Type 2 diabetes mellitus is a polygenic metabolic disorder resulting from oxidative stress, the root cause of insulin resistance, β-cell dysfunction and impaired glucose tolerance. The aim of this study was to investigate the role of oxidative stress–related genes ALOX5, ALOX5AP, GPX1, GPX3 and MPO in type 2 diabetes mellitus susceptibility in the Chinese Han population.

A total of 396 type 2 diabetes mellitus patients and 678 controls were recruited. The ALOX5 rs10900213, ALOX5AP rs4293222, GPX1 rs1050450, GPX3 rs3828599 and MPO rs2107545 gene polymorphisms were genotyped.

We found one single-nucleotide polymorphism in the MPO gene was associated with type 2 diabetes mellitus susceptibility [rs2107545: odds ratio = 1.563 (1.166–2.096); p = 0.003], after adjusting for covariates. Furthermore, we also considered the likely complexity of effects of genetic and conventional risk factors in type 2 diabetes mellitus–related vascular complications, such as carotid plaques. Our analysis revealed that the GPX1 rs1050450 and MPO rs2107545 were significantly associated with increased risk of carotid plaques in type 2 diabetes mellitus patients.

Our study presents novel evidence for main effects of MPO gene on type 2 diabetes mellitus susceptibility. Furthermore, our study supported the association between variants of oxidative stress–related genes (GPX1 and MPO) and carotid plaques in type 2 diabetes mellitus patients, which indicated a modulation of type 2 diabetes mellitus–related vascular complication susceptibility by genetic predisposition.