Sunday November 15, 2009
Another fat problem
Eight out of every 10 obese individuals usually have fatty liver disease.
AN often heard phrase, “obesity, the gateway to diseases”, holds many truths. Obese people have a higher risk of developing cardiovascular diseases, hypertension or high blood pressure, diabetes, arthritis, and certain cancers, to name just a few.
Approximately 300,000 deaths per year in the United States can be attributed to obesity. A US report revealed that obesity-related deaths in the US rose by 33% from 1994 to 2004 and it is expected to overtake tobacco as a leading preventable cause of death in the near future.
In Malaysia, 29% of the adult population has been found to be overweight, while 14% are obese. This means that if we randomly pick 100 individuals from the street, 14 of them will be obese. This figure could easily be 17 out of 100, depending on how we measure obesity.
How many Malaysians fall into this category? A mind-numbing 4.6 million!
Obesity is defined as an excess amount of body fat. One easy way to define obesity is by calculating the body mass index (BMI). BMI is a mathematical formula which calculates the degree of obesity based on a person’s weight and height. Let’s take a look at an example:
Kelvin is 1.75 meters tall and weighs 100 kg. His BMI is:
BMI = weight (kg) / [height (m) x height (m)] = 100/(1.75 x 1.75) = 33 kg/m2.
So now, what does 33 kg/m2 mean? The World Health Organization (WHO) classification differs slightly from Malaysia’s, as the latter adjusts for the physical build of the Asian population.
BMI (Source: World Health Organization) – normal weight = 20.0 – 24.9; overweight = 25.0 – 29.9; obese = ≥ 30.0
BMI (Source: Clinical Practice Guidelines on Management of Obesity, 2004, Malaysia) – normal weight = 18.5 – 22.9; overweight = ≥ 23.0; obese = ≥ 27.5.
Another popular method of defining obesity is by measuring waist circumference. Waist circumference has been established as an important indicator of abdominal obesity.
Men with a waistline circumference of more than 40 inches and women greater than 35 inches are at a higher risk of developing obesity-related diseases. One such disease is fatty liver, which affects eight out of every 10 obese individuals.
Fatty liver
Obesity-related fatty liver is categorised under non-alcoholic fatty liver disease (NAFLD), which simply means that the fatty liver is not caused by alcohol. NAFLD refers to a wide spectrum of liver diseases which include common fatty liver, non-alcoholic steatohepatitis (NASH), and cirrhosis.
Accumulation of fat in the liver is common in all stages of NAFLD. A portion of NAFLD patients will develop a more serious condition known as non-alcoholic steatohepatitis (NASH), where the accumulation of fat in the liver causes liver inflammation. If left untreated, the condition will worsen to cirrhosis, which is characterised by irreversible, advanced scarring of the liver due to chronic inflammation.
A study conducted at University Malaya Medical Centre (UMMC) revealed that consistent with other published literature, 80% of the study participants who had fatty liver were either obese or overweight. In another study looking at the prevalence of non-alcoholic fatty liver disease in obese populations within the Asia-Pacific region, the following statistics were obtained.
● Japan – 50 – 80 % obese individuals had NAFLD
● China – 70 – 80 % obese individuals had NAFLD
● Korea – 10 – 50 % obese individuals had NAFLD
● India – 15 – 20 % obese individuals had NAFLD
● Indonesia – 47 % obese individuals had NAFLD [Source: Amarapurkar D.N. (2007)]
The likelihood of having NAFLD is directly proportional to body weight. The body mass index (BMI), which was discussed earlier, correlates with the degree of liver damage – the greater the BMI, the greater the liver damage.
If you are someone who falls into the category of being obese and having a fatty liver, there are several potential approaches to manage the condition. They include:
● Treating the risk factor, which in this case is obesity (weight reduction via diet and exercise)
● Pharmacological treatment of insulin resistance
● Use of lipid-lowering agents
● Use of liver protecting agents e.g. essential phospholipids
Non-alcoholic fatty liver disease that is due to obesity can be largely prevented by promoting good eating habits and active lifestyles.
This, however, can sometimes be challenging for a society which has gotten so used to living a sedentary lifestyle and consuming food high in calorie, carbohydrate and fat.
It is important for obese individuals to understand that they are predisposed to many medical conditions (including fatty liver) and it is time for them to take the necessary corrective measures seriously.
References:
1. Sleisenger and Fordtran’s Gastrointestina and Liver Disease 8th Ed 2006.
2. Amarapurkar et al. Journal of Gastroenterology and Hepatology. 2007.
3. Dennis Lee and Jay W. Marks. Body fat, the silent killer – article in MedicineNet.com. Available at http://www.medicinenet.com/script/main/art.asp?articlekey=46582. Accessed June 2009.
4. William D Balistreri. Fatty Liver Disease – a major cause of obesity-related morbidity and mortality – article in Medscape. Available at http://cme.medscape.com/viewarticle/506625. Accessed June 2009.
5. Ministry of Health. Nutritional Status. The Third National Health and Morbidity Survey 2006. Malaysia.
n This article is courtesy of sanofi-aventis. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
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