Obesity and Non-Alcoholic Fatty Liver Disease

Some obesity-related diseases, such as diabetes and hypertension, are well known, not only in the medical community but also to the greater public. However, other health conditions with equally severe consequences are less frequently discussed, and unfortunately those at high risk may be unaware of the potential impact. Hepatic disease and cancer linked to obesity are examples of such consequences.

Among all types of liver disease, Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common and also the type most likely to require liver transplantation. And though specific causes remain unclear, research suggests that of Non-Alcoholic Steatohepatitis (NASH) and NAFLD contribute to the development of Hepatocellular Carcinomas (HCC), the second leading cause of cancer mortality worldwide. There also are links between the gut-liver axis and obesity-associated liver cancer, as well as NAFLD and risk of cardiac dysfunction.

When the liver becomes fatty, inflammation and insulin resistance occur. At the same time, insulin resistance can contribute to developing a fatty liver because it increases free fatty acid delivery. Insulin resistance forces the pancreas to produce more insulin, which can be a precursor to type 2 diabetes. Other comorbidities associated with a diseased liver include hypertension and high cholesterol. Although fatty liver disease is more typically associated with alcoholism, NASH affects between 70 and 90 percent of people with obesity and diabetes.

NAFLD has no symptoms so patients are unlikely to know they may be affected unless a blood test indicates elevated ALT and/or AST. There are conflicting views on whether new screening strategies for NASH would be beneficial. Those in favor suggest that identifying biomarkers and enhanced screening would improve management of the disease among patients with severe obesity. Conversely, those who critique this approach point to a study in which new European guidelines were retrospectively applied to 313 cases, which would have led to up to 289 patients being referred to a specialist. This was viewed as excessive and as unnecessarily contributing to health costs.

Some pharmacological interventions show potential for treating NAFLD, and animal studies  indicate that a combination of  docosahexaenoic acid (DHA) and the antioxidant hydroxytyrosol (HT) can prevents development of liver steatosis and mitochondrial dysfunction brought about by high fat diets. However, weight loss is a better long-term solution as it addresses NAFLD as well as many of the comorbidities linked to patients with obesity.

Using a Very Low Calorie Diet (VLCD) as part of a long-term weight loss program can contribute to a level of weight loss that can help resolve or even reverse certain medical conditions. Some studies have found that a VLCD, used under close medical supervision, can be well-tolerated and offer a safe weight loss alternative for patients awaiting liver transplantation. It is important that both the medical community and patients be informed on the full range of options available to treat their specific circumstances to limit risk or best address their medical conditions.