Effects Of Plasma TG And LDL Levels On The Islet ? And ? Cell Function In Type 2 Diabetes Patients

Objective The pathogenesis of type 2 diabetes mellitus is focused on insulin resistance and beta-cell dysfunction.Recently,the effectes of glucagon to T2 DM has become prominent medical concerns.Insulin and glucagon participate in glucose homeostasis.Studies demonstrate that hyperlipidemia not only cause insulin resistance,but also induced glucagon secretion increased,which contributing to glucose metabolism.We studied the different levels of plasma TG and LDL,to research the effects of them on the function of the islet ? and ? cell.Methods 328 T2 MD patients, fast glucose?insulin?glucagon?Hb A1c?TC?TG?LDL?HDL were obtained. According to the level of TG and LDL,these subjects were divided into three groups. According to the plasma TG,group T1: TG<1.70mmol/L;group T2:TG 1.70~2.25 mmol/L;group T3:TG?2.26 mmol/L. According to the plasma LDL,group L1: LDL<2.60 mmol/L;group L2:LDL 2.60~3.10 mmol/L;group L3:LDL>3.10 mmol/L.A 75 g Oral glucose tolerance test( OGTT) was administered and insulin release test and glucagon release test were taken to obtain the differences of glucagon level, glucagon/insulin, early insulin secretion index( I30/ G30) and Insulin resistance index,etc among the three groups,and correlation analysis was made between glucagon and other indicators.Results(1) Person correlation analysis indicated that glucagon was negatively correlated with HOMA-??AUCI? HDL??I30/?G30?ISI,and positively correlated with LDL?TG?BMI?Hb A1c?HOMA-IR?FPG,no correlated with TC?SDP?DBP.(2) Compared with TG<1.7mmol/L group,glucagon levels in TG?2.26 mmol/L group at fasting and postprandial were significantly increased at each time point except 60 min; area under curve of glucagon was significantly elevated; glucagon /insulin was significantly increased on fasting and postprandial;and HOMA-?, I30/ G30, AUCI,ISI were significantly decreased, On the contrary, HOMA-IR was significantly increased. Comparison between TG1.7-2.25mmol/L group and TG<1.7mmol/L group, glucagon level was significantly increased at fasting and postprandial 30min; area under curve of glucagon was significantly elevated; glucagon /insulin was increased, but had no statistical significance;and I30/ G30, AUCI,ISI were significantly decreased.(3) Compared with group of LDL<2.60, glucagon level in LDL>3.10 group were significantly increased at fasting and postprandial expect 120min; area under curve of glucagon was significantly elevated; glucagon /insulin was significantly increased on whether fasting or postprandial; HOMA-?? I30/ G30 and ISI were significantly induced, HOMA-IR was significantly increased, AUCI had no statistical significance. Comparison between LDL2.60~3.10mmol/L group and LDL<2.60mmol/L group,only fasting glucagon was significantly increased;and I30/ G30,ISI were induced significantly.Conclusions(1)The plasma glucagon level was negatively correlated with HOMA-??AUCI??I30/?G30?ISI,and positively correlated with LDL?TG?HOMA-IR and FPG,no correlated with TC?SDP?DBP.(2)The plasma glucagon concentration and glucagon/insulin have the trend of rising along with the rising of plasma TG level,in contrast,the function of beta cell was decreased. Administering plasma TG concentration may contribute to the decrease of glucagon in T2 MD patients,help to restore the functions of islet ? cell and do better to glycemic control.(3) Keep the plasma level of LDL under the control of 2.60mmol/L would contribute to induce glucagon of T2 MD patients, inhibit the secretion of pancreatic islet alpha cells and improve the function of islet beta cells,and finally reduce hyperglycaemia in patients with type 2 diabetes.