Oral health in diabetes: An overlooked, but modifiable risk factor in metabolic and cardiovascular care

Reference: July-August 2026 | Issue 4 | Vol 19 | Page 62

Periodontal disease has been described as a complication of diabetes due to its strong and consistent association with chronic hyperglycaemia and glycaemic control

Diabetes mellitus is associated with well-recognised microvascular and macrovascular complications, including retinopathy, nephropathy, neuropathy, and cardiovascular disease. Less frequently discussed, but just as important, is periodontal disease, a chronic inflammatory condition affecting the supporting structures of the teeth.

Periodontal disease has been described as a complication of diabetes due to its strong and consistent association with chronic hyperglycaemia and glycaemic control.¹ However, unlike other complications, it remains under-recognised and is not routinely embedded within structured diabetes review or diabetes education.

In Ireland, where the prevalence of diabetes continues to rise, integrating oral health into routine care represents an important opportunity to enhance preventative practice. Promoting oral health strongly aligns with the Health Service Executive’s ‘Make Every Contact Count’ (MECC) initiative, supporting brief, opportunistic interventions that improve long-term health outcomes.

Pathophysiology: Why diabetes increases periodontal risk

Persistent hyperglycaemia in individuals with diabetes impairs immune function and promotes chronic oral inflammation, increasing the risk of periodontal disease. Key mechanisms include:
✽ Impaired neutrophil function
✽ Altered cytokine response
✽ Increased formation of advanced glycation end products
✽ Microvascular changes reducing tissue perfusion
✽ Impaired collagen turnover and delayed wound healing.

These processes create a pro-inflammatory environment in which periodontal tissues are more susceptible to bacterial insult and destruction.^3,4 Additionally, elevated glucose levels in saliva promote the growth of pathogenic oral bacteria and plaque accumulation, further increasing the risk of periodontal breakdown. Patients with poor glycaemic control, longer duration of diabetes, smoking history, and co-existing cardiovascular disease are at particularly high risk of severe periodontal disease.

The bidirectional relationship

Diabetes → periodontitis: Elevated blood glucose intensifies inflammatory responses and weakens host defences, leading to a higher incidence and severity of periodontal disease.
Periodontitis → worsened glycaemic control: Periodontal inflammation increases circulating pro-inflammatory mediators, including tumour necrosis factor-alpha, interleukin-6, and C-reactive protein (CRP), which contribute to insulin resistance and worsening glycaemic control.⁵

Meta-analyses demonstrate that non-surgical periodontal therapy may reduce HbA1c by approximately 0.3-0.6 per cent in individuals with type 2 diabetes.^6,7 This reduction is clinically significant and comparable to the addition of a second oral glucose-lowering agent. This evidence positions periodontal care as a vital aspect of metabolic optimisation, not just a matter of dental management.

Oral health and cardiovascular risk

Systemic inflammation and endothelial dysfunction are key factors linking periodontal disease to cardiovascular disease. Chronic periodontal infection has been associated with:
✽ Increased atherosclerotic plaque burden
✽ Elevated CRP levels
✽ Endothelial dysfunction.

These mechanisms contribute to cardiovascular risk, which remains the leading cause of morbidity and mortality in people with diabetes.^8.9 Integrating oral health education into diabetes and cardiovascular care pathways supports a more comprehensive, multidisciplinary approach to risk reduction.

Clinical manifestations in diabetes

Common oral complications in diabetes include:
✽ Gingivitis (red, swollen, bleeding gums)
✽ Periodontitis (pocket formation, bone loss, tooth mobility)
✽ Xerostomia (dry mouth) – Dry mouth, whether related to autonomic neuropathy, medications, or chronic hyperglycaemia, further increases the risk of dental caries and infection
✽ Oral candidiasis
✽ Delayed healing following dental procedures.

Integrating oral health into diabetes review: A MECC approach

Oral health education can be easily incorporated into routine diabetes care using a MECC-based approach. Simple screening questions include:
✽ Do your gums bleed when brushing?
✽ When was your last dental review?
✽ Do you experience dry mouth?
✽ Have you noticed loose teeth or gum swelling?

These brief, structured interactions enable clinicians to identify risk early, reinforce key health messages, and facilitate timely referral to dental services. Embedding oral health within MECC supports opportunistic prevention and empowers patients to take an active role in their self-management.

Practical recommendations for clinicians

✽ Incorporate oral health education into structured diabetes review
✽ Encourage regular dental attendance (at least annually)
✽ Reinforce twice-daily tooth brushing with fluoride toothpaste
✽ Promote interdental cleaning
✽ Support smoking cessation
✽ Optimise glycaemic control.

These interventions are low-cost, and align with national preventative health strategies.

Conclusion

Oral health in diabetes is not cosmetic; it is metabolic and cardiovascular. Periodontal disease contributes to systemic inflammation, insulin resistance, and increased cardiovascular risk. Maintaining good oral health contributes to better glycaemic control and overall health outcomes. Integrating oral health into routine diabetes care represents an achievable, evidence-based opportunity to enhance patient care. Through alignment with MECC principles, clinicians can deliver meaningful, preventative interventions that support long-term health in people living with diabetes.