Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease, or NAFLD, is the accumulation of excess fat in the liver not associated with alcohol consumption. The disease begins with simple obesity of the liver and can progress to a life-threatening condition called cirrhosis of the liver. With cirrhosis of the liver, the liver cells degenerate into tissue similar to the tissue from which scars (scars) form and the organ can no longer function normally. NAFLD is the most common form of liver disease in the world today.

In the United States, at least 30% of adults and up to 10% of children over 2 years of age have NAFLD. With obesity as a common comorbidity, the incidence of NAFLD has doubled in the past two decades and may soon surpass infection with hepatitis C as the leading cause of liver transplantation in the United States.

Spectrum of diseases

NAFLD is an ambiguous concept that includes several types of diseases with varying degrees of severity. In its simple form, NAFLD has no symptoms, only obesity, which is an excess of triglycerides in the liver. As many as 30% of people with NAFLD go on to non-alcoholic steatohepatitis or NASH, a severe form of fatty liver disease characterized by an inflammatory process. Often, the characteristic features associated with NASH are not observed. Some patients complain of fatigue and discomfort under the right hypochondrium. Many people with NASH continue to develop liver fibrosis or scarring. As fibrosis develops, it can develop into liver cirrhosis. Ultimately, this can lead to progressive chronic liver failure, liver cancer and even death.

Risk factors and causes

NAFLD is most common in people with obesity or type 2 diabetes. At least half of people with type 2 diabetes and about 90% of people with BMIs of 35 and above have some degree of NAFLD. These are all serious predisposing factors for insulin resistance. The risk of developing cardiovascular diseases increases.

Insulin resistance results in an excess of free fatty acids in the bloodstream and increased fat deposition in the liver. Most people with NAFLD have at least one indicator of metabolic syndrome and about one-third have all five indicators: high blood sugar, high blood pressure, low HDL (good cholesterol) cholesterol, high triglycerides, and an increase in waist circumference ...

The most common causes of NAFLD are: high blood cholesterol levels, polycystic ovary syndrome, temporary respiratory arrest during sleep, and thyroid dysfunction. Aggravating factors are obesity, a sedentary lifestyle, diabetes and poor nutrition.

Less common causes of NAFLD include certain medications, infections, genetic disorders that affect metabolism, poor diet, and rapid weight loss.

The relationship between NAFLD and cardiovascular disease

Disease progression across the NAPL spectrum is not well defined. Insulin resistance plays a significant role in the development of liver abnormalities, as does oxidative stress with inflammation. Zachary Henry, M.D., assistant professor of gastroenterology and hepatology at the University of Virginia, notes that in most of his patients, NAFLD worsens when the metabolic syndrome worsens. Moreover, the development of NASH can cause a dangerous link between increased insulin resistance and rapid disease progression across the NAFL spectrum.

Not all patients have the same disease. “There are many patients who are likely to have a genetic predisposition to the disease, regardless of metabolic syndrome,” says Henry.

Cardiovascular disease is one of the leading causes of death among people with NAFLD. Research shows that NAFLD increases the risk of cardiovascular disease by contributing to blood vessel dysfunction, inflammation, oxidative stress, and high cholesterol and triglyceride levels. The disease can also cause metabolic disorders.

Screening and Diagnosis of NAFLD

Screening begins with a blood test to measure liver enzymes, but complete diagnosis requires imaging of the liver, usually with ultrasound. Doctors often prescribe imaging tests for high-risk patients with elevated liver enzymes, such as type 2 diabetes, metabolic syndrome, sleep apnea, and BMIs of 35 or higher. However, the condition of patients is probably underestimated, since many patients with NAFLD have normal liver enzyme levels. Henry advocates imaging all patients at risk. This is a rather expensive procedure in the healthcare system, therefore, these studies recommend patients with elevated levels of liver enzymes.

A liver biopsy is needed to determine if the patient is simply obese or is progressing to NASH, fibrosis, or cirrhosis. Under the microscope, the sampled (discrete) liver tissue looks identical whether the patient has fatty liver from alcohol use, insulin resistance, or some other cause. The diagnosis of NAFLD is made primarily by eliminating excessive alcohol consumption.

NAFLD treatment

There are currently no specific FDA-approved drugs for the treatment of NAFLD. Meanwhile, lifestyle changes, weight loss, healthy eating and physical activity include not only treating liver disease, but also related conditions such as insulin resistance and others.

“Early intervention can prevent and even reverse NAFLD,” says Christine Kirkpatrick, MS, manager of Wellness Nutrition at the Cleveland Clinic and author of Lean Liver. The bottom line, he said, is to draw the attention of patients to concomitant circumstances such as high blood sugar.

Weight loss

As with the condition associated with insulin resistance, even small weight loss improves NAFLD. At Virginia Medical University, Mary Lou Perry MSc works with a multidisciplinary team that promotes healthy lifestyle habits and encourages weight loss of 7 to 10% of original body weight. Perry notes that the degree of improvement in well-being is proportional to the amount of weight lost. However, the rapid weight loss of more than 3.5 pounds per week, with its high flow of fatty acids to the liver, can worsen inflammation in NASH and exacerbate the disease.

Healthy eating

Research has not found an ideal diet for NAFLD. As such, the recommendations of the American Diet Guidelines (2015–2020) are relevant. One of the diet options that are popular with healthcare professionals is the Mediterranean diet. Studies have shown that this diet results in changes in both insulin resistance and liver fat content compared to a low fat, high carbohydrate diet, even without weight change.

The following foods deserve special attention as they influence the disease and are often asked by patients.

Alcohol

Minor use is not contraindicated for persons suffering from cardiovascular disease and hypersensitivity to insulin. However, it is not known whether these benefits of alcohol extend to patients with NAFLD, or whether a small amount of alcohol is also harmful. The American Liver Foundation and some doctors advise people with NAFLD to avoid alcohol altogether. In the absence of clear guidelines, patients with NAFLD should adhere to the American Heart Association's daily rate of one sip for women and two sips for men.

Coffee

Drinking coffee can reduce the severity of NAFLD due to its anti-inflammatory and antioxidant properties.

Green tea

Green tea rich in polyphenols. Drinking green tea can improve NAFLD.

Sugar beverages

Research shows that consuming sugary drinks is associated with a greater risk of NAFLD.

Dietary supplements

There is little evidence for the use of dietary supplements in the treatment of NAFLD. Some people may try unconventional treatments like milk thistle or green tea extract. At the same time, it should be borne in mind that dietary and herbal supplements cause liver toxicity in 20% of cases.

Physical activity

Cardio exercise and strength training improve insulin resistance and NAFLD. Without clear advice from your doctor, it is reasonable to use federal guidelines that allow you to engage in at least 150 minutes of moderate-intensity aerobics and two strength training sessions per week.

N.V. Nauchik