Vitamin D receptor polymorphism (−1056 Taq-I) interacts with smoking for the presence and progression of periodontitis

Aim: The aim of this analysis was to investigate the relationship between a vitamin D receptor (VDR) polymorphism and the diagnosis and progression of periodontitis. Material and Methods: Data were derived from two different studies, including 231 subjects with healthy periodontium, 224 aggressive periodontitis and 79 chronic periodontitis (CP) patients in a case-control investigation. Sixty-one of these CP patients also took part in an observational study with a 1-year follow-up, in which progression of periodontitis was determined at the subject level. All 534 subjects provided a blood sample from which genomic DNA was extracted to study VDR - 1056 TaqI polymorphism. Results: The interaction between smoking and VDR polymorphism was associated with the diagnosis of periodontitis in Caucasians [p = 0.001, odds ratio (OR) = 1.33, 95% confidence intervals (CI) = 1.12-1.57] and all subjects (p = 0.033, OR = 1.60, 95% CI = 1.04-2.48). In the longitudinal study, subjects were divided into two clusters at 1 year according to the median number of progressing sites (Acumulative attachment loss >2mm). Logistic regression analysis revealed that the interaction between VDR Taq-I polymorphism and smoking showed limited evidence of association with the "severe progression" cluster (p = 0.033, OR = 15.24, 95% CI= 1.24-187.42). Conclusions: Vitamin D receptor Taq-I TT polymorphism was moderately associated with both the presence and the progression of periodontitis in smokers, while no association was detected in non-smoking individuals. VDR genetic factors may interact with smoking in the pathogenesis of periodontitis.