Basic fibroblast growth factor (bFGF) expression is implicated in proliferative diabetic retinopathy (PDR). The aim of this study was to investigate the association of genetic polymorphisms (−553T/A, −834T/A and −921C/G) in the promoter region of the bFGF gene with PDR in patients with type 2 diabetes. The second aim was to determine whether serum levels of bFGF are affected by genetic factors.Methods
In this cross-sectional case–control study 313 unrelated Caucasians (Slovene population) with type 2 diabetes mellitus were enrolled: 206 patients with PDR and the control group of 107 subjects with type 2 diabetes of duration of more than 10 years who had no clinical signs of diabetic retinopathy. We analysed serum bFGF levels in 78 subjects with type 2 diabetes and 25 subjects without diabetes.Results
The AT genotype of the −553T/A polymorphism was present in 31 (15.0%) PDR patients and in seven (6.5%) controls (P= 0.03, odds ratio = 2.0, 95% confidence interval = 1.0–3.9). The AT genotype of the −834T/A polymorphism was present in 12 (5.8%) PDR patients and in 15 (14.0%) controls (P= 0.01, odds ratio = 0.4, 95% confidence interval = 0.2–0.8). Significantly higher bFGF serum levels were demonstrated in diabetics with the AT genotype of the −553 polymorphism compared with diabetics with the TT genotype, whereas the −834 and −921 polymorphisms failed to affect serum bFGF levels.Conclusions
We may conclude that the AT genotype of the 553 T/A polymorphism was associated with PDR in Caucasians with type 2 diabetes, therefore it might be used as a genetic marker of PDR in Caucasians, whereas carriage of the AT genotype of the −834 T/A polymorphism might decrease PDR risk.