The relationship between nonalcoholic fatty liver disease and insulin resistance

Objective To investigate the disorder of lipid metabolism, degree of insulin resistance in patients of nonalcoholic fatty liver disease(NAFLD) and relationship of NAFLD with insulin resistance and level of tumor necrosis factor alpha(TNF-α). Methods The investigation used a case control study. Serum lipids, free fatty acid(FFA), TNF-α, serum glucose and insulin(fasting and 2-hour postprandial) were measured in patients of 67 type 2 diabetes with fatty liver(DF), 33 type 2 diabetes without fatty liver(NDF), 21 fatty liver(FL) and 18 control subjects(NC). 26 DF patients and 10 control subjects were evaluated about hepatic fat content by using CT. Results The result showed that weight(W), body mass index(BMI), waist circumference(W1), hip circumference(H1), waist-hip ratio(WHR), serum cholesterol(TC), serum triglycerides(TG), alanine aminotransferase(ALT), aspartate aminotransferase(AST), HOMA-IR and TNF-α were significantly more elevated in the groups of DF, FL compared with those of group NDF and NC(P0.05).The levels of fasting blood glucose(FBG), 2-hour postprandial blood glucose(2 h BG), fasting serum insulin(FIns), 2-hour postprandial serum insulin(2 h Ins) in patients of group F were significantly higher than those of group NC(P0.05). FFA was obviously increased in DF patients compared with control subjects(P0.05). Multiple stepwise regression analysis showed that FBG, TG, BMI, and fatty liver were the mainly risk factors for insulin resistance in patients of NAFLD. The significant difference of TC,TG and TNF-α was confirmed in patients of different degree of hepatic steatosis(P0.05). Conclusion The study confirms that insulin resistance is uniformly present in subjects with fatty liver, even after correcting other influence factors. FBG, TG, BMI, and fatty liver were the mainly risk factors for insulin resistance in patients of NAFLD.