Serum phospholipid omega-3 polyunsaturated fatty acids and insulin resistance in type 2 diabetes mellitus and non-alcoholic fatty liver disease.

AIMS: To investigate the relationship between serum phospholipid omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and insulin resistance (IR) in patients with type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD). METHODS: 51 patients with T2DM and NAFLD (T2DM+NAFLD group), 50 with T2DM alone (T2DM group), 45 with NAFLD alone (NAFLD group), and 42 healthy control subjects (NC group) were studied. Serum ω-3 PUFA profiles were analyzed by gas chromatography, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and serum lipid concentrations were measured. Insulin resistance was assessed by the homeostasis model assessment method (HOMA-IR). RESULTS: HOMA-IR levels were higher in the T2DM+NAFLD group than in the T2DM, NAFLD and NC groups (p<0.05), as were ALT, AST, GGT, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations (p<0.05). Conversely, serum ω-3 PUFA levels were significantly lower in the T2DM+NAFLD group than in the other groups (p<0.05). The ω-3 PUFA level was negatively correlated with HOMA-IR, TC, LDL-C and TG. CONCLUSIONS: Serum phospholipid ω-3 PUFA levels were significantly decreased in patients with T2DM and NAFLD, and were negatively related with insulin resistance. Thus, reduced ω-3 PUFAs may play an important role in the development of T2DM and NAFLD.

[Serum omega-3 polyunsaturated fatty acid and insulin resistance in type 2 diabetes mellitus and non-alcoholic fatty liver disease].

OBJECTIVE: To investigate the relationship between serum omega-3 polyunsaturated fatty acid (omega-3PUFA) and insulin resistance (IR) in patients with type 2 diabetes mellitus and non-alcoholic fatty liver disease (NAFLD). METHODS: This trial involved 51 patients of type 2 diabetes mellitus with NAFLD (G4 group), 50 patients of type 2 diabetes alone (G3 group), 45 patients of NAFLD alone (G2 group) and 42 healthy control subjects (G1 group). Serum omega-3PUFA profile was analyzed with capillary gas chromatography. Insulin resistance was assessed by homeostasis model assessment (HOMA-IR). ALT, AST, gamma-glutamyltransferase (GGT) and serum lipids were measured. RESULTS: The levels of HOMA-IR were higher in G4 group than those in G3, G2 and G1 group (4.90 + or - 2.54 vs 2.38 + or - 1.23, 2.20 + or - 1.15, 1.13 + or - 0.42; P < 0.05). The level of ALT, AST, GGT, TC, TG, LDL-C were higher in G4 group than those in G3, G2 and G1 group (P < 0.05). The level of omega-3PUFA was significantly lower in G4 group than those in G3, G2 and G1 group (5.68 + or - 2.02 vs 7.17 + or - 2.38, 6.97 + or - 2.32, 10.08 + or - 2.76; P < 0.05). omega-3PUFA concentration was negatively correlated with HOMA-IR, TC, TG and LDL-C (r = -0.491, -0.376, -0.462, -0.408, P < 0.05). CONCLUSIONS: Serum omega-3PUFA is significantly decreased in patients with type 2 diabetes mellitus and NAFLD. Serum omega-3PUFA is negatively correlated with insulin resistance. omega-3PUFA plays a very important role in the development of diabetes mellitus and NAFLD.

[Effects of fenofibrate on gene expression of carnitine palmitoyltransferase 1 in liver and skeletal muscle and its influence on insulin sensitivity].

OBJECTIVE: To study the effects of fenofibrate (FF), a peroxisome proliferator activated receptor (PPAR) alpha activator, on the expression of carnitine palmitoyltransferase 1 (CPT-1) mRNA in liver and muscle and its influence on insulin sensitivity. METHODS: Thirty-two normal 8 week-old male SD rats were randomly divided into 3 groups: normal control group, fed with normal food for 3 weeks (NC group, n = 10), high fat diet group, fed with high fat food (HF group, n = 10), and high fat diet supplemented with FF group, fed with high fat food and given with gastric perfusion of FF (50 mg x kg(-1) x d(-1)) (FF group, n = 12). Fast serum triglyceride (TG) level was tested by automatic biochemical analyzer after 8-10 h fasting. Euglycemic-hyperinsulinemic clamp method was used to calculate the glucose infusion rate (GIR) so as to evaluate the insulin sensitivity. By the end of experiment the rats were killed with their internal organs taken out. The triglyceride (TG) contents of liver and skeletal muscle were measured using Folch method. Real-time PCR was used to detect the mRNA expression. of CPT-1 in the liver and skeletal muscles. RESULTS: As compared with the NC group, the TG levels of serum, liver, and skeletal muscle of the HF group were higher than those of the NC group by 0.45-fold, 2.14-fold, and 10.64-fold respectively. The GIR of the HF group was (6.2 +/- 0.8) mg x kg(-1) x min(-1), significantly lower than that of the NC group (15.8 +/- 2.1) mg x kg(-1) x min(-1), (P < 0.01), and that of the P < 0.01. The CPT-1 mRNA expression in liver of the HF group was not significantly different from that of the NC group (P > 0.05); the expression of CPT-1 mRNA in skeletal muscle of the HF group was lower than that of the NC group by 71% (P < 0.01). The CPT-1 mRNA expression in liver and skeletal muscle of the FF group were significantly higher than those of the HF group by 1.00 and 1.05 times respectively (both P < 05). The GIR was negatively correlated with the levels in the liver (r = -0.87, P < 0.01) and in the skeletal muscle (r = -0.78, P < 0.01). CONCLUSION: Fenofibrate promotes the oxygenation of fatty acids by up-regulating the CPT-1 mRNA expression in the liver and skeletal muscles, thus improving the insulin sensitivity.