Abstract
Purpose: :
To investigate whether plasma pentosidine, a well-defined advanced glycation end product, are associated with retinal hemodynamic abnormalities in patients with type 2 diabetes.
Methods: :
A retinal laser Doppler system (Canon Laser Blood Flowmeter, model CLBF 100, Canon Inc, Tokyo, Japan) was used to measure arterial diameter (D), centerline blood velocity (V), and blood flow (F) in the major temporal retinal arteries in 22 eyes of 22 patients (mean age, 61 years) without diabetic retinopathy (DR- group), 20 eyes of 20 patients (mean age, 61 years) with DR (DR+ group), and 10 eyes of 10 subjects (mean age, 64 years) without diabetes (control group). The pulsatility ratio (PR), one of resistive indices, was calculated from the blood velocity traces. The PR is expressed as the peak systolic to the end diastolic velocity ratio. Pentosidine was measured in plasma samples from 44 patients with diabetes using a commercially available competitive enzyme-linked immunosorbent assay (FSK pentosidine ELISA kit, Fushimi Pharmaceutical, Kagawa, Japan).
Results: :
The PR increased in patients with DR (4.8±1.5) compared with patients without DR (4.0±0.8) and controls (3.5±1.5) (one-way ANOVA, P=0.0033). However, there were no differences in the V, D, or F among the three groups, suggesting that the abnormally increased indices of pulsatility in the retinal arteries in patients with DR do not result in increased distal vascular resistance but are likely due to decreased vascular compliance. Plasma pentosidine increased in patients with DR (0.057±0.015) compared with patients without DR (0.047±0.012) and controls (0.044±0.010) (one-way ANOVA, P=0.0142). The PR was positively correlated with the plasma pentosidine levels in patients with diabetes (Pearson’s correlation, r=0.468, P=0.0015).
Conclusions: :
Our results indicated that the retinal arteries in patients with DR may become increasingly rigid because of increased pentosidine, and the increased vascular rigidity may be associated partly with the cause and development of DR.
Keywords: diabetic retinopathy