Association between periodontitis and diabetes

Background + Aims

• The relationship between diabetes and periodontitis is considered bidirectional – diabetes can worsen periodontal health, while periodontal inflammation may contribute to disturbances in glucose regulation.
• Understanding this relationship requires examining both people who already have diabetes and those who may develop it later.
• This study aimed to:
  • Update the evidence on associations between periodontitis and glycaemic control, new-onset type 2 diabetes, diabetes-related complications and gestational diabetes.

Materials + Methods

• This systematic review updated the 2013 EFP–AAP review. 20 additional observational reports were included, covering cohort, case–control and selected cross-sectional studies. The findings were considered alongside the earlier evidence.
• Periodontal assessments included probing pocket depth, measuring the depth of the space between tooth and gum, and clinical attachment loss, indicating loss of tooth-supporting attachment.
• Outcomes included glycated haemoglobin (HbA1c), fasting glucose, glucose tolerance, new diabetes diagnoses, and diabetes-related complications.
• Study quality was assessed using the Newcastle–Ottawa Scale and an adapted assessment for cross-sectional studies.
• Findings were organised by clinical question and presented in evidence tables.

Results

• People without diagnosed diabetes
  • The overall evidence linked periodontitis with higher HbA1c, fasting glucose and greater prevalence of prediabetes.
  • Several small studies found no significant differences.
• Development of diabetes:
  • 6 studies across the original review and update included approximately 72,700 participants.
  • 2 new Taiwanese cohorts reported an adjusted hazard ratio of 1.19 (95% CI 1.10–1.29) for developing type 2 diabetes and 1.33 (95% CI 1.09–1.63) for developing hyperglycaemia, including diabetes.
  • These represent higher rates of developing the respective outcomes during follow-up, rather than absolute increases in risk.
• People with type 2 diabetes:
  • Periodontitis was generally associated with poorer glycaemic control, but findings were inconsistent and less robust than those in people without diabetes.
• Diabetes-related complications:
  • The combined evidence linked periodontitis with more complications, including retinopathy, kidney disease, neuropathic foot ulceration and cardiovascular outcomes.
• Type 1 and gestational diabetes:
  • Evidence was insufficient to establish the relationship with glycaemic control in type 1 diabetes.
  • Findings for gestational diabetes were limited and inconsistent.

Limitations