Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is a medical condition in which there is an abnormally high buildup of fat in the liver. It affects about a quarter of Canadians. These numbers are rising as are the associated risks of liver failure, liver cancer and death.
Causes
MASLD occurs due to metabolic and/or cardiovascular abnormalities, such as obesity, diabetes, high blood pressure and high cholesterol. These ‘cardiometabolic’ risks arise from a combination of genetic, lifestyle, environmental, hormonal, and gut microbiome-related factors.
High buildup of fat in the liver can progress to inflammation (metabolic dysfunction-associated steatohepatitis (MASH)) and scarring (fibrosis). In its most advanced stage, when fibrosis is so extensive that it prevents the liver from functioning appropriately, it is termed cirrhosis. Cirrhosis typically is irreversible and associated with high risk of complications, hospitalization and death.
Symptoms
Most individuals with MASLD do not have any symptoms. Some may experience tiredness, a generalized feeling of being unwell, or vague discomfort in the upper right abdomen.
Potential complications
One-fifth (20 per cent) of patients with MASLD can develop significant inflammation in the liver, termed metabolic dysfunction-associated steatohepatitis (MASH). This inflammation causes injury and scarring of the liver. Over time, one-fifth of patients with MASH develop cirrhosis, altering its ability to function.
Cirrhosis can lead to complications such as fluid buildup in the abdomen (called ascites), confusion (termed hepatic encephalopathy), life-threatening bleeding from high pressure veins in the esophagus (known as variceal bleeding), and liver cancer or hepatocellular carcinoma. In some patients with MASLD, liver cancer can arise even before cirrhosis develops.
MASLD has also been associated with a higher risk of developing non-liver cancers, such as uterine, stomach, pancreas, and colon cancers.
Individuals with MASLD are at higher risk of developing heart attacks, heart failure, abnormal heart rhythms and strokes, due to the association with obesity, diabetes, high blood pressure, and high cholesterol.
Who is at risk for developing MASLD?
Individuals with metabolic abnormalities such as obesity or overweight status, diabetes, high blood pressure and high cholesterol, are at risk for developing MASLD.
We crudely screen for overweight or obese status based on the body mass index (BMI). This measures your weight, relative to your height.
BMI is not a perfect way to assess if you are obese or overweight. This is because it cannot differentiate between muscle, fat, bone or water weight. For example, majority of NFL players have a BMI that places them in the overweight or obese category, however, as athletes, they have an incredible amount of muscle mass and very little body fat. As a result, they are actually very fit.
Diagnosis
Most patients with MASLD have no symptoms. MASLD is often discovered after finding abnormal liver results on blood work tests, and/or fat buildup on imaging tests (ultrasound, CT scan, MRI) ordered for other reasons. The diagnosis is confirmed after other causes of fat buildup in the liver have been ruled out.
Once a diagnosis has been made, it is important to determine how much scarring or fibrosis is present in the liver. This is done preferentially using a new, non-invasive technique, called elastography to help detect how much fat and scar tissue are present in the liver. Elastography measures the stiffness of the liver, using it as a surrogate of scarring. Elastography has a very good accuracy in predicting scarring or fibrosis.
Through the COMET Clinic, our patients have access to several options including:
- Vibration-Controlled Transient Elastography (FibroScan),
- Shear-Wave Elastography, and
- Magnetic Resonance Elastography (MRE).
Alternatively, a liver biopsy or sampling of liver tissue, can also be considered to assess the amount of fat and scar tissue in the liver.
