Abstract
Background: Oral health has been implicated as a contributor to systemic inflammation and cardiovascular disease. However, the reverse relationship-whether systemic inflammation causally affects oral health-remains poorly defined. This study investigates the directional role of systemic inflammation in oral disease using genetic and phenotypic data from the UK Biobank.</p>
Methods: We analyzed data from 468,460 UK Biobank participants, integrating self-reported oral health measures with plasma levels of high-sensitivity C-reactive protein (hsCRP). To assess causality, we examined the IL6R single nucleotide polymorphism rs2228145 (p.Asp358Ala), a well-characterized variant associated with impaired IL-6 receptor signaling and reduced systemic inflammation.</p>
Results: Higher hsCRP tertiles were significantly associated with increased prevalence of poor oral health indicators, including tooth loss, dentures, bleeding gums, and loose teeth (all p < 0.001). Carriers of the IL6R C/C genotype exhibited significantly lower hsCRP levels and a reduced burden of oral pathology, including lower odds for toothache (OR 0.91 [95%CI 0.87-0.94]), bleeding gums (OR 0.97 [95%CI 0.94-0.99]), and loose teeth (OR 0.92 [95%CI 0.88-0.96]).</p>
Conclusion: Our findings support systemic inflammation-mediated via IL-6 signaling-as a causal determinant of impaired oral health. This study provides novel evidence for a directional link from systemic inflammation to oral disease, with potential implications for targeted immunomodulatory interventions in oral health.</p>