Age-dependent systemic DNA damage in early Type 2 Diabetes mellitus

Oxidative stress, capable of eliciting damage to various biomolecules including DNA, is a recognized component of diabetes mellitus and its complications. Metabolic syndrome  (MetS) is associated with the development of type 2 diabetes mellitus  (T2DM), as well as other unfavorable outcomes. The aim of this study was to elucidate the role of oxidative stress in the development of T2DM, by investigating association of oxidative DNA damage with metabolic parameters in subjects with MetS and early T2DM. Selected anthropometric and biochemical parameters of MetS, inflammation and oxidative DNA damage: body mass index  (BMI), fatty liver index  (FLI), waist circumference  (WC), total cholesterol, HDL  and LDL-cholesterol, GGT, uric acid, total leukocyte/neutrophil count,  and urinary 8-oxo-deoxyguanosine  (u-8-oxodG) were assessed in male subjects with MetS and both younger  (≤55 years) and older  (>55 years) subjects with T2DM of short duration without complications. BMI, FLI, WC, total and LDL-cholesterol and  uric acid were higher, while the u-8-oxodG was lower in MetS group, when compared to older T2DM subjects. None of these parameters were different neither between MetS and younger T2DM, nor between two sub-groups of subjects with T2DM. Values of CRP, HDL-cholesterol, triglycerides, GGT, leukocytes and neutrophils were not different between all examined groups of subjects. Age-dependent increase in u-8-oxodG suggests that aging process, rather than metabolic disturbances or diabetes per se plays a pivotal role in development of oxidative DNA-damage in T2DM. Oxidative DNA damage cannot serve as an universal early marker of T2DM.