VDR Gene Polymorphisms, Interaction with Smoking and Risk of Periodontal Disease in Japanese Women: the Kyushu Okinawa Maternal and Child Health Study

Abstract

Epidemiological evidence on the relationship between vitamin D receptor (VDR) polymorphisms and periodontal disease is inconsistent. We investigated associations between four VDR single-nucleotide polymorphisms (SNPs) including rs731236 (TaqI), rs7975232 (ApaI), rs1544410 (BsmI) and rs2228570 (FokI), and the risk of periodontal disease among young Japanese women. Cases included 131 women who had at least one tooth with a probing depth of 3.5mm or deeper. Controls included 1019 women without periodontal disease. Adjustment was made for age, region of residence, education, toothbrushing frequency and use of an interdental brush. Compared with the AA genotype of SNP rs731236, the GG genotype had a significantly increased risk of periodontal disease: the adjusted OR was 3.68 (95% confidence interval: 1.06-12.78). There were no significant relationships between SNPs rs7975232, rs1544410 or rs2228570 and periodontal disease. None of the haplotypes were significantly related to periodontal disease. Compared with subjects with the AA or AG genotype of SNP rs731236 who had never smoked, those with the GG genotype who had ever smoked had a significantly increased risk of periodontal disease; nevertheless, neither multiplicative nor additive interaction was significant. The additive interaction between SNP rs7975232 and smoking was significant, although the multiplicative interaction was not statistically significant. No multiplicative or additive interactions were observed between the other SNPs and smoking. Our results indicated that VDR SNP rs731236 might be associated with periodontal disease. In addition, we present new evidence for a biological interaction between VDR SNP rs7975232 and smoking that affects periodontal disease.