Obesity and Liver Disease

During the recent Cleveland Clinic review course I attended, and again in a well recognized medical journal, concern is growing with the known increased risk of developing liver disease as one's weight increases. The disease is referred to as NAFLD - Non Alcoholic Liver Disease, or when it gets worse it is referred to as NASH or Non Alcoholic Steatohepatitis, where the liver may go on to cirrhosis.

What we know is that obesity is currently a worldwide epidemic and will likely only increase in prevalence in the years to come. The incidence of what is known as ‘Metabolic Syndrome' is increasing in conjunction with the obesity epidemic. Metabolic syndrome is a syndrome associated with increased visceral fat, high blood pressure, low HDL, high triglycerides and high blood sugar. Researchers feel that fat deposits in the liver are a manifestation of obesity and of Metabolic Syndrome. Insulin resistance appears to be the common factor.

NAFLD is defined as fat accumulation in the liver exceeding 5 to 10 per cent. The prevalence is higher than previously thought and we are noticing a greater prevalence in the younger population. In obese patients the prevalence has been reported to be in excess of 75 per cent. The prevalence of NASH (the more severe progression of NAFLD to actual inflammation of the liver) in the western hemisphere's general population is felt to be about 3 percent, although its prevalence in the obese population is about 20 per cent.

Adults typically present with this disorder between 40 and 60 years of age, whereas children are diagnosed around 12 years of age. Most people with NAFLD do not display symptoms and are discovered ‘accidently', when blood tests show abnormal liver function. Diagnosis is primarily made with liver biopsy, although there is a good chance that it can be confirmed with a combination of abnormal liver tests and evidence of fat deposits shown on ultrasound or CT scanning.

Currently, I would feel that lifestyle management is the best way to ‘manage' this disease. This would involve weight (especially abdominal weight) loss, and exercise. We aren't sure if exercise without weight loss can decrease the fatty deposits, so I would advocate both a calorie reduced way of eating and regular exercise, to decrease the fatty liver deposits and decrease the risk of these deposits causing cirrhosis and possibly primary liver cancer.

A current concern is that ‘in the absence of a safe and effective therapy for NASH, and the continued increase in the prevalence of obesity (and hence NASH), it is predicted that NASH will surpass hepatitis C as the most common indication for liver transplantation in the United States in the next 10 to 20 years.