While it’s normal and healthy for the liver to contain some fat, if more than 5 to 10 percent of the liver’s weight is fat, it’s called a fatty liver, also known as steatosis. (1) When inflammation and liver cell damage occur along with fat in the liver, it’s called nonalcoholic steatohepatitis (NASH). NASH is a type of nonalcoholic fatty liver disease, and it affects about 1 out of 5 people with NAFLD. (2) It’s estimated that by 2030, NASH will be the number one reason for liver transplants in the United States. (3)
Nonalcoholic Fatty Liver Disease vs. Alcohol-Associated Fatty Liver Disease
NAFLD and alcohol-associated fatty liver disease are the two most common forms of liver disease in the United States right now, according to Christina Lindenmeyer, MD, a gastroenterologist at the Cleveland Clinic in Ohio. The primary difference is indicated in the names of the diseases: Alcohol-associated fatty liver disease is linked with alcohol ingestion, and nonalcoholic fatty liver disease is associated with metabolic syndrome — a group of health risks that includes obesity, high cholesterol, high blood pressure, high blood sugar, and a large waistline — says Dr. Lindenmeyer. The main way the two diseases are diagnosed is through a person’s medical history and how much alcohol the person consumes.
Risk Factors for Nonalcoholic Fatty Liver Disease
The cluster of conditions known as metabolic syndrome increase the risk of developing NAFLD and can include:
Being Overweight The entire spectrum of obesity, ranging from overweight (body mass index, or BMI, of 25 or over), to obese (BMI of 30 or greater) and severely obese (BMI of 35 or greater) is associated with NAFLD. (4)Large Waist Circumference A study presented April 2016 at The International Liver Congress in Barcelona, Spain, found that waist circumference could be a better predictor of complications of NAFLD than BMI. (5) Women whose waist measured greater than 35 inches and males whose waist measured more than 40 inches were at a greater risk.Type 2 Diabetes It is estimated that as many as 2 out of 3 people with type 2 diabetes have NAFLD. The relationship between these two conditions is considered bidirectional, which means that having NAFLD puts a person at higher risk for developing type 2 diabetes as well. (1)Dyslipidemia High triglyceride levels and low levels of the “good” cholesterol, called high-density lipoprotein (HDL), are common in people with NAFLD. (1)High Blood Pressure Even in the absence of other metabolic risk factors, hypertension, also known as high blood pressure, is associated with a higher risk of developing NAFLD, according to a cohort study. (6)Older Age The incidence of fatty liver increases with age. Peak prevalence in men happens between ages 40 and 49, and for women between ages 60 and 69, according to research. (7)
FatigueWeaknessWeight lossLoss of appetiteNauseaAbdominal pain
Nonalcoholic Fatty Liver Disease Diagnosis
The screening tests for NAFLD are simple blood tests that check liver biochemistries or tests of the liver function, says Lindenmeyer. These blood tests are often done as part of a routine physical exam. “If those results are abnormal, then frequently we follow that up with some sort of imaging study of the liver, whether it be an ultrasound, a CT (computerized tomography) scan, or an MRI (magnetic resonance imaging),” she says. A Fibroscan device, which works like an ultrasound, may also be used to estimate the amount of scarring, or fibrosis, in the liver.
Nonalcoholic Fatty Liver Disease Treatment
Although there isn’t an FDA-approved drug to treat NAFLD, there are drugs in the pipeline that show promise but aren’t yet available, says Carlos Romero-Marrero, MD, director of the Liver Disease Center at Cleveland Clinic Florida, Tradition Hospital, in Port St. Lucie. There is some evidence that weight-loss drugs such as semaglutide (Rybelsus) may be helpful in treating NAFLD and its more severe form, nonalcoholic steatohepatitis. If a person with severe NAFLD is not able to lose weight through lifestyle changes, doctors may recommend bariatric (weight-loss) surgery. Along with losing weight, recommendations for managing NAFLD include: (1)
Consuming 800 units of vitamin E dailyRegular aerobic exercise of at least 50 minutes, three times per weekEliminating alcoholIf you have diabetes, tight control of glucose levels
People with cirrhosis are at a greater risk of developing liver failure and liver cancer. NAFLD and NASH are both associated with a higher-than-usual risk of cardiovascular disease. Heart disease is actually the leading cause of death for people with NAFLD. (9)
