Salivary biomarker profiling in prediabetes-associated periodontitis: role of adiponectin, resistin, and total matrix metalloproteinase-8.

AIM: This study evaluated the diagnostic potential of salivary total matrix metalloproteinase-8 (tMMP-8), adiponectin, and resistin in prediabetic adults with and without periodontitis and examined their associations with systemic and periodontal parameters.

MATERIALS AND

METHODS

Systemically healthy and prediabetic adults, categorized by periodontal status, underwent clinical, anthropometric, and metabolic assessments. A total of 84 adults aged 25-55 years were enrolled and stratified into four groups: prediabetes with periodontitis (PreDM-PD, n = 24), prediabetes with periodontal health (PreDM-PH, n = 19), systemically healthy with periodontitis (SH-PD, n = 22), and systemically and periodontally healthy controls (SH-PH, n = 19). Unstimulated saliva was collected to quantify tMMP-8, adiponectin, and resistin by sandwich ELISA. Statistical analyses included group comparisons (one-way ANOVA with Bonferroni post-hoc correction; Kruskal-Wallis with Dunn's test for non-normally distributed variables), correlation analysis of biomarkers with systemic and periodontal measures, and principal component analysis (PCA) to define a composite inflammatory profile.

RESULTS

Participants with periodontitis had significantly higher periodontal parameters (p < 0.001). Salivary tMMP-8 was elevated in prediabetic individuals with periodontitis compared to other groups (p < 0.001), whereas adiponectin was lower in prediabetic groups versus controls (p < 0.01). tMMP-8 correlated positively with BMI, HbA1c, probing pocket depth (PPD), and clinical attachment loss (CAL). Adiponectin inversely correlated with HbA1c, PPD, CAL, and bleeding on probing. Resistin showed a weak positive correlation with CAL. PCA revealed an inflammatory profile (high tMMP-8, low adiponectin) explaining 37.1% of variance (KMO = 0.58; Bartlett's χ² = 22.86, p < 0.001), effectively distinguishing prediabetic with periodontitis from healthy controls (AUC = 0.925, p < 0.001; sensitivity 87.5%, specificity 89.5%, Youden J = 0.77) and showing acceptable accuracy in periodontal health. Between-group differences for tMMP-8, adiponectin, PPD, CAL and BoP remained statistically significant after adjustment for age (ANCOVA, all p < 0.01).

CONCLUSION

Salivary tMMP-8 and adiponectin composite profiles outperform single markers, supporting their use in non-invasive periodontal risk screening in metabolically vulnerable adults. Elevated tMMP-8 links periodontal and metabolic inflammation in prediabetes.