NASH

Candy is dandy, but liquor is quicker

 

How easy for those who do not bulge, to not overindulge

- Ogden Nash

 

Ogden Nash was a famous American poet and humorist.  Unfortunately the NASH to be discussed in this column is not as well known and certainly is not humorous. 

 

NASH (or non-alcoholic steatohepatitis) is a subcategory of non-alcoholic fatty liver disease (NAFLD). NAFLD is the most common chronic liver disease, affecting about 25% of adults worldwide.  It occurs when fat builds up in the liver, without associated liver damage. It can progress to NASH, which is a fatty liver but with inflammation, liver injury and scarring (fibrosis).  NASH is quite serious and can lead to cirrhosis (liver failure) or liver cancer. NASH is the most common reason for liver transplantation. About 20-30% of patients with NASH progress to cirrhosis or cancer.  NASH is seen in about 3-5% of people around the world. NAFLD is the liver manifestation of the metabolic syndrome (a systemic condition characterized by obesity, diabetes, high blood pressure and abnormal lipids, especially high triglycerides and low HDL).  Because of this association, NAFLD is linked to cardiovascular disease and both conditions are considered the end-organ damage of the metabolic syndrome.  NAFLD is diagnosed by liver ultrasound or liver biopsy, both methods show the fatty infiltration of the liver. Liver enzymes in the blood (alanine transaminase, ALT, and aspartate transaminase, AST) are mildly elevated. To make the diagnosis, daily alcohol consumption must be less than 30 grams in men and 20 grams in women per day (for perspective one glass of wine is about 17 grams).

 

There are several mechanisms linking NAFLD and cardiovascular disease.  In NAFLD, a diet high in cholesterol and saturated fat leads to high triglycerides in the blood and fat deposition in the liver. The same high triglycerides and low HDL cholesterol cause plaque build up in the heart arteries and blockage.  In diabetic patients with metabolic syndrome, persistently high sugar levels lead to vascular inflammation and coronary artery disease. Fat is present in the liver, but is also deposited around the heart.  The heart arteries run through this fatty tissue, exposing them to inflammation and subsequent blockage.

 

NAFLD is associated with higher mortality compared to the general population.  With more advanced disease (more fibrosis, cirrhosis, cancer) the higher the death rate.  Patients with NAFLD are also at higher risk for developing heart attack, stroke, angina (heart related chest pain) or cardiac death.  Patients with more advanced disease (especially more severe liver fibrosis) are at higher risk for developing cardiovascular disease. Because of this, all NAFLD patients should be evaluated for their risk for heart disease. 

 

NAFLD is treated with weight loss, exercise, diet and medication. A total body weight loss of about 10% is needed to reverse the liver fibrosis. However, weight loss alone is not sufficient to reduce the cardiac risk for NAFLD patients, other lifestyle modifications are necessary. Exercise is needed and the recommended amount is 150-200 minutes per week of moderate exercise. This includes both aerobic activity (“cardio”) and resistance (weight training).  Following a diet high in calories, saturated fats, and refined carbohydrates can lead to obesity, type two diabetes, NAFLD, metabolic syndrome and cardiovascular disease. In addition, consuming sugar-sweetened beverages that are high in fructose (a type of sugar) produces the metabolic syndrome.  Patients with NAFLD should restrict foods high in fructose, saturated fats and simple carbohydrates. Following a Mediterranean diet was shown to reduce the fat in the liver. In addition, the timing of food consumption is a factor. Intermittent fasting, with no food intake for 10 to 16 hours, helps reduce unhealthy metabolic abnormalities. This strategy involves eating during the day with nothing consumed after 6 PM.  Medications may also be beneficial for reversing NAFLD. In patients with concomitant diabetes, metformin and sodium glucose linked transport inhibitors (SGLT2 agents, such as Jardiance or Farxiga) reduce fat accumulation and decrease inflammation. These agents also reduce the risk for heart attack and congestive heart failure in diabetics. All patients with NAFLD should have their cholesterol lowered with statins. This has been proven to be safe and effective in NAFLD (despite the mild liver enzyme elevation).  Lastly, new agents that block key metabolic, inflammation and fibrosis pathways in NAFLD are being developed.

 

So, the cardiologist’s retort to Ogden Nash is that liquor may be quicker, but candy is not benign. Enjoy the holiday season, but try to limit the candy, fatty foods and sugar-sweetened beverages.  And no matter what your weight, try not to overindulge. Your heart and your liver will thank you.