Abstract

A COMPARITIVE STUDY ON NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD)-REVIEW

Akhila Yerubandi*, Sivakshari Makkapati and Sreenu Thalla

ABSTRACT

Non-Alcoholic Fatty Liver Disease (NAFLD) is a widespread liver disorder in the world in both developed and developing countries. It is the condition where the accumulation of lipids/fats in the liver occurs, primarily triglycerides in an individual who do not have any history of alcohol consumption in significant amounts (<20g ethanol/day) and known liver diseases.[2,3,4] It is known to cause abnormal liver function tests. It is a significant cause of cryptogenic liver cirrhosis, commonly observed in middle age and old age people. It is not indicated for a specific gender. The natural history of the disease is still unknown.[1] The clinical spectrum of NAFLD is wide-ranging and spans NAFL [Non-alcoholic fatty liver] to non-alcoholic steatohepatitis [NASH]. Fibrosis, cirrhosis, and hepatocellular carcinoma are the advanced stages of NAFLD.[6] The significant factors associated with NAFLD are obesity; type 2 Diabetes Mellitus, Insulin Resistance, Hyperglycemia, and Hypertriglyceridemia. NAFLD is also seen in individuals with healthy BMI [Body Mass Index] who do not necessarily have insulin resistance-associated metabolic disorders.[7] Obesity is having the risk of developing cardiovascular disease, Hyperlipidemia, Hypertension, NAFLD, and also a metabolic syndrome that is characterized by Insulin Resistance. NAFLD is highly recognized as a significant reason for the occurrence of liver-related morbidity and mortality among 15-40% of the general population.[4] Healthy liver contains <5% of fat content whereas NAFLD liver contains 50-80% of fat content. NASH [Non-alcoholic Steato hepatitis] is a type of metabolic liver disease in which fatty changes (Steatosis) are associated with lobular inflammation. NAFLD ranges from simple Steatosis (4-8 weeks) through NASH (16-24 weeks) to advanced Cirrhosis and HCC (52 weeks). NASH can be reversible but Cirrhosis, and HCC conditions are irreversible.[2,8] The pathophysiology behind this mechanism is increased lipolysis and increased delivery of fatty acids from adipose tissue to the liver in the form of triglycerides.[4] 10-29% of patients who are suffering from NASH develop cirrhosis within ten years. Early detection may help prevent cirrhosis of the liver that can be detected by ALT (Alanine Transaminase) levels.[3] Invasive biopsy, MRI, and CT are expensive detection parameters, where Ultrasonography (USG) is inexpensive but detect <10% of Hepatic Steatosis.[4] The fibro scan value is alternate to liver biopsy in identifying the staging of fibrosis, but it cannot detect etiology of disease.[3] Adult Treatment Panel III (ATP III) on detection, evaluation, and treatment of high blood cholesterol in adults recommends the use of 5 variables for diagnosis of Metabolic Syndrome. The variables include waist circumference, serum triglycerides levels, serum high-density lipid cholesterol levels, blood pressure, and fasting blood sugar levels. ATP III criteria explain metabolic syndrome as the presence of 3 of 5 criteria.[4] NAFLD is now considered the hepatic feature of metabolic syndrome.[5] Most of the NAFLD patients have the risk of 20-50% fibrosis, 30% cirrhosis, and 5% Hepato-Cellular Cancer (HCC). Early diagnosis and treatment help prevent complications. Non-Pharmacological treatment, such as dietary modifications and exercise, plays a vital role in the treatment of NAFLD.[1] Weight loss and diet restriction reduces free fatty acid supply to the liver, improves Insulin Sensitivity, decreased adipose tissue inflammation. Moderate intensity of aerobic exercise along with diet changes normalizes ALT in NASH. The decrease in BMI of 3 points over three months period improves Hepatic Steatosis in a few studies.[3]

Keywords: .