Nonalcoholic steatosis is the most common cause of liver disease in the USA. Try your hand at our half dozen questions on the hepatic cousins NAFL and NASH.
Nonalcoholic fatty liver has become the most common cause of hepatic disease in the United States and other western industrialized countries. Increased prevalence is linked to the parallel rise in overweight and obesity.
Nonalcoholic fatty liver disease (NAFLD) is divided into nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). NAFL is characterized by hepatic steatosis without evidence of inflammation; in NASH, hepatic steatosis is associated with hepatic inflammation that is histologically is indistinguishable from alcoholic steatohepatitis.
Time to find out what you know about each with the 6-question quiz that follows.
1. About how many Americans suffer from nonalcoholic fatty liver disease (NAFLD)?
A. 10 to 25 million
B. 25 to 50 million
C. 50 to 75 million
D. 75 to 100 million
Answer: D. 75 to 100 million.
Many of those with NAFLD may not be aware of their condition. About 30% of Americans may suffer from NAFLD, while 5% may suffer from nonalcoholic steatohepatitis (NASH). Patients with NASH are more likely to progress to cirrhosis, portal hypertension, and liver failure. People with NAFLD have an increased risk for hepatocellular carcinoma. NAFLD accounts for the most rapidly increasing indication for liver transplant. Cardiovascular disease and malignancy cause half of deaths in NAFLD, and cirrhosis comes in as the third leading cause of death.1
2. The single most important way to prevent NAFLD is:
A. Weight loss
B. Lowfat diet
C. Smoking cessation
D. A and C
Answer: A. Weight loss
The best way to reverse NAFLD in overweight and obese patients is also through weight loss along with lifestyle modification. In obese patients, the goal is usually to reach a sustained weight loss of 7% to 10% by combining a balanced, calorie-restricted diet and increased exercise. Diets high in sweet beverages, fructose, or meats have been linked to increased risk of NAFLD. Weight loss in patients with NAFLD can also improve serum insulin levels, liver function, and quality of life. Losing up to 1 kg/week is thought to be safe for patients with NAFLD. More rapid weight loss has been linked to worsening of liver disease.2
3. Bariatric surgery can improve NASH, but rarely results in total resolution.
Answer: B. False
Gastric bypass surgery can improve liver function and histology, through well-known effects on weight loss and perhaps through improving factors that influence liver fibrosis such as growth factors and inflammatory mediators. In a recent meta-analysis that included 15 studies looking at bariatric surgery and NAFLD, 91% of patients had improved steatosis after bariatric surgery, 65.5% had decreased fibrosis, and 70% had total resolution of NASH. Most studies were prospective and used Roux-en-Y surgery.3
4. Which of the following may increase the risk for NASH?
A. Central abdominal obesity
C. Insulin resistance
E. All of the above
Answer: E. all of the above.
Features of the metabolic syndrome are linked to increased risk for NASH and more progressive disease. Metabolic dysfunction is linked to more advanced disease, but progression rates can vary widely. Some patients have only minimal progression over a decade, while others may advance to fibrosis or cirrhosis within five years or less.1
5. Which of the following have shown efficacy in treating NAFLD?
A. Vitamin E
D. All of the above
Answer: D. All of the above.
Even though the FDA has yet to approve a drug for NAFLD, vitamin E, pioglitazone, and pentoxifyline have all proven effective treatment. Patients with heart failure and/or postmenopausal bone loss should not receive pioglitazone. The drug is associated with weight gain of about 3 to 5 kg, and may possibly increase the risk for bladder cancer. Though research suggests that vitamin E can improve hepatic steatosis, inflammation, insulin resistance, and liver enzymes, there is not enough evidence to support its use in patients with diabetes or cirrhosis. At least three small RCTs have suggested that pentoxifyline can improve liver fibrosis. Drawbacks of pentoxifyline include pruritus and lipid abnormalities. None of these treatments have shown efficacy in over 50% of patients.1
6. Approximately what percentage of patients with NASH cirrhosis develop decompensated cirrhosis over 10 years?
Answer: C. 45%
These patients most commonly present with ascites, though they sometimes may be seen with variceal bleeding or hepatic encephalopathy. Renal failure is the most important predictor of death. Patients with compensated cirrhosis should be monitored twice a year for decompensation and hepatic function. Screening for varices should begin upon initial diagnosis of cirrhosis. Patients with decompensated cirrhosis should be referred and evaluated for liver transplant.1
Rinella ME. Nonalcoholic fatty liver disease: a systematic review. JAMA. 2015 Jun 9;313(22):2263-73. doi: 10.1001/jama.2015.5370.
Mummadi RR, Kasturi KS, Chennareddygari S, et al. Effect of bariatric surgery on nonalcoholic fatty liver disease: systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2008 Dec;6(12):1396-402. doi: 10.1016/j.cgh.2008.08.012. Epub 2008 Aug 19.
Sanyal AJ, Banas C, Sargeant C, et al. Similarities and differences in outcomes of cirrhosis due to nonalcoholic steatohepatitis and hepatitis C. Hepatology. 2006 Apr;43(4):682-9.