SNP Study of DPP-4 and GLP-1R in Chinese People (Including Diabetes Patients)

Diabetes Mellitus Clinical Trial

Official title: Study on Polymorphism of DPP-4 and GLP-1R Genes in Chinese Population and Its Empirical Study on Treatment of Diabetes

Status Completed

Clinical Trial Summary

Incretin-based therapy is currently one of the most popular diabetes treatment approaches. However, differences of response ware found in previous studies. We hypothesis that SNPs of DPP-4, GLP-1 and GLP-1R genes may play crucial roles in the response differences. Therefore, this study aims to investigate the correlation of incretin-related gene polymorphism and individual differences in the response of DPP-4 inhibators (take Sitagliptin as an example). In addition, The distribution differences of the SNPs in diabetics and non-diabetics are evaluated to study the relationships between the SNPs and diabetes onsets.

Clinical Trial Description

Single Nucleotide Polymorphism (SNP) plays an important role in the differences of clinical manifestations and drug responses of diseases. The vast majority of SNP sites are located in the non-coding region of the gene (about 95%), which is called SNP(non-coding SNP (ncSNP), while the other part of SNP is located in the coding region of the gene, which is called coding SNP (cSNP). Furthermore, cSNP can be divided into two categories: SNP that does not change the encoded amino acid sequence is called synonymous SNP(synonymous SNP, SSNP); SNP that changes amino acid sequence is called SNP(non-synonymous SNP (NSNP). Although not involved in coding amino acid, some ncSNPs may also affect the regulation of protein expression. Therefore, it is of great significance to study the effects of NC SNP and cSNP on the occurrence and development of diseases and drugs.

DPP-4 enzyme inhibitor is combined with DPP-4 enzyme in human body to reduce hydrolysis of active GLP-1, thus increasing the level of endogenous active GLP-1. Active GLP-1 combines with its receptor GLP-1R to promote insulin release and inhibit glucagon release in hyperglycemia state, and produces opposite effect in hypoglycemia state.

Based on the above principles, we speculate that SNP of genes that may affect the hypoglycemic effect of DPP-4 enzyme inhibitor are:

1. SNP of DPP-4 enzyme gene. SNP of DPP-4 enzyme gene may affect the enzyme activity and/or protein expression level of DPP-4. Assuming that the effect of DPP-4 enzyme inhibitor is sufficient, patients with higher DPP-4 enzyme activity are more sensitive to DPP-4 enzyme inhibitor drugs; However, for patients with low DPP-4 enzyme activity, DPP-4 enzyme inhibitor drugs cannot play a stronger role in lowering blood sugar.

2. SNP of GLP-1 gene. SNP of GLP-1 gene may affect activity or expression level of GLP-1. Patients with high GLP-1 level are more sensitive to DPP-4 enzyme inhibitor drugs.

3. SNP of GLP-1R gene. SNP of GLP-1R gene may affect activity or expression level of GLP-1R. Patients with high GLP-1R level are also more susceptible to DPP-4 enzyme inhibitor drugs.

However, studies on the hypoglycemic effect of DPP-4, GLP-1 and their receptors on DPP-4 enzyme inhibitors in the treatment of T2DM are rare, which is not conducive to the evaluation of individualized treatment of such drugs. Therefore, this chapter intends to select SNP sites with high mutation frequencies of DPP-4, GLP-1 and GLP-1R genes to study the mutation frequencies of these SNPs in diabetic patients and non-diabetic patients and their effects on DPP-4 enzyme inhibitor sitagliptin's hypoglycemic effect on T2DM patients. ;

Related Conditions & MeSH terms

• Diabetes Mellitus

• NCT number: NCT03108521
• Study type: Interventional
• Source: Sichuan Provincial People's Hospital
• Status: Completed
• Phase: Phase 4
• Start date: April 21, 2016
• Completion date: October 8, 2018