Oxidative stress and nitric oxide related parameters in type II diabetes mellitus: effects of glycemic control.
OBJECTIVE
The aim of this study is to investigate the status of oxidative stress and nitric oxide related parameters in type II diabetes mellitus (DM) patients in which heart disease, atherosclerosis, retinopathy, and nephropathy commonly occur, and also to determine the effect of glycemic control on these parameters.


METHODS
Erythrocyte copper zinc-superoxide dismutase (CuZn-SOD), erythrocyte and plasma selenium dependent glutathione peroxidase (Se-GPx), erythrocyte catalase (CAT) activities, erythrocyte and plasma thiobarbituric acid reactive substances (TBARS) levels; nitrite/nitrate (NO(2)(-)/NO(3)(-)), cyclic guanosine monophosphate (cGMP) and nitrotyrosine levels in plasma of type II DM patients were measured.


RESULTS
Erythrocyte CuZn-SOD activities in type II DM were significantly higher than those of the control subjects (p < 0.05). TBARS levels in type II DM were significantly higher than the control subjects (p < 0.001). Plasma NO(2)(-)/NO(3)(-) levels in type II DM patients both during poor glycemic control and after three months of oral antidiabetic treatment were significantly higher than those of the control subjects (p < 0.001). Plasma cGMP levels in type II DM patients during poor glycemic control were significantly lower than those of control subjects (p < 0.001).


CONCLUSIONS
These results indicate that oxidative status and nitric oxide metabolism are affected in type II DM patients. We found high CuZn-SOD activity in type II DM patients. This increased activity could not protect the patients against the reactive oxygen species (ROS), since lipid peroxidation (defined by erythrocyte and plasma TBARS levels) still occurs in DM patients. After the therapy with oral antidiabetic agents for three months, erythrocyte SE-GPx and CAT activities were found to be decreased below the control values. Our results suggested that the low cGMP levels in the study may be a good marker of endothelium dysfunction in DM.
Aydin
A
A
Gülhane Military Medical Academy, Department of Toxicology, 06018, Etlik, Ankara, Turkey. aaydin@obs.gata.edu.tr
Orhan
H
H
Sayal
A
A
Ozata
M
M
Sahin
G
G
Işimer
A
A
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002374:Catalase / Q000097:blood; D006152:Cyclic GMP / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000097:blood; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D012643:Selenium / Q000378:metabolism; D013482:Superoxide Dismutase / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood
D007004:Hypoglycemic Agents; D009566:Nitrates; D009573:Nitrites; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D006152:Cyclic GMP; D012643:Selenium