Protein oxidation markers in women with and without gestational diabetes mellitus: A possible relation with paraoxonase activity

Abstract Aims To clarify the levels of protein oxidation markers such as protein carbonyl (PCO), protein hydroperoxides (P-OOH), advanced oxidation protein products (AOPP) and nitrotyrosine (NT), as well as antioxidative enzymes such as paraoxonase (PON-1) in women with and without gestational diabetes mellitus (GDM). Methods The study was conducted on 23 women with GDM and 22 women without GDM. The levels of the P-OOH, AOPP, and PON-1 were determined by colorimetric methods; whereas NT and PCO levels were measured by ELISA. Results The concentrations of protein oxidation markers were significantly increased and PON1 activity was significantly decreased in GDM group compared to those of normal pregnant women. The control group showed a significant negative correlation between PON-1 and PCO ( r = −0.451, p = 0.027); whereas in GDM group, there was a significant positive correlation between P-OOH and HbA1c ( r = 0.89, p = 0.001). There was no significant correlation between AOPP, PON-1, P-OOH, PCO, and HbA1c in either group. Conclusions There is evidence of a possible association between protein oxidation and decreased PON1 activity in GDM. The increase in protein oxidation parameters in the GDM group leading to decreased PON1 activity might, we think, create a predisposition for clinical complications in GDM group.