Association between HbA1c chairside values and periodontitis

Diabetes and prediabetes cases are steadily increasing worldwide every year. Screening and early detection are crucial to reduce complications and the related costs for its treatment to the healthcare services. Therefore, the aim of this cross-sectional study was to investigate the potential associations between HbA1c measured chairside and periodontitis and to assess the usefulness of a chairside test for diabetes screening in a dental setting. Data were collected from 911 patients participating in an Oral, Dental and Craniofacial Biobank at King's College London (United Kingdom). Self-reported medical and dental history were taken. HbA1c test was carried out chairside and associated with periodontal clinical data. From a total of 911 patients, 6.0 % were periodontally healthy, 11.3 % had gingivitis and 82.7 % had periodontitis stage I to IV. A total of 104 self-reported a diagnosis of diabetes type II. The mean HbA1c value was 5.71 ± 0.94 %. Excluding self-reported diabetics, 227 (28.7 %) were in the pre-diabetes range (HbA1c between 5.7-6.3 %) and 58 (7.3 %) were in the 'diabetes range'. The HbA1c levels increased from diagnosis of periodontal health (5.43 ± 0.51 %), gingivitis (5.51 ± 0.91 %) and periodontitis (5.76 ± 0.97 %) (p = 0.004). Adjusted linear regression showed a significant association between age and HbA1c (p < 0.001), with a border-line association for periodontal diagnosis (p = 0.054). Age showed similar findings after excluding self-reported diabetics (p < 0.001). Logistic regression (HbA1c <5.7 % vs. ≥5.7 %) confirmed significant associations with age (p < 0.001) and BMI (p = 0.038), while periodontal diagnosis was not statistically significant (p = 0.070). Periodontitis showed a border-line association with higher levels of HbA1c after adjusted analysis. Around a third of patients seen in this secondary care dental setting were found to have HbA1c in the diabetes or pre-diabetes range while they were not aware about their diabetic status, confirming that the dental visit could be an important opportunity for early detection of undiagnosed hyperglycaemia.