Serum Adiponectin Levels And Influencing Factors In Type 2 Diabetes Mellitus Patients With Nonalcoholic Fatty Liver Disease

Background and Aim: The prevalence of non-alcoholic fatty liver disease(NAFLD) in patients with type 2 diabetes mellitus(T2DM) is much higher than that of the general population. Both T2DM and NAFLD are closely related to obesity. Secreted by adipose tissue, adiponectin has the property of reversing dislipidemia, improving insulin sensitivity and liver protection, which is also closely related to oxidative stress. Malondialdehyde(MDA) is the final product of lipid peroxidation. Malondialdehyde level is commonly known as a marker of oxidative stress. The levels of serum adiponectin and malondialdehyde were measured in normal control group(NC group), nonalcoholic fatty liver disease group(NAFLD group), type 2 diabetes mellitus group(T2DM group), and type 2 diabetes mellitus with nonalcoholic fatty liver disease group(T2DM with NAFLD group). Serum levels of adiponectin and malondialdehyde were detected. The relationship between adiponectin and MDA and related clinical factors were analyzed to investigate the possible role of adiponectin and oxidative stress in the pathogenesis of T2DM with NAFLD patients.Methods: There were 34 cases(male 19, female 15) in NC group, 30 cases(male 16, female 14) in NAFLD group, 36 cases(male 19, female 17) in T2DM group and 33 cases(male 18, female 15) in T2DM with NAFLD group. Serum levels of adiponectin were measured by enzyme-linked immunosorbent assay(ELISA), and serum concentrations of malondialdehyde(MDA) were detected using thiobarbituric acid method. Fasting plasma glucose(FPG), glycosylated hemoglobin(Hb A1c), fasting insulin(FINS), alanine aminotransferase(ALT), aspartate aminotransferase(AST), gamma-glutamyl transferase(GGT), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C) were also measured. Insulin resistance index was calculated by homeostasis model assessment of insulin resistance(HOMA-IR) as(fasting insulin m U/L) ×(fasting plasma glucose mmol/L) / 22.5. Body mass index(BMI) was calculated as weight(kg) divided by height squared(m2).Results: FPG, Hb A1 c, FINS, HOMA-IR, ALT, GGT, TC and LDL-C were significantly higher, while BMI and HDL-C were lower in T2DM with NAFLD group than those in NAFLD group(P<0.05 respectively). FINS, ALT, AST, TG, GGT, TC and LDL-C were higher in T2DM with NAFLD group than those of T2DM group(P < 0.05 respectively). Serum adiponectin levels of T2DM with NAFLD group decreased compared with NC group, NAFLD group or T2DM group(P<0.05 respectively); while the MDA levels of T2DM with NAFLD group were significantly higher than those in NC, NAFLD or T2DM group(P<0.05 respectively). The adiponectin levels were negatively correlated with BMI, MDA, TG, TC, LDL-C, FPG, Hb A1 c, FINS and HOMA-IR, and positively correlated with HDL-C. Multiple stepwise regression analysis showed that Hb A1 c and MDA were the independent risk factors of serum adiponectin levels in NAFLD group and T2DM with NAFLD group.Conclusions : 1. The T2DM with NAFLD group patients have more serious glycometabolism disorder, dyslipidemia, insulin resistance, degree of oxidative stress, and liver injury than the NAFLD or T2DM group patients. 2. The lower adiponectin level may play an important role in the pathogenesis of T2DM with NAFLD. 3. The glucose metabolism disorder and oxidative stress may also play a certain role in the pathogenesis of T2DM with NAFLD.