Fatty Liver Fatty LiverDiagnosisTreatment Yellow appearance of a liver with excess fatWhat is fatty liver? Answer : simply what the name suggests - too much fat in the liver! Some important facts: Fatty liver is the accumulation of fat (mainly as triglycerides) within liver cells. This happens when the fat coming into the liver is more than the fat going out (the liver makes and secretes fat). This condition is becoming more common. It is the commonest cause of abnormal liver enzyme tests (blood tests for the liver). This is because fat in the liver may cause some inflammation. What causes fatty liver? Excess alcohol intake may be the main underlying cause. How much is too much? Refer also to section on alcohol and liver. One study showed that the risk of moderate alcohol intake (2 standard drinks per day; less than 20g) causing NAFLD is 5-fold for non-obese men, 15-fold for overweight men and 35-fold for obese men. Safe limit may only be 3 standard drinks per week - better to be nil There are an increasing number of people with fatty liver that is NOT caused by alcohol. This condition has an association with being overweight, having diabetes (or pre-diabetes - also called impaired glucose tolerance - and having raised cholesterol or raised triglyceride levels in the blood. The underlying problem is considered to be "insulin resistance". This means that the body is not responding normally to the insulin hormone. This problem directly relates to the amount of fat tissue in the body. Fatty tissue is not inert. It secretes a range of hormones that control the body's metabolism. Insulin resistance promotes increased rate of delivery of fat to the liver from the tissues. Insulin resistance (and therefore fatty liver) is primarily determined by body weight and also the level of physical activity. Fatty liver is a marker for significant insulin resistance and is associated with a 2- to 5-fold risk of developing type 2 diabetes The main risk to health with fatty liver is not severe liver disease but diabetes, heart disease and stroke - all long term consequences of insulin resistance / metabolic syndrome Fatty liver is more common some ethnic groups. That is, for a given weight there is more fatty liver in some groups. It is more common with Indian and Chinese compared with European groups. It is also more common in Pacific Islanders. About 10% of people with excess fat in the liver will develop inflammatory in the liver. The medical term is called steatohepatitis. This sometimes abbreviated as NASH - non-alcohol steatohepatitis. Another abbreviation is NAFLD (non-alcoholic fatty liver disease). This inflammatory process, if sustained over a long period of time, can lead to significant liver fibrosis and eventually to cirrhosis (severe liver damage). The risk is low (compared to other causes of liver disease). Overall only 2% will progress to cirrhosis. This is a much smaller risk than for fatty liver caused by alcohol Abdominal fat is the main risk factor for fatty liver. The important test is the waist meaurement!! This should be less than 100cms for men.How is the diagnosis made? There are two main ways in which the diagnosis can come to light! As a result of investigation of abnormal liver tests. OR incidental finding at ultrasound performed for other reasons (e.g investigation of right–sided abdominal discomfort). Fatty liver is thought to cause no symptoms but fatigue and ill-defined discomfort in the right upper abdomen may be present (probably not a direct effect of the condition). The liver is usually of normal size. Fatty liver should be suspected if there are risk factors. They are : Being overweight (BMI more than 30 - weight in kgs divided by height in metres2(squared). High blood lipids or fats (raised blood cholesterol and/or trigylcerides). Diabetes mellitus (or raised blood glucose but not quite diabetes - called impaired glucose tolerance). Other features of the metabolic syndrome are hypertension and increased waist circumference (100cms for men; 90cms for women). There is an association with polycystic ovary syndrome – this condition is also considered to be due to insulin resistance. Excess alcohol intake. Even 5-10 "standard" drinks per week may be significant if combined with other risk factors. Fatty liver can occur without any risk factors. Ultrasound is reasonably sensitive for detecting fatty liver. This picks up 2/3 rds of cases - liver is echogenic or bright on ultrasound. Ultrasound is a useful screening test. Fatty liver may be the cause of abnormal liver tests even if the ultrasound is normal. Occasionally CT scan is required. It is common to have a raised serum ferritin with fatty liver. This can cause confusion as ferritin is also elevated with haemochromatosis, a condition where there is an overload of iron in the body. Further testing The most useful way of assessing the severity of fatty is by Fibroscan This can assess the degree of fibrosis in the liver. This is the main consideration for long term outcome and the risk of progressing to cirrhosis. The test may not pick up mild fibrosis and can be limited in accuracy by obesity Liver biopsy is rarely required Predictive models and scoring systems may be useful. Calculators for risk can found online. The online NAFLD calculator involves a simple formula using serum albumin, AST/ALT ratio platelet count, age and the presence or absence of impaired glucose tolerance (prediabetes) or diabetes. Ask your doctor to check this; not yet widely used but likely to become standard practice. The risk of progression to cirrhosis is higher if the fatty liver is caused by alcohol. Particularly if alcohol intake is continued (at the same level of consumption). Treatment The treatment is weight loss. Weight loss by liposuction or surgical removal of abdominal fat (apronectomy) does not work!!! There is no shortcut - reduction in calorie intake is the only way. Risk factors should be reduced. Diabetes tablet treatment may need to be started or increased. There may be a role for newer treatments for type 2 diabetes such as liraglutide (not yet funded in NZ) Medication for raised cholesterol (statins) and trigycerides (Bezalip) may need to be started. There are no studies to support a direct benefit of statins drugs in fatty liver however lipid lowering is important for reducing cardiovascular risk. Fatty liver does not lead to a higher risk for liver injury from statins. Alcohol intake must be reduced. It is better to stop completely. A possible safe limit is 2-3 standard drinks per week. There is an interatction between obesity and alcohol intake. i.e the higher the weight (BMI) the more the risk with even modest alcohol intake Exercise is crucial to success. Exercise has an important role in the treatment of fatty liver because it reduces insulin resistance – which is the underlying problem. i.e the effect of exercise is not just mediated through weight loss. This needs to be daily activity with a plan for gradual increase in activity levels. Exercise needs to be aerobic. This means "huffing and puffing" for more 30 mins three times a week!! Weight training will not be helpful (not harmful either). Weight loss should be gradual. About ½ kg per 1-2 weeks is ideal. Rapid weight loss can aggravate fatty liver. Slower rates of weight loss are more likely to be the result of lifestyle changes that can be maintained for the long term. There is no quick fix! A gradual and sustainable change in lifestyle is the goal. Modest weight loss (less than 5%) can have a significant effect if combined with regular exercise but a 5-10% weight loss should be the goal. The traditional advice has been that there is no special diet. This is no evidence to support specific claims of the "liver cleansing diet". A reduction in fat intake and reduction in alcohol intake are going to be essential changes to achieve enough calorie reduction to lead to weight loss. Recent evidence supports a low carbohydrate diet. In particular, it appears that excess fructose causes fatty liver. Fructose is used in a lot of commercially prepared foods especially soft drinks. Low carbohydrate diets are the most effective way to lose weight. There is interest in the role of probiotics - it appears that gut bacteria have a role in mediating body metabolism - this is an emerging area. Realistic goal setting and regular follow-up with your doctor helps. Weight loss using a very low calorie diet is typically greater than the 10% but maintenance of weight loss is challenging in the long term. A low carbohydrate diet may improve fatty liver more than other forms of dietary restriction however the evidence is mixed. The magnitude of the improvement following exercise interventions appears to be less than in dietary interventions. Combination interventions appear to be the most effective. The most intensive intervention trials report the highest losses in body weight and a greater improvement in NAFLD. The Mediterranean diet (higher in monounsaturated fatty acids) has also been studied in comparison to a high-fat, low-carbohydrate diet for 6 weeks. There was no change in weight loss but MRI results showed significant improvement in steatosis in the Mediterranean diet group. Weight – reduction surgery could be considered in severe cases. Gastric banding or gastric bypass has some proven efficacy for severe cases. The weight loss after gastric banding is less (maybe 15-20%) and there have been some long term concerns particularly erosion of the band into the stomach. Weight loss after gastric bypass may be 40-50% of initial weight. However this comes at a price. There are post-operative problems and a risk of death (approx 1%). There may be abdominal pain after meals. Nutrient deficiencies can be a problem after several years. Other medications. Metformin reduces insulin resistance and may be helpful but still limited information. Antioxidants such as vitamin E may have a role, perhaps for more sever disease. Trials shown show some reduction in fatty liver but safety data is debated. There was actually an increase in overall mortality. Medications for diabetes and cholesterol (as discussed above).