Basal serum nitric oxide levels in patients with type 2 diabetes mellitus and different stages of retinopathy.
OBJECTIVE
To compare the basal serum levels of nitric oxide (NO) in patients with type 2 diabetes mellitus and different stages of diabetic retinopathy (DR) with the levels in nondiabetic control subjects.


METHODS
The 39 patients with type 2 diabetes included in this study were divided by stage of DR into 3 groups: group A, those without DR; group B, those with background/preproliferative DR; and group C, those with proliferative DR. Eleven nondiabetic subjects made up the control group (group D). The NO concentration was determined indirectly by measuring the serum level of nitrite (NO2-) plus nitrate (NO3-) (NOx = NO2- plus NO3-) using a spectrophotometric method based on the Griess reaction.


RESULTS
The patients with type 2 diabetes had significantly higher levels of serum NOx than the nondiabetic controls (p = 0.0001). In addition, the levels in the patients with proliferative DR were significantly higher (p = 0.002) than the levels in the patients with nonproliferative or no DR.


CONCLUSIONS
Our study demonstrated both elevated levels of serum NOx in diabetic patients as compared with nondiabetic controls and a relationship between NOx and DR severity. Hence, abnormal NO metabolism may have a role in the pathogenesis of DR.
Ozden
Serap
S
Department of Ophthalmology, Pamukkale University School of Medicine, Denizli, Turkey. serapesma@yahoo.com
Tatlipinar
Sinan
S
Biçer
Nilgün
N
Yaylali
Volkan
V
Yildirim
Cem
C
Ozbay
Davut
D
Güner
Gill
G
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications*; D003930:Diabetic Retinopathy / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000097:blood*; D009573:Nitrites / Q000097:blood
D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide