Of fat livers and such
FATTY liver (FL) has for a long time been associated with heavy alcohol consumption and was thought to be a prelude to cirrhosis or hardening of the liver.
Non-alcoholic fatty liver disease (NAFLD), however, is a fairly recent "disease". It was first described in the medical literature in 1980 by a Dr. Ludwig from the Mayo Clinic, US.
Following its initial description, NAFLD has been increasingly diagnosed. This is due to the increased awareness of the condition amongst doctors and patients and the widespread use of ultrasonography in health screening of patients.
We are also seeing a true increase in prevalence of the disease with the growing affluence of the population throughout the world and its associated changes in diet and other lifestyle changes.
Basically, FL refers to the deposition of fat in the cells of the liver. When this happens, it usually affects every cell in the liver. Strictly, the diagnosis is made on microscopic examination of a liver biopsy. However, when the deposition is significant enough, this can be detected by scans of the liver.
Ultrasonography is the most widely used scan, and uses sound waves to study organs of the body. It is a safe and non-invasive method. When there is fat in the liver, there is increased reflection of sound waves, which is detected by increased "brightness" on the scan.
It is the easiest way to detect FL and is generally a very reliable diagnostic tool, although it has some limitations, mainly under-diagnosis when the amount of fat in the liver is not substantial enough.
Newer ultrasonography machines are more sensitive and can give a very accurate assessment of the amount of fat in the liver. Ultrasonography, is in fact, employed as a diagnostic tool for FL in many scientific studies looking at the prevalence of FL in a particular population.
While many patients are detected to have FL based on screening ultrasonography, many more patients are detected to have liver function test abnormalities on blood testing and are then referred for ultrasonography when the diagnosis of FL is then made.
FL is part of a spectrum of diseases that is frequently referred to as the "metabolic syndrome". It is associated with diabetes mellitus, hypercholesterolemia, hypertension and coronary artery disease. FL reflects the abnormal metabolism or handling of sugar and fat in the body by the deposition of fat in the liver (and which also occurs in other organs including the heart and the brain).
Patients with FL are usually overweight and lead a relatively sedentary lifestyle. It is most commonly seen in affluent countries, not just in the West, but in the Asian-Pacific region as well and points to the contributory role of an unhealthy diet, increasing obesity and lack of exercise in the population – all part and parcel of modern living.
Genetic factors also play an important role, and also underlie FL associated diseases such as diabetes and the "hyperlipidemia syndromes". Family history is therefore an important indicator as to who may get FL.
An ultrasonograph-based survey of patients who came for health screening in an urban medical centre in Malaysia shows a prevalence of FL of up to 20%. This figure appears to be the same for all the three major races in the country: Malay, Chinese and Indian. Men have a higher prevalence compared to women. A strong association of FL with diabetes and high cholesterol levels have been noted.
How does FL affect the patient's health in the long term? FL is generally regarded as a relatively harmless liver disease. This is probably true based on current scientific knowledge but there are studies that have shown the evolution of FL to cirrhosis and even liver cancer in a small proportion of patients.
The greater implication of FL is the almost inevitable association with other "metabolic diseases" and it may well be that associated diseases such as coronary artery disease may be more frequent and significant in these patients than the liver disease itself.
There is no medication per se that can treat FL directly. Diabetic drugs like metformin has been shown to be useful in the treatment of patients with diabetes and FL.
Preliminary evidence shows that a group of drugs called the thiazolidinediones, which improve insulin sensitivity in the body and are used for the treatment of diabetes mellitus, appear promising in the treatment of fatty liver. More studies need to be done before these drugs can be approved for use for the treatment of fatty liver.
Patients with concomitant diabetes and hyperlipidemias should be treated appropriately. The concern of many doctors is the use of statins which themselves can cause a rise in liver enzymes in patients with FL. The consensus opinion of experts is to use statins when needed as the risk of liver dysfunction is thought to be insignificant and the benefits of the drugs are more important to the patient.
Physical activity and weight loss has been recommended to patients. It is likely to be good for the FL and in any case helps with overall health of patients with FL.
A group of agents called essential phospholipids or phosphotidylcholine, have been used in the treatment of alcoholic fatty liver disease. Phospholipids form the membrane of every cell in the body and it is thought that the integrity of this membrane is vital to the health of the cell and the organ system and with particular reference to the liver.
It is thought that oral supplements of these compounds will help in the health of the liver.
Several studies, albeit small ones, have shown its usefulness in alcoholic liver disease and alcoholic fatty liver and it may have a beneficial value in non-alcoholic fatty liver disease as well.
Another compound is betaine glucuronate combined with diethanolamine glucuronate and nicotinamide ascorbate, which has also been used locally for liver disease. Scientific data for its use and benefit in fatty liver is sparse. Several other agents have been sold "over the counter" as "liver tonics". Most have unproven value in fatty liver or any liver disease at all.