Aim: This study evaluated whether diabetes modulates gene expression [interleukin (IL)-1beta, IL-1ra, IL-6, IL-8, IL-10; tumor necrosis factor (TNF)-alpha; interferon (IFN)-gamma, receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG)] in sites with periodontitis.
Materials and methods: Gingival biopsies were harvested and divided into three groups--Control group: systemically and periodontally healthy subjects (n = 10); Periodontitis group: systemically healthy subjects diagnosed with chronic periodontitis (n = 20); Diabetes group: type 1 diabetic subjects, diagnosed with chronic periodontitis (n = 20). Total RNA was obtained and analyzed by quantitative polymerase chain reaction.
Results: Data analysis demonstrated that, except for OPG, mRNA levels for all factors were increased by inflammation (P < 0.001). Interleukin-1beta, IL-1ra, IL-6, IL-8, IFN-gamma, and RANKL mRNA levels were higher in the diabetic group when compared with the control non-periodontitis group (P < 0.05), whereas IL-10 and OPG were lower (P < 0.05). No difference was observed for TNF-alpha between diabetic and control groups (P > 0.05). Diabetes lowered IL-1beta, IL-8, IL-10, TNF-alpha, RANKL, and OPG mRNA levels in sites with comparable type of periodontitis (P < 0.001). Moreover, increased RANKL:OPG and IL-6:IL-10 ratios were found.
Conclusion and clinical relevance: Taken together, these data suggest that decreased levels of IL-10 and OPG may play an important role in the periodontal breakdown in diabetic patients.