Erythrocyte membrane anionic content and urinary glycosaminoglycan excretion in type 1 diabetes: association with retinopathy.
BACKGROUND
In diabetic nephropathy, increased excretion of glycosaminoglycans and loss of basement membrane anionic charge had been documented to be related with diabetic microalbumuniria. There was no study that studied those two factors in clinical settings with a degree of diabetic retinopathy in type 1 diabetics.


METHODS
Forty subjects (aged 27.3 +/- 6.3) with type 1 diabetes with different levels of diabetic retinopathy and 30 healthy subjects (aged 29.52 +/- 8.7) were included in the study. Subjects were first divided as patients without (R0) and with (R1) retinopathy. They then were further divided into two subgroups with the help of fundus angiography as diabetic lesions demonstrable with fluorescein angiography (R1A) and early diabetic retinopathy lesions on fundus examination (R1B). Erythrocyte anionic charge (EAC) was determined by the binding of cationic dye, alcian blue, and urinary glycosaminoglycan excretion and (UGAG) was determined spectrophotometrically.


RESULTS
UGAG was increased (35.74 +/- 14.01 vs 21.25 +/- 6.19 micro g/mL, 95% confidence intervals [CI], 9.01-19.96, p = 0.02) and EAC (62.14 +/- 27.17 vs. 158.53 +/- 36.98 ng alcian blue 106 per 106 RBC, 95% [CI] -111.68-81.10, p = 0.0001) was decreased significantly in diabetic patients with respect to controls. As the grade of diabetic retinopathy increased, UGAG increased and EAC decreased within subgroups of diabetic patients (p < 0.005). UGAG positively correlated (r = 0.36 and p = 0.03) and EAC negatively (r = -0.695, p = 0.0001) correlated with diabetes duration. EAC and UGAG negatively correlated (r = -0.58 and p = 0.0001) with each other in type 1 diabetics. EAC (p = 0.007) and diabetes duration (p = 0.001) were found to be the two significant factors to have diabetic retinopathy in diabetics with logistic regression analysis.


CONCLUSIONS
Although we need more prospective and larger studies to get a direct conclusion, we found that type 1 diabetic patients with less EAC and more UGAG are more likely to have diabetic retinopathy.
Yenice
Ozlem
O
Ophthalmology Department, Marmara University School of Medicine, Istanbul, Turkey. yeniceozlem@yahoo.com
Kazokoğlu
Haluk
H
Ozcan
Eda
E
Yüksel
Meral
M
Adigüzel
Göksenin
G
Haklar
Goncagül
G
Yavuz
Dilek Gogas
DG
D000328:Adult; D000423:Alcian Blue; D000838:Anions / Q000378:metabolism; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000378:metabolism / Q000652:urine*; D003930:Diabetic Retinopathy / Q000097:blood / Q000378:metabolism / Q000652:urine*; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005260:Female; D006025:Glycosaminoglycans / Q000652:urine*; D006801:Humans; D008297:Male
D000838:Anions; D001786:Blood Glucose; D006025:Glycosaminoglycans; D000423:Alcian Blue