Periodontitis and diabetes: Research highlights opportunities for early risk identification

Published in The Lancet Public Health in August, the systematic review and meta-analysis examined the relationship between oral disease and diabetes over time. Drawing on 28 longitudinal studies from 16 countries involving more than 300,000 participants, the researchers found that individuals with periodontitis had an 18%–25% higher occurrence of newly diagnosed Type 2 diabetes during follow-up. Partial and complete tooth loss were also associated with subsequent diabetes diagnoses. Dr Botelho, a co-author of the study and head of the Translational One Medicine research group at the Egas Moniz School of Health and Science in Almada, Portugal, discusses the implications of these findings for clinical practice and opportunities for integrating oral health into diabetes prevention and management.

Dr Botelho, your meta-analysis found that people with periodontitis had a higher occurrence of newly diagnosed Type 2 diabetes during follow-up. What does this add to our understanding of the relationship between periodontal and metabolic health, and how should clinicians interpret the findings?
Our findings reinforce the growing evidence that oral health and metabolic health are closely interconnected. Importantly, our study examined longitudinal evidence, allowing us to investigate the direction of associations over time rather than simply whether periodontitis and diabetes coexist.

Second, individuals with fewer functional teeth may experience difficulties consuming certain nutritious foods, including fibrous vegetables, fruit and other foods requiring effective mastication. These changes may contribute to poorer dietary quality and potentially affect metabolic health.

We should also recognise that tooth loss is influenced by broader social determinants of health, including socio-economic circumstances, access to dental care, smoking and other health-related behaviours. Many of these factors are also associated with diabetes. For these reasons, I believe that tooth loss could serve as a valuable clinical indicator of increased metabolic vulnerability, although it should not be considered an independent diagnostic marker of diabetes. In practical terms, extensive tooth loss, particularly when combined with periodontitis, obesity, a family history of diabetes or other metabolic risk factors, provides an opportunity to discuss general health and consider whether medical assessment would be appropriate.

Based on your findings, what practical steps should dental teams take when treating patients with diabetes or those at increased risk of developing the disease?
I believe that our findings support a more proactive role for dental professionals in diabetes prevention and management. Patients with diabetes should receive regular, comprehensive periodontal assessments, together with appropriate treatment and supportive periodontal care. Given the relationship between glycaemic control and periodontal health, dentists and dental hygienists should also be aware of relevant aspects of patients’ medical histories, including diabetes diagnosis, treatment and recent glycated haemoglobin (HbA_1c) measurements, when available.

Dental professionals should also recognise that patients presenting with periodontitis, extensive tooth loss or other relevant risk indicators may benefit from an assessment of their metabolic health. This does not mean that dentists should assume responsibility for diagnosing diabetes. Rather, dental practices can become important points of contact for identifying individuals who may be at increased risk and facilitating appropriate referral to primary healthcare professionals.

Simple, validated diabetes risk questionnaires can be incorporated into routine dental appointments, particularly for patients with additional risk factors. Where appropriate, patients identified as being at elevated risk can be referred to their general practitioner for further evaluation, including HbA_1c or blood glucose testing. Our research group has previously investigated this concept and demonstrated that practical screening approaches implemented in dental settings can help identify individuals at high risk of undiagnosed diabetes.

This is particularly relevant because dental professionals may encounter patients who have not recently undergone a general medical assessment. A routine dental appointment can therefore become an additional opportunity for preventive healthcare.

Importantly, this approach should involve collaboration rather than place additional diagnostic responsibilities on dental teams without appropriate training or resources. Dentists and dental hygienists can contribute meaningfully to the early identification of broader health risks through closer communication with physicians, nurses and other healthcare professionals.

As World Diabetes Day draws attention to the global burden of diabetes, what needs to change in healthcare systems to ensure that oral health becomes an integral part of diabetes prevention and management?
World Diabetes Day provides an important opportunity to rethink how we organise healthcare. Despite the growing scientific evidence connecting oral and systemic health, dentistry and general medicine continue to operate largely as separate systems in many countries. This fragmentation represents a missed opportunity for prevention, early detection and integrated management of chronic disease.

Our findings suggest that oral health should be recognised as an integral component of diabetes care rather than an optional or secondary consideration. At the clinical level, this means incorporating oral health assessments and preventive dental care into diabetes management pathways. Patients diagnosed with diabetes should receive appropriate information about their increased vulnerability to periodontal disease and the importance of regular dental examinations.

Meaningful integration will require changes beyond individual clinical practice. Healthcare systems need stronger communication between dental and medical professionals, shared prevention strategies, interdisciplinary training and reimbursement structures that support preventive and coordinated care. Public health policies should also address persistent inequalities in access to oral healthcare, particularly among populations disproportionately affected by diabetes and other non-communicable diseases. From a research perspective, we need further longitudinal studies and well-designed interventions to better understand the mechanisms linking these conditions and determine whether integrated prevention and treatment strategies can improve long-term health outcomes.

Ultimately, I believe that we need to move away from the traditional separation between oral health and general health. The mouth is not disconnected from the rest of the body, and our healthcare systems should reflect that reality. If there is one message I would like to highlight on World Diabetes Day, it is that protecting oral health is part of protecting overall health. Strengthening collaboration between dental and medical professionals could help us identify vulnerable individuals earlier, improve disease management and promote healthier lives.