Biomarker Expression, Microbial Distribution and Experimental Gingivitis in Type1 Diabetics

Systemic inflammatory diseases such as diabetes, create an altered host environment, increasing susceptibility to gingivitis. Currently, limited knowledge exists of relationships between gingivitis, microbiota, and oral biomarker expression in type 1 diabetics.

Objective:To determine gingival crevicular fluid(GCF) biomarker expression and microbial distribution in subgingival plaque biofilm samples(SP) for type 1 diabetic versus non-diabetic subjects during experimental gingivitis(EG).

Methods:Nine type1 diabetics and nine age/gender matched healthy patients were monitored for 35 days. Hygiene practices ceased from D0-21. GCF, SP, PI and GI scores were acquired from the mesiobuccal sites at each tooth from D0-35. IL-1ß, IL-8, MMP-8, MMP-9 were quantified by ELISA and 40 subgingival microbial species assessed using DNA-DNA hybridization.

Results:IL-1ß expression in diabetics was significantly elevated over healthy individuals(mean difference=81.2%) and between D0-D14 and D21, from D35-D14 and D21(p<0.01). Mean MMP-8, -9, and IL-8 expression in diabetics was not significantly different, exhibiting differences of 55.1-68.8%. Diabetic patients possessed more sites with GI scores ³2 on D7 and D21. IL-1ß, MMP-8, and MMP-9 expression peaked at D21, before resuming oral hygiene. At D21, higher counts of Streptococcus gordonii (p<0.01) were noted in diabetic subjects. Between D0 and D21, higher counts of P. intermedia and Fusobacterium nucleatum polymorphum(p<0.01) were observed in diabetics. At D21, significant correlation was found between MMP-9, Streptococcus gordonii, S. oralis. and S. sanguis(all p<0.01) for healthy patients. Red and orange complex species counts significantly increased(p<0.05) in both groups between D0 and D21.

Conclusions:Mean GCF biomarker expression was elevated in diabetic versus healthy individuals during EG, however, this response did not result from differences in mean PI or microbiota. Similar subgingival microbiological distribution was observed between healthy and diabetic patients, indicating limited impact of diabetes on microbial colonization.

Funded by the Clinical Research Foundation for Promotion of Oral Health, University of Berne, and Swiss Society of Odontology(grant#212).