Relationship between TNF-α gene polymorphism-308 and type 2 diabetes with periodontitis

AIM: To investigate the gene polymorphism-308 of tumor necrosis factor alpha (TNF-α) in the relation with the susceptibility to periodontitis combined with type 2 diabetes mellitus (DM) and its severity.METHODS: Human DNA samples were obtained from 240 DM patients with periodontitis (periodontitis group, n=120) and without periodontitis (control group, n=120). All patients were genotyped by PCR-RFLP analysis. The frequencies of genotypes and alleles were analyzed. Sulcus bleeding index (SBI) and probing depth (PD) in all patients were measured. The polymorphism-308 of TNF-α gene in the relation with the susceptibility to periodontitis combined with DM and its severity was analyzed.RESULTS: No significant difference in the frequency of genotype and allele was found between DM patients with mild periodontitis and DM patients without periodontitis (P>0.05). However, the frequencies of these genotypes and alleles in DM patients with moderate and severe periodontitis were significantly higher than those in DM patients without periodontitis (P<0.01). The findings showed that the level of TNF-α was associated with SBI and PD (P<0.01).CONCLUSION: TNF-α -308 G/A polymorphism is not associated with DM patients with mild periodontitis, whereas it may have a role in pathogenesis and prognosis of moderate and severe periodontitis combined with DM through TNF-α level.