The role of Leu260Phe polymorphism of the receptor gene to GLP-1 incretin in the pathogenesis of diabetes type 2 diabetes with obesity

BACKGROUND: Glucagon-like peptide-1 (GLP-1) stimulates the proliferation of β-cells, enhances their resistance to apoptosis and increases glucose-dependent insulin secretion.

AIMS: Study of the relationship of Leu260Phe polymorphism (rs1042044) of the GLP-1R gene with postprandial hormone production (C-peptide, insulin, ghrelin, GLP-1) in obese patients with type 2 diabetes.

MATERIALS AND METHODS: A total of 174 patients, 82 patients with obesity with type 2 diabetes (BMI=40.4±14.3 kg/m²)and 92 conditionally healthy donors (BMI=22.6±2.7 kg/m²) were studied. The material for the study was venous blood taken on an empty stomach and 60 minutes after the test breakfast. Genotyping was performed by PCR using the sets for determining polymorphism (rs1042044) of the GLP-1R gene (Sintol) and the amplificator (CFX96 BioRad, USA). Plasma hormone levels were evaluated by flow fluorimetry (Bio-PlexProteinAssaySystem, Bio-Rad, USA) using commercial test systems (Bio-PlexProHumanDiabetes 10-Plex Assay, Bio-Rad, USA). Statistical analysis and graphs were obtained at R Statistical Software.

RESULTS: A violation of postprandial production of GLP-1 and ghrelin after a test breakfast in obese patients with type 2 diabetes was found. A postprandial increase in C-peptide levels of 3.25[1.83;4.16] ng/ml and insulin 3048 [1978;4972] ng/ml in carriers of the CC genotype compared with carriers of the CA genotype in the group of patients with obesity with type 2 diabetes type In carriers of the CA genotype, there was a decrease in the C-peptide level of 2.21 [1.8;2.49] ng/ml and insulin 1462 [1146; 2304] ng/ml with a constant concentration of GLP-1. The postprandial level of ghrelin in carriers of the CA genotype of the Leu260Phe polymorphism increased to 118[96.1;157] ng/ml compared to carriers of the AA 98 genotype [86; 109] ng/ml.

CONCLUSION: The presence of the CC genotype of the Leu260Phe polymorphism of the GLP-1 receptor gene is associated with an increase in postprandial plasma levels of C-peptide and insulin in obese patients with type 2 diabetes, and the CA genotype with a decrease in these indicators and an increase in ghrelin content.

type 2 diabetes, obesity, polymorphism, GLP-1R, insulin, ghrelin

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