Effects of vitamin D receptor gene polymorphism and clinical characteristics on risk of diabetic retinopathy in Han Chinese type 2 diabetes patients

• Diabetes duration, systolic blood pressure and HbA1c were associated with increased risk of diabetic retinopathy.
• The VDR rs2228570 T allele and TAA haplotype were associated with the onset of diabetic retinopathy.
• The VDR gene might be a good biomarker candidate of diabetic retinopathy in Chinese type 2 diabetes patients.

PurposeThe purpose of this study was to investigate the association of VDR polymorphism with development of retinopathy in a Han Chinese population with type 2 diabetes mellitus.Materials and methodsA total of 204 T2DM patients were subdivided into groups without diabetic retinopathy (NDR, n = 110) and those with DR (n = 94). VDR rs2228570 (FokI:C > T), rs1544410 (BsmI:G > A), and rs7975232 (Apal:A > C) polymorphism was assayed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP).ResultsDiabetes duration (10.0 vs. 5.0 years, P < 0.01) was longer, systolic blood pressure (143.98 ± 24.31 vs. 135.11 ± 15.23, P < 0.01), and HbA1c (9.2 ± 2.06 vs. 8.35 ± 1.62, P < 0.01) were higher in DR than in NDR patients. Distribution frequencies of the rs2228570, rs1544410, and rs7975232 genotypes followed the Hardy–Weinberg equilibrium. VDR rs2228570 TT genotype frequency was significantly higher in DR (n = 30; 31.9%) than in NDR patients (n = 14; 12.7%; P < 0.01). DR patients carried more rs2228570 T alleles (n = 113; 60.1%) than did NDR patients (n = 89; 40.5%; P < 0.01). Genotype frequencies of rs1544410 and rs7975232 in NDR and DR patients were not different. Logistic analysis confirmed that diabetes duration (odds ratio (OR) 1.108, P < 0.01), SBP (OR 1.022, P < 0.05), HbA1c (OR 1.267, P < 0.05), and the VDR rs2228570 T allele (OR 1.467, P < 0.01) were independently associated with DR risk. TAA haplotype frequency was significantly higher in DR (24.0%) than in NDR (16.1%) patients (P < 0.05).ConclusionsDiabetes duration, SBP, HbA1c, and the rs2228570 T allele were associated with increased risk of DR. VDR rs2228570 might be good candidate biomarker of DR in Han Chinese T2DM patients.