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.