The Impact of IL1B rs1143634 and DEFB1 rs11362 Variants on Periodontitis Risk in Phenylketonuria and Type 1 Diabetes Mellitus Patients in a Latvian Population

Objectives: Periodontitis is a multifactorial disease that affects approximately 11% of the global population. The objective of this study was to examine whether, among individuals with phenylketonuria and type 1 diabetes mellitus, those with the IL1B rs1143634 and/or DEFB1 rs11362 genetic variants exhibit a higher periodontitis risk compared to healthy controls. Materials and Methods: In all, 43 phenylketonuria patients (aged 12–53), 28 type 1 diabetes mellitus patients (aged 11–40), and 63 healthy controls (aged 12–53) were included. The evaluation of periodontitis risk was conducted using the Silness–Löe plaque index, the Greene–Vermillion index, and an assessment for the necessity of calculus removal. Genetic variants rs1143634 and rs11362 were genotyped from salivary samples using restriction length polymorphism analysis. Results: The DEFB1 rs11362 variant was associated with higher Silness–Löe and Greene–Vermillion index scores in phenylketonuria patients (p = 0.011 and p = 0.043, respectively). The IL1B rs1143634 variant was associated with lower calculus removal necessity in type 1 diabetes mellitus patients (p = 0.030). Clinical examination showed the worst oral hygiene index scores for PKU patients. PKU patients also reported the least consistent tooth brushing and flossing habits. Conclusions: Genetic associations between DEFB1 rs11362 and IL1B rs1143634 variants and oral hygiene indices were observed in the PKU and T1DM groups, suggesting that genetic factors may contribute to periodontal health differences in these populations. Further research with a larger sample size is needed to confirm these findings and develop targeted oral health interventions.