Objective: To determine the changes of advanced oxidation protein products (AOPP) in diabetic nephropathy (DN) patients, as well as its relationship with superoxide dismutase (SOD), glutathione peroxidase (GPx) and neopterin (NPT).
Methods: By the concentration of urinary albumin excretion rate (UAER) and creatinine (Cr), 85 diabetes mellitus (DM) patients were divided into 4 groups as non-DN group (DM), early-staged DN group (DN3), significant DN group (DN4) and end-staged DN group (DN5). The concentration of the serum AOPP was measured by ameliorated method introduced by Wikto-Sarsat, while SOD by Xanthine oxidase test, GPx by [5,5'Dithio-bis (2-Nitrobenzoic aicd) ] (DTNB) reaction test and NPT by ELISA.
Results: AOPP in Group DN5 [(117.8 +/- 64.8) [micromol/L] and Group DN4 [ (80.0 +/- 23.0) micromol/L] were significantly higher than those in Group DM [(58.2 +/- 17.7) micromol/L]. There was no significant difference of AOPP between Group DN3 [(72.7 +/-17.2) micromol/L] and Group DM. Serum AOPP negatively correlated with SOD and GPx (r = -0.217 and -0.374 respectively, P < 0.05), while positively correlated with NPT (r = 0.499, P < 0.01).
Conclusion: DN patient has enhanced protein oxidation than DM patient, which is related to oxidative stress and chronic inflammation in DN.