Association between Serum Vitamin D Levels and VDR BsmI Polymorphism in Temporomandibular Joint Dysfunction Patients (in the Iranian Population)

Abstract

BACKGROUND: Multiple studies have revealed an association between vitamin D levels, genetic polymorphisms of the VDR (vitamin D receptor) gene, and the underlying causes of various bone and cartilage disorders. PURPOSE: This study aimed to investigate the association between the BsmI polymorphism of the VDR gene and serum vitamin D levels in a group of temporomandibular joint dysfunction (TMD) patients compared to healthy controls. MATERIALS AND METHOD: Our cross-sectional study encompassed 42 TMD patients diagnosed according to the research diagnostic criteria for temporomandibular disorders (RDC /TMD) and 41 healthy subjects. Genomic DNA was prepared, the BsmI variant was analyzed by PCR-RFLP, and the serum vitamin D level was measured by ELISA technique. Chi square and ANOVA test was used for analysis and statistical significance was set at p Value < 0.05. RESULTS: The serum levels of vitamin D in the TMD group were significantly lower than those in the control group, with values of 43.52+/-18.16 ng/mL compared to 57.56+/-21.29 ng/mL (p= 0.002). The prevalence of vitamin D insufficiency was remarkably higher in the patients than in the controls, at 26.19 vs. 4.87, respectively (p= 0.008). Our analysis revealed no significant differences in the genotype and allele frequencies of the VDR BsmI variant between TMD patients and controls (p= 0.475 and p= 1.000, respectively). Additionally, our study found no significant association between the genotypes of the VDR BsmI variant and vitamin D status (p= 0.363). CONCLUSION: Monitoring vitamin D levels in TMD patients is important, as deficiency may impact disease development. Further research is needed on the role of vitamin D and VDR gene variants in managing temporomandibular disorders.