Is NASH Caused by Obesity? 

By: Dr. Christopher McGowan

As obesity continues to rise in the United States, more and more obesity-related conditions are similarly becoming more prevalent. Overwhelming evidence from recent decades—in the form of randomized controlled clinical trials and various meta-analyses—has shown clearly that obesity can harm virtually any aspect of health. Yet while cardiovascular disease and conditions like type 2 diabetes mellitus are often the most well-known risks of obesity, an area of health that often goes overlooked is liver health. An example of a liver health issue that is seemingly connected to obesity has previously been known as non-alcoholic steatohepatitis (NASH). 

Dr. Christopher
DR. CHRISTOPHER MCGOWAN

Dr. Christopher McGowan, MD, a leader in endobariatrics, specializes in non-surgical obesity treatments and is triple-board-certified in Internal Medicine, Gastroenterology, and Obesity Medicine. Renowned for pioneering endoscopic sleeve gastroplasty (ESG) with over 2,000 procedures, his global influence and research contributions define him as a top expert.

Clarification on Terminology   

In just this past year, an international hepatology panel that included the American Association for the Study of Liver Diseases determined that the condition previously known as non-alcoholic fatty liver disease (NAFLD) will now be known as metabolic dysfunctionassociated fatty liver disease (MAFLD). Similarly, one of the two main types of MAFLD was previously known as non-alcoholic steatohepatitis (NASH) but is now known as metabolic dysfunction–associated steatohepatitis (MASH). This change was made in order to further highlight the close association between metabolic disorders and fatty liver problems as well as to open up new areas of research.    

What is MAFLD?

The newly-termed MAFLD is a set of medical conditions that are characterized by an accumulation of excess fat in the liver. As the old name implies, MAFLD is distinct from the kind of fat buildup in the liver that can come from excessive alcohol consumption. In this case, MAFLD can occur without a specific cause or with any cause other than alcohol consumption. The disease comes in two main types, and the milder of the two is called non-alcoholic fatty liver (NAFL) and involves fat accumulation but without significant inflammation or liver cell damage. 

The other main type is MASH (again, previously known as NASH), and it tends to be a more serious concern. MASH also involves fat buildup in the liver, but in this case inflammation can eventually lead to liver damage. Over time, this kind of liver damage can cause scarring (liver fibrosis) and cirrhosis, which is a type of permanent scarring that is associated with a loss of liver function. It is further believed that advanced fibrosis or cirrhosis can also lead to hepatic cancer (most commonly hepatocellular carcinoma).     

What Causes MASH? 

Unlike alcoholic liver disease, it is still unclear what causes the buildup of excess fat in the liver in MASH and NAFL. The reason the name was changed, however, is that recent research suggests metabolic syndrome (or dysfunction more broadly) likely plays a substantial role in the development of the disease. Researchers also believe there are a number of risk factors that can increase the likelihood of accumulating fat cells in the liver: 

  • Obesity: Being overweight or obese is one of the most significant risk factors for developing MASH. Obesity generally occurs when energy intake (measured in calories) exceeds energy expenditure; excess calories get stored as adipose tissue. As stores of lipids increase all over the body, fat also accumulates in the liver as hepatocytes (liver fat cells); when the liver accumulates fat in this way, it is called hepatic steatosis.
  • Insulin resistance: Another risk factor that has a strong link to obesity is insulin resistance, a condition where the body’s cells do not respond effectively to the hormone that regulates blood sugar levels. Insulin resistance usually means higher overall insulin levels in the bloodstream, and that also can promote excess fat being stored in the liver. 
  • Metabolic syndrome: Metabolic syndrome is a cluster of conditions that includes obesity, hypertension, high blood sugar, high triglycerides, or low HDL cholesterol. In addition to increasing the chances of MASH, metabolic syndrome also increases the overall risk of cardiovascular disease and type 2 diabetes. 
  • Diet: Unsurprisingly, just as obesity can be a risk factor for MASH, so can having a diet that is high in sugar (glucose) and unhealthy fats. Beyond leading to a calorie surplus, such dietary patterns tend to also be low in fiber, a key component in regulating blood sugar and cholesterol levels. Even if a diet like this doesn’t lead to obvious abdominal obesity, it can still cause fat to build up in the liver as well as the accumulation of visceral fat in other areas.  
  • Genetics: As with many types of disease, sometimes genetics can play a role in the chances of development. In the case of MAFLD, there is now evidence that about two thirds of families with a history of type 2 diabetes also have at least one family member who also has MAFLD.  

What are the Symptoms of MASH?  

Metabolic dysfunction–associated steatohepatitis is sometimes referred to as a “silent” liver disease because noticeable symptoms are not common in the early stages. Indeed, a buildup of hepatocytes may grow for years before causing enough damage to affect liver function. As the disease progresses, however, there are a number of symptoms that may present: 

  • fatigue or weakness
  • discomfort or pain in the upper right side of the abdomen 
  • unexplained weight loss
  • back pain    

It’s important to note that these symptoms are non-specific and can be associated with a variety of other conditions. The severity and combination of symptoms can also vary greatly from person to person. If left untreated, the disease may progress and lead to a whole new set of symptoms that stem from actual liver damage. Such advanced symptoms may include jaundice, ascites (build up of abdominal fluid), bleeding, or others.  

Diagnosis and Treatment Options

Since the symptoms are usually late to appear in the development of the disease, they are generally not a major factor when diagnosing. While a physical examination and blood tests can give some insight into liver health, imaging tests like MRI (magnetic resonance imaging) or transient elastography are helpful for detecting signs of damage or abnormalities. In some cases, a liver biopsy may be recommended to confirm the diagnosis and assess the severity of liver fibrosis. This is a fairly invasive procedure, however, and it is typically reserved for cases where diagnosis or disease staging are unclear.

A confirmed diagnosis of MASH is a serious concern because it means that there may already be some liver damage. And since some liver damage is essentially irreversible, it’s important to begin treatment as soon as possible. Most treatment options focus on managing the disease and preventing the progression to an even more serious type of liver damage. Below are some common approaches to treatment: 

  • Weight loss: Weight loss is one of the most valuable ways to manage the symptoms of MASH. Even losing as little as 5-10% of body weight can lead to overall improvement in liver health.  
  • Lifestyle changes: Adopting a balanced diet that is low in saturated and trans fats, sugars, and processed foods is an essential lifestyle change that can make a difference. Regular physical activity can also improve insulin sensitivity and some of the other factors that make MASH more likely.  
  • Medication: There are currently no medications specifically designed to treat NASH, but some medications associated with diabetes care can be used in certain circumstances. 
  • Surgery: In cases where the disease has progressed too far and damage to the liver is too severe, bariatric surgery may be called for. Bariatric surgery is usually meant to help people lose weight, but it can also be used to reduce fat deposits in the liver. In some cases a liver transplant may be needed when no other options are available.  

Trust True You for Weight Loss   

MAFLD, MASH, and various other liver-related conditions generally all benefit from losing weight. If you’re like most Americans, though, losing weight is easier said than done. That’s why at True You Weight Loss, we offer a new approach to weight loss that is ideal for helping you keep the pounds off, even years later. If you’d like to learn more about our non-surgical weight loss solutions, please contact us today to request a consultation. Freedom is waiting.

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