Also called nonalcoholic fatty liver disease occurs when there is too much fat in the liver or steatosis.
The condition is also known as fatty liver.
There may be no symptoms early, but ongoing liver damage can worsen a more severe condition.
People with nonalcoholic fatty liver disease (NAFLD) develop nonalcoholic steatohepatitis (NASH). This can lead to cirrhosis or scarring and dysfunction of the liver.
Fatty liver is often linked to obesity, high blood pressure, diabetes, and high cholesterol. NAFLD or NASH is not due to increased alcohol consumption.
Fatty liver can also occur during pregnancy, and cirrhosis can result from alcohol-related liver disease, but NAFLD is considered a separate diagnosis and is handled differently by doctors.
Fast facts on fatty liver disease
Nonalcoholic fatty liver disease (NAFLD) can occur if too much fat builds up in the liver.
Many people have a fatty liver without symptoms, but it can progress to a more severe condition in some cases.
The exact cause is unknown, but obesity appears to be a risk factor.
Following a healthy, balanced diet low in sugar and trans fat can help prevent or even reverse the disease.
People with liver disease should avoid alcohol or consume only tiny amounts.
Symptoms and stages of hepatic steatosis
Fatty liver disease often occurs with obesity, diabetes, and chronic kidney disease.
The liver is essential for removing toxins from the body. If it does not work correctly, various symptoms can arise.
If the body produces too much fat, or if the fat is not metabolized correctly, it can accumulate in the liver.
If too much fat builds up in the liver, this can cause fatty liver. If the fat continues to accumulate, this can lead, in some cases, to NASH and eventually to cirrhosis and liver failure.
More than 5 to 10 percent of the liver’s weight is fat at a threshold level. If more fat accumulates in the liver, this is known as NAFLD or simple fatty liver.
It is not healthy but not necessarily severe enough to cause any problems, and the person will generally not notice any symptoms.
Most people with simple fatty liver will not know they have it. It may only be discovered after being tested for other conditions or because other risk factors suggest that a test is a good idea.
If the fat accumulates and the liver becomes inflamed, it results in NASH.
About 75 percent of patients will have liver swelling or hepatomegaly.
Symptoms can include:
- Tiredness and fatigue, including muscle weakness and lack of energy.
- Discomfort and possibly bloating in the upper abdomen.
- Poor appetite
Symptoms can be vague and can resemble several other problems. Tests can be carried out to eliminate other conditions.
Scientists are not sure why some people are more likely to develop NASH.
Cirrhosis and liver failure
Over time, 10 to 25 percent of people with NASH will develop scarring or fibrosis, also known as cirrhosis and liver failure.
- Tiredness and weakness
- Nausea, vomiting, and diarrhea.
- Tarry stools.
- Abdominal bloating and pain
- Yellowing of the skin and eyes is known as jaundice.
- Confusion, trouble focusing, memory loss, and hallucinations.
- Skin itch.
- Bleeding and bruising easily.
In severe cases, a liver transplant may be necessary.
Everything you need to know about cirrhosis
Cirrhosis can result if the fatty liver disease progresses to a more severe stage.
Causes and risk factors
Exactly how and why fatty liver develops is unclear. It occurs when the body produces too much fat or cannot process fat properly.
Obesity is an obvious risk factor. About 70 percent of people with obesity have the condition, while 10 to 15 percent of people of average weight have it.
Regardless of their weight, a person with “deep” abdominal fat is more likely to have a fatty liver.
Other risk factors include:
- High cholesterol or high levels of fat in the blood.
- High blood pressure.
- High levels of fats in the blood or triglycerides.
People with metabolic syndrome, which involves clustering the risk factors listed above, are at higher risk.
Between 40 and 80 percent of people with type 2 diabetes have NAFLD.
Researchers have found “growing evidence” that NAFLD is linked to cardiovascular disease (CVD) and chronic kidney disease (CKD).
This means that those with NAFLD are also more likely to have diabetes and heart disease.
While there are clear links between obesity and fatty liver, some people develop NAFLD without obesity. This suggests that there are other factors.
- Genetic influences.
- Advanced age.
- Certain medications, such as steroids and tamoxifen for the treatment of cancer.
- Rapid weight loss
- Infections, such as hepatitis.
- Exposure to some toxins.
However, research suggests that “excess fat mass is still the most common underlying condition.”
NAFLD is also the most common form of long-term liver disease in children. A review published in 2016 indicates that it affects between 10 and 20 percent of pediatric patients and between 50 and 80 percent of children with obesity.
Diagnosis of hepatic steatosis
The initial stage of NAFLD usually does not produce symptoms, so the diagnosis usually occurs due to a routine blood test or the person has the relevant risk factors.
If the doctor suspects NAFLD, they will feel the abdominal area to determine if there is swelling. They will ask about diet, lifestyle, medications, supplements, and alcohol.
If tests suggest liver damage or that the liver is inflamed, the doctor must rule out other possible conditions, including alcoholic liver disease.
Imaging scans, such as ultrasound, CT, and MRI, can show fat in the liver.
A biopsy can confirm NAFLD, reveal the extent of the damage, and distinguish it from other types of liver problems. The doctor will use a needle to remove a small tissue sample from the liver.
Multiple treatments have been investigated for the control of hepatic steatosis. However, few have scientifically proven results. Let us summarize the main steps that can be taken to treat steatosis.
The most effective measure to control hepatic steatosis is weight loss. Studies show that a reduction of just 7% in body weight can provide excellent results.
Therefore, an obese or overweight person who weighs around 80 kilos would need to lose about 5 kilos to present regression of liver fat accumulation.
We suggest physical activity and consumption control in order of calories that the patient loses between 0.5 and 1 kg per week. Very rapid weight loss caused by rigorous diets can have the opposite effect, aggravating steatosis.
You do not need to rush. A slow but ultimately weight loss is the best way to fight steatosis.
Weight loss, of course, works only for obese or overweight people. People with body mass index (BMI), between 20 and 25 kg / m 2, did not have a significant benefit since the cause of their steatosis is not excessive body fat.
The suspension of alcohol consumption is essential to prevent steatosis from evolving into steatohepatitis and liver cirrhosis.
People with signs of liver fat accumulation should avoid alcohol altogether.
Small amounts of alcohol ingested sporadically probably should not cause harm, but the minimum safe dose in these cases is unknown.
As many patients with steatosis caused by alcohol are used to drinking large amounts of alcohol, it is best to educate them to avoid drinking altogether.
Patients with NAFLD are at increased risk for cardiovascular disease, so controlling risk factors is essential to lower the risk of heart complications.
Weight loss, physical activity, control of blood pressure levels, smoking cessation, and statins (drugs to control cholesterol) should be instituted when necessary.
The use of drugs to control cholesterol does not act directly on steatosis, but it does help reduce cardiovascular risk in these patients. If the patient has high cholesterol, the presence of steatosis is another reason for its control with medications.
Vaccination for hepatitis A and B
Patients with steatosis and especially steatohepatitis had unfavorable results if they were infected with any of the forms of viral hepatitis. Therefore, vaccination against hepatitis A and hepatitis B is indicated for those not immunized.
Vaccination does not affect steatosis; it only serves as protection against other liver problems.
There is still no vaccine for hepatitis C.
Stop harmful drugs
Suppose the patient begins to accumulate fat in the liver as a side effect of medications such as corticosteroids, estrogen, tamoxifen, amiodarone, etc. In that case, the treatment should, whenever possible, aim at the discontinuation of these medications.
Drugs for hepatic steatosis
Unfortunately, the measures that have been shown to benefit fatty liver patients are only described in the previous section.
Dozens of drugs have been studied to treat steatosis. However, none of them so far have managed to gather substantial scientific evidence so that we can affirm their efficacy and specifically indicate them for treatment.
We will summarize the results of the most studied drugs for steatosis and steatohepatitis.
Studies of vitamin E have shown conflicting results. There is a consensus that vitamin E has no advantage for simple steatosis.
However, patients with liver biopsy-proven signs of steatohepatitis and liver fibrosis appear to benefit from treatment with 400 to 800 IU of vitamin E per day.
Hypoglycemic drugs such as metformin, pioglitazone, and rosiglitazone, the commonly used treatment for type 2 diabetes, have been studied as an alternative for steatosis.
However, no studies have shown the effectiveness of these drugs in patients with steatosis without changes in blood glucose.
Therefore, these drugs should not be used to treat steatosis unless the patient has diabetes and has an indication for treatment with oral hypoglycemic agents.
Studies have shown that the beneficial effect of orlistat is directly related to the patient’s weight loss. The drug does not act now on steatosis.
Therefore, orlistat can be used to treat steatosis alone as an adjunct drug to control body weight.
Some studies have shown omega-three benefits in steatosis, but not steatohepatitis.
Patients with high triglycerides also seem to benefit. However, more conclusive studies are needed before omega three can be indicated as an effective treatment for hepatic steatosis.
Various other medications have been tested in multiple studies, but always with mixed results. Among them, we can mention:
- Ursodeoxycholic acid.
- Folic acid.