Introduction: Diabetes mellitus is an important and rapidly increasing problem in public health. It associates with endothelial dysfunction and increased endothelial permeability, which may lead to severe cardiovascular events.
Objectives: We aimed to evaluate the relationship between polymorphisms in the cytochrome b-245 alpha chain (CYBA) gene encoding p22phox, a key subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, with endothelial function, atherosclerosis and systemic oxidative stress in type 2 diabetes mellitus (T2DM).
Patients and methods: Intima-media thickness (IMT), flow- and nitroglycerin-mediated dilatation (FMD and NMD) were measured in 182 patients with T2DM. Assessment of plasma levels of von Willebrand factor (vWF) and malondialdehyde (MDA) levels as well as genotyping of coding sequence C242T (rs4673) and promoter region A-930G (rs9932581) polymorphisms of CYBA were performed using standardized protocols.
Results: We observed a significant association of the impaired endothelial function, as measured by FMD, with the C allele of C242T, but not with the A-930G polymorphism. Functional relationship of the C242T polymorphism with endothelial dysfunction remained significant following a multivariable adjustment for major risk factors for atherosclerosis. Mean IMT, NMD, concentrations of MDA or vWF were not related to the specific genotypes of the investigated polymorphisms.
Conclusions: C242T, but not A-930G, polymorphism of CYBA significantly affects endothelial function in T2DM. Thus, it might be a useful marker of endothelial dysfunction in T2DM patients.