The Epidemiological Survey Of NAFLD In Civil Servants Of Chongqing City And Intervention Studies In Rat Models Of NAFLD

Objective: To investigate the prevalence of NAFLD and related major risk factors among civil servants of Chongqing city. To study the mechanism of action of rosiglitazone and bezafibrate on NAFLD rats induced by high fat diet.Methods: A cross-sectional multiple-stage stratified analytic survey was performed in medical examination center of the first affiliated hospital of Chongqing university of medical sciences. Civil servants of Chongqing city were invited to participate in the Physical examination including serum biochemistry-profile and ultrasonographic examination of liver. forty-two SD rats were divided into control group, high fat diet group, RSG group and BEZ group. After the animal model of NAFLD was elicited by feeding rats high fat diet for eight weeks, RSG group and BEZ group were treated with RSG and BEZ for twelve weeks, respectively. BW was measured during the experiment. LW was measured after rats were killed. BG, TC, LDL, HDL, TG, ALT, AST, MDA, SOD, CRP were examined at the end of the experiment, the hepatic ultrastructure was observed with electron microscope and morphological changes were observed by light microscope. Immunohistochemistry was used to observe the expression of COX-2 protein .Results: (1) The prevalence of NAFLD was 20.9%. The mean age, BMI, WHR, waist circumference, FPG, UA, TG, SBP, DBP and the prevalence of overweight, obesity, central obesity, impaired fasting glycaemia(IFG), diabetes mellitus(DM), hypertriglyceridemia, mixed hypertriglyceridemia, primary hypertension, hyperuricemia in NAFLD group was significantly higher than those in control group(P<0.01). The level of low-density lipoprotein cholesterol(LDL-C) was significantly higher in NAFLD group than that in control group(P<0.05), while the level of HDL-C was opposite(P<0.01). The difference of the prevalence of hypercholesterolemia between the two groups wasn't significant(P>0.05). Stepwise logistic regression showed that the pathogenesis of NAFLD was positively correlated to waist circumference, TG, BMI, HDL-C, ages, sex and UA. (2) BW, LW, LW/BW, BG, TG, TC, LDL, ALT, AST, MDA and CRP in high fatty diet group were significantly higher than those in control group(P<0.01), while the levels of HDL-C and SOD were opposite (P<0.01). LW, LW/BW, BG, MDA, ALT, CRP in RSG group was significantly lower than those in high fatty diet group(P<0.01); while the levels of SOD and HDL were reverse (SOD:P<0.01, HDL:P<0.05). LW, LW/BW, BG, TG, TC, LDL, MDA, ALT in BEZ group was significantly lower than those in high fatty diet group(P<0.01); CRP was significantly lower than those in high fatty diet group(P<0.05); while the levels of SOD and HDL were opposite (SOD:P<0.01,HDL:P<0.05). (3) Main ultrastructural changes of high fatty diet group were lipid deposition in hepatocyte. (4) Light microscopy showed typical steatosis in high fatty diet group, while the degree of liver steatosis was significantly alleviated in RSG group and BEZ group. (5) Immunohistochemistry: COX-2 was not expressed in the liver of control group, hepatic expression of COX-2 in high fatty diet group was significantly higher than that in control group, while hepatic expression of COX-2 was decreased in RSG group and BEZ group than that in high fatty diet group.Conclusion: (1) The prevalence of NAFLD was 20.9% in civil servants of Chongqing city. Insulin resistance was the core of multiple metabolic disorders which accounted for NAFLD. (2) The rat model for NAFLD can be established sucessfully by feeding high fat diet, changes in glycolipid metabolism, oxidative stress and inflammatory reaction of NAFLD rats are similar to human beings, so NAFLD rats are ideal models to study human NAFLD. (3) RSG and BEZ can treat NAFLD effectively by improving glycolipid metabolism, oxidative stress and inflammatory reaction.