The Relationship Betwneen Leptin And The Type 2 Diabetes With Coronary Heart Disease And The Effects Of Hypoglycemic Drugs On The Leptin Level In Plasma

Objective:To investigate the effect of plasma leptin on the occurrence and development of coronary heart disease (CHD) and their correlations in patients with type 2 diabetes mellitus (T2DM), to explore the effect of different hypoglycemic drugs on the level of plasma leptin in patients with both T2DM and CHD, in the hope of discovering the potential methods in preventing the T2DM to develop to the CHD later and treating the patients with both T2DM and CHD.Methods:30 controls (group A), 60 T2DM (group B) and 60 T2DM with CHD (group C) were recruited according to the inclusion criteria. The clinical data including age, body mass index (BMI), waist to hip ratio (WHR), mean artery pressure (MAP), lipoproteins, fasting plasma glucose (FPG), fasting insulin (FINS), high-sensitivity C-reactive protein (HsCRP) and glycosylated hemoglobin (HbA1c)were collected for analysis. Subjects in group C were randomly grouped by sex and then each was further divided into the same insulin group, insulin plus rosiglitazone group and metformin group randomly. The levels of plasma leptin in group A, B and C ware compared, the correlations of this indicator among the three groups ware also investigated. At last, the plasma leptin was detected before and after the various hypoglycemic treatment respectively to discuss the effects of those interventions mentioned above. Fasting plasma leptin was detected by enzyme-linked immunosorbent assay, insulin resistance were evaluated with the insulin resistance index(IRI). All data were analyzed by SPSS13.0 software.Results:Fasting plasma leptin in group C were significantly higher than that of the other two groups (P <0.05), but no significant difference was found between group A and group B (P >0.05). All parameters in each group were evaluated with the pearson correlation coefficient analysis, plasma leptin was positively correlated with BMI, WHR, FINS and IR in group A, with the correlation coefficients of 0.451(P =0.012), 0.398(P =0.029), 0.363(P =0.049)and 0.558(P =0.001)respectively, and triglyceride (TG), very low density lipoprotein cholesterol(VLDLC), HsCRP in group B, with the correlation coefficients of 0.279(P =0.031), 0.281(P =0.030)and 0.359(P =0.005)respectively, and total cholesterol(TCH), low density lipoprotein cholesterol (LDLC ), HsCRP in group C, with the correlation coefficients of 0.257(P =0.048), 0.262(P =0.043)and 0.361(P =0.005)respectively . Logistic regression analysis revealed that leptin was an independent risk factor of T2DM with CHD. FPG levels were well controlled by insulin, insulin plus rosiglitazone and metformin respectively in group C, at the same time, the level of plasma leptin in insulin plus rosiglitazone group and metformin group was reduced obviously (P <0.05).Conclusions:Leptin, as an independent risk factor of T2DM patients with CHD, was involved in the T2DM complicated by CHD and closely relate to the changes of the level of lipoproteins and HsCRP. The level of plasma leptin could be reduced under both rosiglitazone and metformin treatment in T2DM patients complicated by CHD, and the risk of developing CHD in patients with T2DM also could be reduced.