By GUY NEFF, MD, MBA
Fatty liver disease is a silent epidemic, affecting millions of Americans and imposing significant financial burden on the U.S. healthcare system. Not simply a result of alcohol consumption, as many believe, non-alcoholic fatty liver disease (NAFLD) is the most common type of liver disease in the Western world -- associated with obesity, insulin resistance, diabetes and other metabolic risk factors and directly related to too much fat in the liver cells.
While Florida has the 15th lowest adult obesity rate in the nation, it has the 13th highest obesity rate for youth ages 10 to 17, and the overall obesity rate is up from 11.4 percent in 1990 to 28.4 percent in 2018.
The American Liver Foundation estimates that about 100 million Americans -- over 30 percent of the U.S. population -- have NAFLD. NAFLD encompasses a spectrum of disease, ranging from-simple steatosis, to steatosis with inflammation (nonalcoholic steatohepatitis or NASH), to NASH plus advancing fibrosis to cirrhosis. More than one-third of children and adults in the United States are obese and more than 20 million Americans have diabetes, resulting in a large at-risk population for NAFLD. Approximately two to five percent of patients with NAFLD progress to NASH, among whom a subset will develop cirrhosis and cirrhosis-related complications including hepatocellular carcinoma (HCC).
If this trend continues, NAFLD will become the main indication for liver transplants in the country, with the number of healthy livers available for transplants likely to decline. Children as young as five are also developing fatty liver disease through over consumption of sugars, sodas, fructose, corn syrup and lack of exercise.
Identifying At-Risk Patients
An interim look at an ongoing study of 10,000 patients with no history of liver disease was conducted in community-based endoscopy centers by the Florida Research Institute (FRI) a division of Florida Digestive Health Specialists (FDHS). Only 43 percent of patients evaluated had what is considered normal livers based on a FibroScan® assessment alone, while the remainder had some form of liver abnormality, ranging from elevated liver fat to liver fibrosis, including 13 percent suspected of having undiagnosed liver fibrosis or cirrhosis. Important to note is that the vast majority of patients had no symptoms. While further workup is recommended to confirm the extent of liver disease in these patients, this analysis of the first 367 patients suggests a significant rate of undiagnosed NAFLD in the population studied.
This prospective study evaluated patients, with no history of liver disease, undergoing routine endoscopic procedures between June 2017 and January 2018 versus a matched control of patients not undergoing a liver health assessment. Patients were risk stratified based on FibroScan®, which utilizes Vibration Controlled Transient Elastography (VCTE™) and CAP ™, surrogate scores of liver fibrosis and liver fat, respectively. The study team examined electronic medical records within 90 days after the procedure to determine and compare prevalence of NAFLD.
Results showed 53 percent of patients studied had excess fat in their livers as identified by the CAP, of which 64 percent likely had grade 3 liver fat, as identified by a CAP score of ≥279 dBm. More concerning, only 43 percent of patients evaluated had what we would consider normal livers (stiffness <7kPa and CAP <248dBm). These results underscore the importance of identifying asymptomatic patients who may be at risk for advancing disease for earlier intervention. It is alarming to see this high prevalence of disease, a dramatic rise from our observations in the last decade and indicative of the critical need for ongoing assessment.
These results underscore the importance of identifying asymptomatic patients who may be at risk for advancing disease for earlier intervention, while the increasing prevalence of disease shows the importance of regular assessment.
NAFLD can be reversible if caught in the early stages and accompanied by lifestyle changes. What's more, simple screening and early detection with available non-invasive technologies can help to prevent more serious conditions, such as end-stage liver disease or liver cancer.
Risk Factor for Pre-Diabetes
NAFLD is the result of poor eating habits and a sedentary lifestyle. In some cases, the fat in the liver cells builds up to the point where the liver cells swell and eventually cause inflammation. But there are usually no symptoms at this point. A recent study suggested that prediabetics with fatty liver were twice as likely to progress to overt type 2 diabetes as prediabetics without NAFLD.
Nationally, more than half of adults with NAFLD are obese, and 30 percent or more are overweight. Conversely, overweight or obesity is responsible for causing about 85 percent of fatty liver disease. Unfortunately, obesity is also a risk factor for diabetes.
Obesity can contribute to insulin resistance, which results in a buildup of blood sugar and increases the amount of free fatty acids circulating in the blood or accumulating inside the liver cells. The Hepatitis B Foundation also advises that buildup of fat in the liver is common in those with Type 2 diabetes, increasing the risk of liver cirrhosis and liver cancer. Furthermore, NAFLD has been found to be a strong and independent risk factor for pre-diabetes in the general adult population.
This combination of conditions can be pernicious, especially because until the extent of cirrhosis from NAFLD becomes quite severe, it has no symptoms. If you have it, most likely you have no clue that your health is deteriorating. With the advent of screening and greater focus on preventive care, this situation is changing.
The Value of Non-Invasive Screening Methods
A growing number of healthcare providers have started adopting non-invasive screening methods that can detect NAFLD in the absence of indications or warning signs. FibroScan® is one such innovation. This rapid and painless approach can be performed in the doctor's office as part of an annual exam, and is covered by Medicare, Medicaid and other insurance plans.
A 10-minute screening offers quick insight into liver health - measuring liver fat content and liver stiffness (associated with fibrosis and cirrhosis). Test scores provide immediate information the physician can use to make a referral to a specialist or recommend additional assessments. In fact, a yearly NAFLD screening may become standard practice similar to a mammography or A1C blood sugar testing.
The point of these screening tools is that they can measure the amount of liver stiffness and fat to better target more expensive or more invasive diagnostic procedures - saving time and resources for people who don't need to undergo additional assessment. FibroScan® is a viable option for screening; its portable, can be operated by a medical assistant and interpreted by the healthcare professional at the point of care delivery, making it a valuable accompaniment for managing patients.
Guy Neff, MD, MBA, is the Director of the Florida Research Institute