Assessment of Gingival and Systemic Glucose Dynamics During a Glucose Challenge in Normoglycemic Individuals

Aim This study aimed to investigate whether dynamic glucose responses differ between systemic and periodontal compartments in normoglycaemic individuals with periodontal health or periodontitis, and explore whether these are associated with interdental plaque pH. Methods In this single-centre cross-sectional study, 20 normoglycaemic adults were allocated to a periodontal health group (n = 10) or a periodontitis group (n = 10). Participants completed a two-hour oral glucose tolerance test, comparing venous blood, peripheral finger blood, and gingival crevicular blood responses. Interdental plaque pH was assessed using the Stephan curve. Intergroup differences in glucose response within sites were analysed with a repeated-measures ANOVA. Glucose responses across sites, interdental pH response and their association were explored using linear mixed models. Results Participants with periodontitis displayed significantly different gingival crevicular glycaemic responses to those with periodontal health [group × time interaction: F(3.24, 58.28) = 3.58, p  = 0.017, η²G = 0.086]. This was attributed to a significantly greater peak concentration at 30 minutes [estimated mean difference 37.5 mg/dL, 95% CI 7.1–67.9, p  = 0.018]. No significant differences between groups were observed in the systemic compartments, or in the interdental pH response. Conclusions Normoglycaemic individuals with periodontitis exhibit a distinct dynamic glucose response that is not reflected systemically. These findings support a potential role for local glucose dysregulation in periodontitis in otherwise normoglycaemic patients