Objective: Cytokines produced by various cells are strong local mediators of inflammation. Interleukin-1beta (IL-1β) and C-reactive protein (CRP) play essential roles in the development and progression of diabetes mellitus (DM). Thus periodontal diseases could be related to DM via the same mediators of inflammation. To evaluate plasma and gingival crevicular fluid (GCF) levels of IL-1β and CRP in adolescents with DM to further investigate whether DM has an impact on the levels of inflammation factors at an early stage, and to analyze the risk of developing periodontal diseases in adolescents with DM.

Methods: A total of 121 adolescents aged from ten to sixteen years were enrolled, 41 adolescents diagnosed with diabetes mellitus were collected in the DM group, and 80 nondiabetic adolescents as the control group. The periodontal indices of each individual were recorded, including plaque index (PLI), modified bleeding index (mBI), probing depth (PD) and attachment loss (AL). GCF and intravenous blood samples were collected, and CRP and IL-1β levels were detected by enzyme-linked immunosorbent assay (ELISA).

Results: (1) PLI of DM group and control group were 1.23±0.05 and 0.95±0.04 separately, with significant difference (P=0.001). DM group and control group had mBI of 0.80±0.08 and 0.51±0.06 separately, with significant difference (P=0.003). Attachment loss was found in none of the subjects. PDs of DM group and control group were (2.37±0.51) mm and (2.31±0.05) mm separately, and there was no significant difference. (2) CRP in GCF was only detectable in partial of the individuals, with a detectable rate of 22.9% (11/48) in total. The detectable rate of CRP in GCF was significantly higher in DM group (38.5%) than that in control group (4.5%, P=0.006). The plasma level of CRP in DM group [0.23 (0.15, 1.89) mg/L] was higher than that in control group [0.19 (0.12, 4.18) mg/L], but without significance (P=0.776). (3) The plasma levels of IL-1β in DM group and control group were (14.11±0.57) ng/L and (14.71±0.50) ng/L separately, but there was no significance (P=0.456). GCF levels of IL-1β in DM group and control group were (12.91±1.95) μg/L and (17.68±3.07) μg/L, without significant difference (P=0.185).

Conclusion: Periodontitis was not observed in adolescents with DM at an early stage. However, the rising levels of periodontal indices and CRP in GCF, might indicate that adolescents with DM have a higher risk of developing periodontal diseases in the future.