Periodontal disease & the whole body

One of the most robustly studied associations. Periodontitis is independently associated with increased risk of atherosclerotic cardiovascular disease, though causality is still debated. Treating periodontitis improves endothelial function and is associated with measurable reductions in systemic inflammatory markers, particularly hs-CRP. Patients are sometimes referred from a physician for an elevated marker, which uncovers untreated periodontal disease.

Mechanism: Chronic periodontal infection contributes to systemic inflammation and bacteremia; periodontal pathogens have been detected in atheromatous plaques, promoting endothelial dysfunction and atherogenesis. This systemic inflammatory load is measurable through blood biomarkers such as high-sensitivity C-reactive protein (hs-CRP) and myeloperoxidase (MPO).

Measurable markers: High-sensitivity C-reactive protein (hs-CRP), Myeloperoxidase (MPO)

Strong, well-documented two-way relationship. Periodontitis worsens glycemic control, and periodontal treatment produces a clinically meaningful reduction in HbA1c (~0.4%) in people with type 2 diabetes.

Mechanism: Periodontal inflammation raises systemic inflammatory mediators (e.g., TNF-α, IL-6) that promote insulin resistance; the relationship is bidirectional.

Periodontitis is associated with preterm birth, low birth weight, and pre-eclampsia. The association is consistent, but interventional trials have not reliably shown that treatment during pregnancy reduces these outcomes, so causality is uncertain.

Mechanism: Periodontal pathogens and inflammatory mediators may reach the fetoplacental unit via bacteremia, potentially triggering an inflammatory cascade.

Particularly relevant in dependent and institutionalized older adults. Oral hygiene interventions may reduce pneumonia risk and pneumonia-related deaths in high-risk groups, such as dependent older adults, though the evidence from nursing homes is low certainty.

Mechanism: Oral pathogens in dental plaque can be aspirated into the lower airway; poor oral hygiene serves as a reservoir for respiratory pathogens.

Periodontitis and RA are linked epidemiologically and mechanistically, sharing inflammatory pathways. Periodontal treatment may modestly improve RA disease activity in some studies.

Mechanism: Porphyromonas gingivalis produces an enzyme (PPAD) that citrullinates proteins, potentially driving the autoimmune response underlying RA.

Periodontitis is associated with reduced kidney function and higher CKD prevalence/mortality, plausibly via shared inflammatory and vascular pathways.

Mechanism: Systemic inflammation from periodontitis may contribute to the inflammatory burden affecting renal function.

An emerging association supported by epidemiologic and laboratory data. Evidence is suggestive but not yet causal, and is an active area of research.

Mechanism: Periodontal pathogens (e.g., P. gingivalis and its gingipains) and systemic inflammation have been proposed to contribute to neurodegeneration.

Cohort studies link periodontitis/tooth loss with modestly increased risk of certain cancers. Associations are real but small and confounded by shared risk factors such as smoking.

Mechanism: Chronic inflammation and specific periodontal pathogens (e.g., Fusobacterium nucleatum, P. gingivalis) have been implicated in carcinogenesis at some sites.

Several observational studies report an association between chronic periodontitis and erectile dysfunction, but the evidence base is limited and heavily confounded by shared cardiovascular risk factors.

Mechanism: Shared endothelial dysfunction and systemic inflammation are the proposed common pathway.