Study On The Correlation Between Fasting C-peptide Level And Diabetic Microvascular Complications In Type 2 Diabetes Patients

Background:Diabetes mellitus is a serious chronic metabolic disease characterized by hyperglycemia.The prevalence of diabetes is increasing all over the world and has become a global burden.Long-term and chronic high blood glucose level can lead to dysfunction of endothelial cells,affect hemodynamics and tissue metabolic disorders,and cause chronic damage of large and small blood vessels and various complications.Diabetic microvascular complications are special complications of diabetes,including diabetic retinopathy(DR),diabetic nephropathy(DN)and diabetic peripheral neuropathy(DPN).The pathogenesis is complex.C-peptide is a peptide hormone containing 31 amino acids.It not only reflects the function of pancreatic islet cells,but also has the potential of anti-inflammation,anti-apoptosis,anti-oxidation and vascular protection,which can resist the low degree of inflammation secondary to the formation of high glucose environment,and is beneficial to the microvascular diseases of type 1diabetes patients.However,fasting C-peptide(FCP)levels in type 2 diabetic microvascular complications are still controversial,FCP levels need to be studied further relation with microvascular complications in type 2 diabetes,guide the clinical work.Objective:To analyze the correlation between fasting C-peptide level and diabetic microvascular complications in patients with type 2 diabetes,and to discuss its clinical significance.Methods:A retrospective analysis was performed on 829 patients with type 2diabetes who were hospitalized in the Department of Endocrinology,the first hospital of Jilin University from January 2019 to January 2020 to collect their clinical data.The included objects were divided into DR group and Non-DR group,DN group and Non-DN group,DPN group and Non-DPN group according to whether there was DR,DN and DPN.Statistical software SPSS21.0 was used to compare the differences among the clinical data of the subjects in each group,and the groups were divided into Ql,Q2,Q3 and Q4according to the quartile of FCP.The relationships between FCP and DR,DN and DPN were further analyzed,and the risk factors of diabetic microvascular complications were analyzed by Logistic regression.At the same time,the correlation between FCP level and laboratory indexes was discussed.Results:(1)Compared with the Non-DR group,the diabetes course in the DR group was longer and FCP,high density lipoprotein cholesterol and low density lipoprotein cholesterol were lower,with statistically significant differences(P<0.05).Compared with the Non-DN group,the duration of diabetes in the DN group was longer and the systolic blood pressure was higher,and the difference was statistically significant(P<0.05).Compared with the Non-DPN group,the duration of diabetes in the DPN group was longer,the systolic blood pressure was higher,and the triglyceride was lower,with statistically significant differences(P<0.05).(2)At different FCP levels,the prevalence of DR in groups Q1,Q2,Q3and Q4 were 28.16%,25.37%,20.47%,17.39%.The difference in prevalence of DR in the four groups was statistically significant(X~2=8.219,P<0.05).With the increase of FCP level,the prevalence of DR showed a decreasing trend.Each group compared between groups,The prevalence of DR in Q4group was significantly lower than that in Q1 group and Q2 group,and the difference was statistically significant(P<0.05).Further comparison of the percentage of DR patients in Q1,Q2,Q3 and Q4 groups in the total number of DR patients was 30.69%,26.98%,23.28%and 19.05%,respectively.At different FCP levels,the prevalence of DN in groups Q1,Q2,Q3 and Q4 were14.08%,12.44%,8.37%and 16.91%,respectively.The difference in prevalence of DN in the four groups was not statistically significant(X~2=7.172,P>0.05).At different FCP levels,the prevalence of DPN in groups Q1,Q2,Q3and Q4 was 16.50%,15.92%,17.67%and 13.53%,respectively.The difference of DPN prevalence in the four groups was not statistically significant(X~2=1.433,P>0.05).(3)Logistic regression analysis showed that FCP and high density lipoprotein cholesterol were independent protective factors for DR,and the course of diabetes was an independent risk factor.(4)Correlation analysis showed that FCP was positively correlated with triglycerides(P<0.05),and negatively correlated with high density lipoprotein cholesterol and glycosylated hemoglobin(P<0.05).Conclusion:(1)FCP level is negatively correlated with type 2 diabetic retinopathy,and higher C-peptide level is a protective factor.C-peptide may be a new target for the treatment of type 2 diabetic retinopathy.(2)There was no significant correlation between FCP level and type 2diabetic nephropathy.(3)There was no significant correlation between FCP level and type 2diabetic peripheral neuropathy.