Diabetes modulates gene expression in the gingival tissues of patients with chronic periodontitis

Aim: This study evaluated whether diabetes modulates gene expression [interleukin (IL)‐1 β , IL‐1ra, IL‐6, IL‐8, IL‐10; tumor necrosis factor (TNF)‐ α ; interferon (IFN)‐ γ , receptor activator of NF‐ κ B 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‐1 β , IL‐1ra, IL‐6, IL‐8, IFN‐ γ , 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‐ α between diabetic and control groups ( P > 0.05). Diabetes lowered IL‐1 β , IL‐8, IL‐10, TNF‐ α , 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.