Research Of Pancreatic Endocrine And Exocrine Function In Type 3c Diabetes

Objective: This study aiming to evaluate the damage of pancreatic endocrine and exocrine function in patients with type 3c diabetes mellitus(T3cDM)caused by pancreatic exocrine disease,and to explore the interrelationship between endocrine and exocrine function.Compare the changes of pancreatic endocrine and exocrine related indicators by mixed meal test,and provide a basis for further clinical identification of T3 cDM and T2 DM.Method:(1)The subjects were recruited through follow-up of hospitalized patients and social recruitment,and were divided into three groups: 1.T3 cDM after chronic pancreatitis(CP),2.type 2 diabetes mellitus(T2DM),3.healthy controls,10 subjects in each group.(2)After signing the informed consent forms,the blood samples were collected in the early morning the next day after fasting for at least 10 h to measure insulin(INS),C-peptide(C-P),glucagon(GCG),pancreatic polypeptide(PP),glucagon-like peptide-1(GLP-1),and Gastric inhibitory peptides(GIP).(3)All participants were given 12 oz.of BOOST? drink.Blood samples were collected at 15,30,60 and 120 min following a mixed meal to measure INS,C-P,GCG,PP,GLP-1 and GIP.(4)According to whether CP patients had undergone partial pancreatectomy,T3 cDM were divided into two subgroups: operation and non-operation groups.Increases in hormone levels from baseline were compared among all groups.Results:(1)BMI of T3 cDM patients were lower than that of T2DM(P<0.05).The proportion of smokers in T2 DM and T3 cDM were higher(P=0.040).Compared to T2 DM,individuals in T3 cDM had lower FBG,HbA1 c and HOMA-IS,and higher HOMA-IR,HOMA-?(P>0.05).There was no significant difference in AMY levels among three groups.The Vitamin D level was the lowest in T3 cDM compared to controls,and T2 DM took second place(P<0.001).(2)There was no statistical difference in PP response to mixed meals in three groups.T3 cDM and T2 DM had higher levels of fasting and postprandial CP and INS.The GCG level in T3 cDM and T2 DM were higher than those of healthy controls,and reached the peak in 15-30 min after meal.The responses of GIP and GLP-1 in T3 cDM were higher than T2 DM,but showed no statistical difference.(3)In T3 cDM subgroup after pancreatic operation,the levels of PP,C-P,INS,GCG,and GIP was significantly lower than those without operation,while the reaction of GLP-1 was reserved.In non-operation group,the response of C-P,INS,PP and GIP were higher compared to T2 DM.Conclusion:(1)The C-P and INS responses were weakened after stimulation in T3 cDM group,and the PP and GCG responses were enhanced.GIP and GLP-1 retained normal responses,suggesting that patients with T3 cDM have impaired pancreatic exocrine and endocrine function insufficiency.(2)The responses of C-P,INS,GCG,PP and GIP to mixed meal stimulation were significantly weakened in the T3 cDM group.The PP response was completely lost,and the response of GLP-1 was still retained.The C-P,INS,PP,and GIP responses in the non-surgical group was higher than those in the T2 DM group.The mixed meal test has reference value for the identification of T3 cDM and T2 DM.