Oral Health, Inflammation, and the Burden of Multiple Long-Term Conditions: Cross-Sectional Analyses from UK Biobank and NHANES.

Background

The contribution of oral inflammatory conditions to systemic disease burden remains underexplored within multimorbidity frameworks. Emerging evidence suggests that periodontal inflammation may play a role in the clustering of chronic diseases, yet few studies have evaluated this at a population level using robust datasets. The aims of this study were to investigate whether periodontal diseases are associated with Multiple long-term conditions (MLTCs) burden and severity in two population-based cohorts and to examine whether systemic inflammatory biomarkers mediate these associations. Materials and

Methods

We analyzed two population-based cohorts: the UK Biobank (UKB; n = 500,612) and the US National Health and Nutrition Examination Survey (NHANES; n = 10,714). MLTCs were defined as the coexistence of ≥2 chronic diseases. Associations between periodontal diseases and MLTCs were assessed using multivariable logistic and multinomial logistic regression. Causal mediation analyses examined the contribution of systemic inflammatory markers.

Results

Approximately half of all participants had MLTCs. The prevalence of periodontal diseases was 17.8% in UKB (self-reported symptoms), and 42.3% in NHANES (clinically assessed). Periodontal diseases were independently associated with greater odds of MLTCs in both UKB (OR 1.12; 95% CI 1.10-1.14) and NHANES (OR 1.22; 95% CI 1.09-1.37). Associations were stronger among adults aged ≤ 60 years. A consistent dose-response relationship was observed between periodontal status and the number and severity of chronic conditions, as well as inflammatory-related MLTCs. Mediation analyses suggested partial effects through white blood cell count, neutrophils, and C-reactive protein.

Conclusions

Periodontal inflammation is independently associated with greater multimorbidity burden, particularly in younger adults. Systemic inflammation may offer a plausible biological link, and these findings position oral health as an underrecognized and modifiable target in multimorbidity prevention and management frameworks, warranting prospective investigation.