Effect Of Dietary Fatty Acids On The Occurrence And Development Of Nonalcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a clinical and pathological syndromecharacterized by fatty degeneration of the liver parenchymal cells and fat piling withouthistory of excessive alcohol consumption. NAFLD can induce hypertension, atherosclerosis,diabetes and other chronic metabolic diseases, which is harm to human health. In recentyears, the number of patients with NAFLD increases every year, and is getting younger andyounger, according to statistics there are around20%to30%of adults suffering fromNAFLD. Currently, there are many programs for NAFLD treatment, but lacking of a clearlyefficient approach. Epidemiological survey found that fish oil rich in Omega-3polyunsaturated fatty acids (DHA and EPA) may play a key role in the development ofNAFLD. However, little information is available regarding to the Omega-3polyunsaturatedfatty acids interfere with the treatment of NAFLD population, especially Asian populationand the results are not consistent. Thus, this study first use case-control study to analyzelipid metabolism between NAFLD population and normal control subjects, to clarify therisk factors for NAFLD; then designing a randomized controlled trial for fish oilintervention in NAFLD patients to find out the affect of fish oil intervention on thedevelopment of NAFLD. This article will provide new experimental evidence for dietarynutrition interventions of NAFLD, which has important theoretical value and applicationprospects.The main method, results and conclusions are as follows:1. The cases-control study of NAFLD1.1The main methodsIn The First Affiliated Hospital of Third Military Medical University,105cases ofNAFLD patients diagnosed by ultrasound B, according to age, sex, place of residence andother information, selected the appropriate105health objects as the control group.Investigating the basic personal information of all of the subjects including: gender, age, residence, education level, household income average monthly, and measuring the height,weight, and calculate body mass index, fasting venous blood triglyceride，total cholesterol，high density lipoprotein cholesterol，low density lipoprotein cholesterol，gamma-glutamyltranspeptidase，alanine aminotransferase，glutamic-oxalacetic transaminase，fasting plasmaglucose，uric acid，creatinine testing, using gas chromatography to analyze the plasma freefatty acid composition.1.2Results:(1) BMI and serum ALT, AST, GGT, TC, TG, LDL-C, CR, UA concentrations ofNAFLD group were significantly higher (P <0.05).(2) Serum TG (OR=4.325) and high concentrations of BMI (OR=1.670) were riskfactors for NAFLD.(3) Plasma palmitic acid (C16:0) level of NAFLD was notably higher (P <0.05),linoleic acid (C18:2) and arachidonic acid (C20:4) level were lower than those of thecontrol group (P <0.05).(4) Elevation of plasma C16:0(OR=1.305) level increased the risk of NAFLD,however, increase of plasma C20:4(OR=0.241) level decreased the risk of NAFLD.2. The fish oil on the role of NAFLD2.1The main methodsA randomized double-blind controlled trial design,80NAFLD patients were randomlyassigned to placebo and fish oil group, the intervention time is three months. Beforeintervention, all of the subjects filled gender, age and other basic personal information.Using the24-hour recall method for dietary survey and all subjects performed physicalmeasurements before and after the intervention; fasting venous blood were used to test liverfunction, renal function, blood lipids, blood glucose and blood testing, using gaschromatography to analyze the plasma free fatty acid composition, adiponectin, tumornecrosis factor-α, fibroblast growth factor21, cytokeratin18level-M30and other cytokineswere measured by ELISA.2.2Results(1) Three months intervention can significantly reduce serum ALT, TG, TC and ApoBconcentrations (P <0.05).(2) Compared to placebo, plasma EPA (C20:5) and DHA (C22:6) levels of subjects in the fish oil group significantly increased after3months intervention (P <0.05).(3) After3months intervention, serum ADP concentration of the fish oil group notablyincreased, and the FGF21and CK18-M30concentration markedly decreased (P <0.05).3. Conclusion:(1) High serum triglyceride concentrations and BMI are risk factors of NAFLD.(2)Elevation of plasma palmitic acid(C16:0)level increases the risk of NAFLD,increase of arachidonic acid(C20:4) level can reduce the risk of NAFLD.(3) Fish oil intervention in patients with NAFLD three months significantly increasesplasma levels of EPA, DHA and serum adiponectin concentration and reduces serum alanineaminotransferase, triglycerides, cholesterol, apolipoprotein B, cytokeratin18-M30, andfibroblast growth factor21concentrations, indicating that fish oil intervention can improvelipid metabolism、cytokines、and liver function indicators of NAFLD.