The change of oxidative stress products in diabetes mellitus and diabetic retinopathy.
OBJECTIVE
Enhanced oxidative stress contributes to the pathogenesis of diabetic retinopathy. The aim of this study is to detect oxidative stress parameters in type 2 diabetes mellitus with or without retinopathy and to investigate the relationship between oxidative stress and patients with type 2 diabetic retinopathy.


METHODS
Oxidative stress parameters included malondialdehyde (MDA), conjugated diene (CD), advanced oxidation protein products (AOPP), protein carbonyl and 8-hydroxydeoxyguanosin (8-OHdG) in serum measured in 33 patients with diabetes mellitus without complications, 27 diabetes mellitus retinopathy and 32 normal control subjects, respectively.


RESULTS
The concentrations of MDA and CD in type 2 diabetes mellitus (DM) were significantly higher than those of the control subjects (p<0.01). The concentration of MDA and CD in patients with retinopathy was significantly elevated in comparison with patients with diabetes without retinopathy (p<0.05). There was a significant increase in serum 8-OHdG in patients with diabetes compared with normal subjects (p<0.01), and serum 8-OHdG was much higher in diabetes mellitus retinopathy than that in patients with diabetes without retinopathy (p<0.05). This was significantly higher in serum AOPP and protein carbonyl in type 2 DM compared with normal subjects (p<0.01). Moreover, diabetes mellitus retinopathy patients had significantly higher AOPP and protein carbonyl compared with patients with diabetes without retinopathy (p<0.05).


CONCLUSIONS
These results indicate that there were severe lipid peroxidation, protein oxidation, and oxidative DNA damage in diabetes. The augmented oxidative stress in diabetes may be speculated to contribute to the pathogenesis of diabetes mellitus. Oxidative stress is an important risk factor in the development of diabetic retinopathy. The levels and the types of serum oxidative stress by-products will be in favour of predicting the amount of retinopathy.
Pan
Hong-Zhi
HZ
First Affiliated Hospital of the Harbin Medical University, No. 23 Youzheng Street, Nangang District, Harbin, Heilongjiang, 150001, China; dongchang1969@163.com.
Zhang
Hong
H
Chang
Dong
D
Li
Hui
H
Sui
Hong
H
D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000378:metabolism; D004249:DNA Damage; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress
D001798:Blood Proteins; D008315:Malondialdehyde