Facts About Obesity And Fatty Liver
One of the main causes of fatty liver disease is related to alcohol consumption. The other category is of non-alcoholic fatty liver disease (NAFLD) which is likely to be the most common cause of chronic liver disease worldwide. The syndrome of fatty liver encompasses a broad category of changes in the liver, secondary to tat deposition.
Estimated numbers affected by NAFLD amounts to almost a quarter of the population with some studies showing a prevalence of up to 30-46 per cent of the general population being affected. In India, the occurrence has been estimated between 9-30 per cent. Over the years, our changing lifestyles reflect what we eat and what we do and the increased numbers of the obese population have contributed to a significant increase in the incidence of this seemingly benign condition.
Major Risk Factors
The major risk factors for the development of fatty liver disease includes alcohol, obesity, metabolic syndrome with elevated triglyceride levels and insulin resistance, type 2 diabetes mellitus (about 35-80 per cent of Indian diabetics are said to have NAFLD), associated atherosclerosis, including cardiovasculardisease and hypothyroidism.
Although the prevalence of NAFLD increases with age, what is alarming is that cases are being diagnosed even in the early twenties with few studies documenting fatty liver even in childhood obesity.
The BMI Classification
Indians have seen a changing trend from being lean to overweight/obese. The international classification for overweight defines a BMI (Body mass Index) of 25 kg! metre square and obesity as more than or equal to 30 kg / metre square. The accepted classification for the Asia Pacific region is much lower with overweight being classified as BMI of more than 23 kg/metre square and obesity more than 25 kg/metre square. With these revised numbers, more of our population falls In these categories.
Even at a lower BMI, we have more of visceral fat with central or abdominal obesity (classic apple shape) and a higher percentage of total body fat than the worldwide population which translates to a higher risk of NAFLD.
The spectrum of NAFLD ranges from simple tat accumulation in the liver (called steatosis) to steatohepatitis – non alcoholic steatohepatitis also called NASH in which inflammatory changes develop in the liver. The progression to NASH is worrying as patients with NASH are at a higher risk of developing cirrhosis and even hepatocellular carcinoma (liver cell cancer).
Symptoms And Diagnosis
Most patients with fatty liver do not report any symptoms. However, some may have mild dyspepsia and occasional pain over the right upper abdomen due to liver enlargement. Most often, an ultrasound examination of the abdomen done for some other reason incidentally detects fatty liver and associated changes which are radiologically graded (Grade I to 3). Further evaluation such as CT or MRI is rarely necessary and contemplated if NASH and its progression is to be determined.
A simple liver function test (LFT) may determine functionally, how much the liver is affected (although liver enzymes may be elevated due to other reasons too). Usually the GGT is seen to be A simple liver function test (LFT) may determine functionally, how much the liver is affected (although liver enzymes may be elevated due to other reasons too). Usually the GGT is seen to be high, later the transaminases (SGOT, SGPT) also are elevated. Blood sugar estimation to screen for diabetes mellitus, a lipid profile and if necessary a thyroid profile, helps pick up some of the treatable causes of fatty liver.
Fibroscan (transient elastography) is a technique which assesses the liver fibrosis (liver stiffness) quantitatively with a scoring system. The progression from simple steatosis to NASH may be predicted by a set of criteria. Liver biopsies are sometimes recommended for further diagnosis of worsening to cirrhosis or malignancy.
The best way to tackle the problem of a fatty liver is through lifestyle modifications. Irrespective of being overweight or obese, all patients with fatty liver are encouraged to exercise regularly. Physical activity helps to reduces insulin resistance, even without the additional benefit of weight loss.
A good aerobic activity (brisk walking, jogging or any other form of aerobic exercise) for at least 45 minutes daily for at least five days a week is recommended. Overweight/obese people are encouraged to lose at least five-ten per cent of their baseline weight by about six months.
Overall, dietary calorie restriction, including low fat, low carbohydrate diets is beneficial. A careful watch on trans fat and hidden fat consumption is essential, Also, abstinence from alcohol and avoiding use of hepatotoxic drugs limits further liver damage.
The drugs studied for the treatment of fatty liver include vitamin E supplements, ursodeoxycholic acid, omega 3 fatty acids, pioglitazone and newer drugs like obeticholic acid have shown only minor benefits.
Early initiation of lifestyle changes with a focus on a healthy diet and regular physical activity, starting at a young age and regular follow-up once fatty liver is detected, are simple measures which will go a long way in dealing with this condition and preventing its complications.