and can be supplemented by our At-a-glance lifestyle factsheets.
Why is NAFLD a special concern in those with diabetes?
Liver disease affects up to 70% of people with type 2 diabetes. Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH), is the most common form of liver disease in people with diabetes. NAFLD can lead to cirrhosis and liver cancer and is associated with an increased risk of cardiovascular disease and death.
With one forth of the UK adult population believed to have NAFLD, and diabetes a risk factor for worse outcomes, it deserves special mention.
- The ADA reminds us that normal liver function tests (LFTs) do not rule out NAFLD. Those with persistently elevated LFTs should be investigated, and fatty liver on ultrasound or abnormal LFTs should prompt non-invasive fibrosis assessment using FIB-4 or NAFLD fibrosis scores, with further investigation or referral for intermediate fibrosis risk and referral for high-risk scores.
- For those at low fibrosis risk, 5–10% weight loss and CVD risk reduction strategies (smoking cessation, lipid, and blood pressure control) are recommended in primary care, with reassessment of fibrosis risk every 3 years.
- Those with type 2 diabetes should be treated with SGLT2 inhibitors or GLP-1 receptor agonists, which facilitate weight loss and reduce CVD risk.
This update emphasizes the importance of early detection of NAFLD in people with diabetes as well as appropriate management modalities. Early detection allows for timely treatment, reducing the chance of developing other serious complications.
Ref:
The 2023 ADA Standards of Care: What’s new?
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