Advanced glycation index and its association with severity of diabetic retinopathy in type 2 diabetic subjects.
BACKGROUND
This study investigates the association of advanced glycation index (AGI), a simple assay to detect advanced glycation endproducts (AGEs) in serum, with severity of diabetic retinopathy (DR) in type 2 diabetic subjects.


METHODS
The study included 188 type 2 diabetic subjects without DR, 153 subjects with nonproliferative DR, 41 subjects with proliferative DR, and 188 control participants. Serum levels of AGEs were monitored with a spectrofluorimeter by recording Maillard-specific fluorescence.


RESULTS
AGI values increased with severity of DR (analysis of variance, P<.0001). Among diabetic subjects, AGI (mean+/-S.E.) was higher among subjects with nonproliferative diabetic retinopathy (NPDR; 6.7+/-0.1 U) and proliferative diabetic retinopathy (PDR; 9.1+/-0.3 U) than among subjects without DR (P<.0001). By arranging the levels of serum AGI in quartiles, the proportion of PDR subjects increased with increasing AGI values, with maximum subjects in the last quartile (trend chi(2)=60.239, P<.0001). AGI was associated with NPDR even after adjusting for age, gender, duration of diabetes, and glycated hemoglobin [odds ratio (OR)=1.33; 95% confidence interval (95% CI)=1.12-1.57; P=.001]. Similarly, AGI showed a significant association with PDR even after adjusting for various risk factors (OR=2.47; 95% CI=1.75-3.47; P<.0001). Receiver-operating-characteristics curve analysis revealed that the threshold level of 8.07 U had a 78% sensitivity, an 83.6% specificity, and an 86.1% accuracy for detecting PDR.


CONCLUSIONS
AGI showed a significant association with the severity of DR and, hence, could be used as a prognostic tool to predict the development and progression of DR.
Anitha
Balaji
B
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Center, Gopalapuram, Chennai, India.
Sampathkumar
Rangasamy
R
Balasubramanyam
Muthuswamy
M
Rema
Mohan
M
D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications*; D003930:Diabetic Retinopathy / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012720:Severity of Illness Index
D006442:Glycated Hemoglobin