Hepatic steatosis is medical terminology for fatty liver disease that indicates the presence of extra fat in the liver. Heavy consumption of alcohol leads to a build-up of fat inside your liver cells which is referred to as alcoholic fatty liver disease (AFLD) or steatosis.
While most people think that AFLD or fatty liver disease only afflicts those who drink heavily, the fact is you can get the fatty liver disease even if you don’t drink alcohol. That’s called non-alcoholic fatty liver disease (NAFLD). By Dr R.S. Ramakrishnan, consultant radiologist, Medall Diagnostics, Chennai highlights the various alcoholic and non-alcoholic liver ailments:
Alcoholic liver disease
ALD develops in more than 90 per cent of those who consume 4 to 5 standard alcoholic drinks per day over decades, or after binge drinking, which is consumption of 4 to 5 drinks in 2 hours or less. Steatosis is the earliest, most common change. However, with the cessation of alcohol drinking, the liver returns to normalcy. Once steatohepatitis has developed, the risk of development of cirrhosis and liver failure is increased.
ALD can be diagnosed after examining and going through the history of alcohol use, clinical and laboratory findings of elevated liver enzymes - aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). However, sometimes, imaging and liver biopsy are also needed to establish a diagnosis.
Management of ALD includes:
- Cessation/ abstinence from drinking is considered the most effective therapy, lifestyle modifications (e.g., behavioural interventions and dietary alterations)
- Corticosteroid treatment, in moderate to severe alcoholic hepatitis
- High protein intake, micronutrient supplementation.
- Liver Transplant for those with end-stage liver disease.
Non-alcoholic fatty liver disease (NAFLD)
NAFLD refers to a group of conditions where there is an accumulation of excess fat in the liver of those who drink little or no alcohol. Many people are of the opinion that fatty liver is just another common ailment that doesn’t need much attention. Unfortunately, this is not the case. Up to 25 per cent of those with fatty liver steatosis ends up having a progression to NASH (Non-alcoholic steatohepatitis), which can end up in irreversible liver damage (cirrhosis) and even cancer. In fact, around a quarter of all liver transplant patients are those who suffer from NASH.
The overall prevalence of NAFLD in Asian countries varies from 9-40 per cent. As the pathogenesis of the condition is closely linked to insulin resistance (IR), its prevalence parallels that of increasing rates of obesity and Type 2 diabetes worldwide. Two decades ago, only 10 per cent of all diabetes cases had fatty liver. Today, it has risen to at least 60 per cent and many of them are teetotallers.
NAFLD is emerging as a significant cause of liver disease in even physically lean Indians who may be metabolically obese. Epidemiological studies suggest the prevalence of NAFLD be around 9-32 per cent in the general Indian population. The real cause is unknown since NAFLD is hardly diagnosed and most patients with NAFLD, even those with diabetes, have normal liver aminotransferases and clinicians do not suspect the potential presence of NAFLD. NAFLD minus cirrhosis is an independent risk factor for hepatocellular carcinoma and is the number one risk factor for cardiovascular disease.
Signs and Symptoms
With ALD and NAFLD, there are usually no symptoms. Some people may have signs such as tiredness or pain in the upper right side of the belly. If the individual has NASH or is suffering from cirrhosis, he/she may have symptoms such as swollen belly, enlarged blood vessels underneath the skin, larger-than-normal breasts in men, red palms and jaundices
Quantification of liver fat is important for detecting liver fat
Because hepatic steatosis is a pathogenic, potentially reversible condition even in severe cases, there is an urgent need, to detect its presence and to assess its severity. Accurate and precise quantification of liver fat is required to guide treatment of NAFLD with evidence-based weight loss.
Methods of liver fat quantification:
- Liver biopsy: Invasive; may not be the true representative of the disease.
- US: Mainly qualitative, machine and operator dependent, difficult on obese patients, poor repeatability and reproducibility.
- CT: Issues of radiation.
- MRI: Non-invasive; no radiation; fast (2 minutes scan); clinically validated against biopsy measurements of liver fat and is more reliable/reproducible.
Management of NAFLD/NASH requires a multi-system, integrated approach and includes:
Weight reduction if obese or overweight, control of diabetes, increased physical activity, following a balanced diet rich in monounsaturated fatty acids, management of hyperlipidemia, and avoiding alcohol and unnecessary medications. In addition, patients are advised to undergo standard cancer screening examinations according to their age, gender and family history. With early detection, regular exercise, diet and with physician’s help liver diseases can be avoided.