Polymorphism − 116C/G of the human X box binding protein 1 gene is associated with risk of type 2 diabetes in a Chinese Han population

•The − 116GG genotype and − 116G allele of XBP1 were more frequent in T2D subjects compared with control subjects.•T2D subjects with 116GG genotype of XBP1 had higher fasting plasma glucose, fasting insulin, HbA1c and worse HOMA-IR.

Evidence has been obtained showing that endoplasmic reticulum (ER) stress is closely associated with the development of type 2 diabetes (T2D) and that the human X box binding protein 1 (XBP1) is an important transcription factor involved in the development of ER stress. The study aimed to analyze the potential association between polymorphism − 116C/G of XBP1 and the risk of T2D. The association between XBP1 polymorphism − 116C/G and T2D risk was assessed among 1058 consecutive unrelated subjects, including 523 T2D patients and 535 healthy controls, in a case control study. The − 116GG genotype and − 116G allele were more frequent in T2D subjects compared with control subjects by statistical analysis, showing that the − 116GG homozygote polymorphism of XBP1 might lead to increased susceptibility to T2D in a Chinese Han population. T2D subjects with the − 116GG genotype had higher fasting plasma glucose levels, fasting insulin levels, and HbA1c and worse HOMA-IR than the T2D subjects with − 116CG and − 116CC genotypes (P < 0.0001). The study supports a role for − 116C/G polymorphism of the XBP1 promoter in the pathogenesis of T2D in a Chinese Han population, and more studies are needed to further evaluate our results.