BMI Association With Gingival Fluid and Peripheral Blood Inflammatory Biomarkers
Objectives: Elevated body mass index (BMI) across life is associated with chronic low grade inflammation. The aim of this study was to investigate the association of peripheral blood inflammatory biomarkers with their gingival crevicular fluid (GCF) counterparts between lean and obese individuals independent of periodontitis.
Methods: A total of 39 periodontally healthy subjects (pocket depth (PD) ≤ 3mm, bleeding on probing (BOP) <10%) were enrolled. BMI was calculated from weight in kilograms divided by height in meters squared and was categorized according to the National Heart, Lung, and Blood Institute Clinical Guidelines. A comprehensive periodontal examination was performed. GCF and venipuncture blood samples were collected. Both GCF and blood samples were assessed for interleukin-1β, interleukin-6, interleukin-8, tumor necrosis factor-alpha, interleukin-10 and C-reactive protein (CRP).
Results: Based on BMI scores, 20 subjects were categorized as lean and 19 as obese. Wilcoxon rank-sum test showed no differences in both GCF and blood inflammatory biomarker levels between the two groups except for GCF CRP levels which were higher in obese than lean individuals (p<0.05). In all subjects, Pearson correlation analysis showed that GCF CRP levels associated with BOP (p<0.01) and PD (p<0.01); GCF IL-10 levels negatively associated with PD (p<0.01) however blood IL-10 levels positively associated with PD (p<0.01). Rank regression analysis adjusting for age, gender and race showed no associations between GCF cytokines with their blood counterparts; by contrast, CRP GCF levels were associated with their blood levels (p<0.01). BMI associated with both GCF CRP (p<0.05) and blood CRP (p<0.05), implying that the association between GCF and blood CRP is promoted by BMI.
Conclusions: Gingival cytokines are locally produced independent of their blood counterparts. GCF and blood IL-10 levels contrastingly associate with pocket depth. Obesity may influence the association between gingival and systemic inflammation.