Alterations in antioxidant capacity, lipid peroxidation, and nitrite levels in type 2 diabetes

Background: this case-control study delves into oxidative and antioxidant markers, including Total Antioxidant Capacity (TAC), lipid peroxidation, and nitrites, alongside glucose levels in individuals with hyperglycemia due to type 2 diabetes mellitus (T2DM) in comparison to their healthy counterparts. Furthermore, the study explores the impact of glucose on these variables. Methods: twenty patients diagnosed with T2DM and hyperglycemia were included, along with a control group of 20 healthy subjects (Control Group – CG). Glucose levels, as well as oxidative markers (malondialdehyde and nitrites) and antioxidants, were assessed in the blood plasma of each participant. To ascertain statistically significant differences between the studied variables across groups, Student t-test or Mann–Whitney tests were employed. Pearson’s Linear Correlation test was utilized to evaluate associations between the variables. Results: glucose and TAC levels exhibited significant elevation in the T2DM group compared to the CG. In T2DM patients, malondialdehyde and nitrites demonstrated reduced levels (1.83±0.84 µM/L and 29.5±16.6 µmol/L, respectively) in contrast to the CG (4.00±1.11 µM/L and 82.9±29.2 µmol/L, respectively), with both parameters showing a robust positive correlation (p = 0.0002). Conclusions: individuals with diabetes manifest alterations in the redox state, characterized by diminished lipid peroxidation and nitrite levels, suggesting disruptions in the constitutive pathway for nitric oxide production. This underscores the intricate interplay between oxidative stress, antioxidants, and glucose metabolism.