TCF7L2 rs7903146 C>T gene polymorphism is not associated with hypoglycemia in sulfonylurea-treated type 2 diabetic patients

Abstract

Abstract Objectives Hypoglycemia is the most common adverse effect of sulfonylureas (SUs) and a major concern when using these drugs. Transcription factor 7-like 2 (TCF7L2) rs7903146 C>T polymorphism is an established and well characterized genetic marker of type 2 diabetes (T2DM) risk. The aim of the present study was to analyze the potential association of TCF7L2 rs7903146 C>T polymorphism with SU-induced hypoglycemia in a well characterized cohort of SU-treated patients previously genotyped for cytochrome P450 2C9 (CYP2C9) and P450 oxidoreductase (POR). Methods The study group consisted of 176 SU-treated T2DM patients of whom 92 had experienced at least one drug-associated hypoglycemic event. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for TCF7L2 rs7903146 genotyping. Results TCF7L2 rs7903146 C>T genotype and allele frequency did not differ between cases and controls (p=0.745 and 0.671, respectively). In logistic regression analysis adjusted for other factors affecting hypoglycemia, including CYP2C9 and POR genotypes, TCF7L2 rs7903146 C>T polymorphism did not increase the risk of hypoglycemia (OR=1.238, 95% C.I.=0.750–2.044, p=0.405). Conclusions TCF7L2 rs7903146 C>T polymorphism is not associated with SU-induced hypoglycemia. Identifying additional gene polymorphisms associated with SU-induced hypoglycemia is crucial for improving T2DM patient therapy with SUs.