Association Between Single Nucleotide Polymorphisms in the Vitamin D Receptor and Incidence of Dry Eye Disease in Chinese Han Population

Background: Dry eye disease (DED) is a chronic dysfunction of the ocular surface and has become an important public problem. Vitamin D receptor (VDR) gene polymorphism has been found to be associated with different kinds of diseases. The relationship between single nucleotide polymorphisms (SNPs) in the VDR gene should be studied. Material/Methods: In the present case-control study, we investigated the association of VDR gene polymorphism with DED risk. Clinical data including age, gender, body mass index (BMI, kg/m(2)), smoking history, diabetes, and blood pressure were recorded. Serum 25-hydroxy vitamin D (25[OH]D) was chosen as the main parameter that reflected the level of vitamin D. We identified SNPs of VDR gene Apa-1, Bsm-1, Fok-1, and Taq-1 in both DED cases and healthy controls. Results: A total of 124 DED cases and 135 healthy controls were included in this study. It was reported that aa in Apa-1 (OR=2.803, 95% CI, 1.350-5.820) and tt in Taq-1 (OR=0.362, 95% CI, 0.141-0.930) were associated with increased the risk of DED. Analysis of the allele frequencies of VDR gene polymorphisms among DED patients and healthy controls showed that allele differences in Apa-1 were significantly associated with higher risk. Conclusions: SNPs of VDR gene (Apa-1 and Taq-1) were associated with the risk of DED. No significant association of Bsm-1 and Fok-1 in VDR gene demonstrated significant effect in the incidence of DED. Thus, we found that several SNPs of VDR gene could provide significant pathogenic effects in the risk of DED.