Fig. 2

Concentration of inflammatory cytokines obtained in GCF of the study groups. Inflammatory cytokines including IL-1β (A), TNF-α (B), IL-6 (C), and CRP (D) in GCF of the control group(n = 36), overweight group (n = 38) and obesity group (n = 38) were measured by ELISA. The dashed lines in the figure showed the average levels of participants without periodontitis in all the three groups (29 in total) as normal reference. All data were expressed as mean ± standard deviation, * indicated statistically significant difference compared with the normal weight group (P < 0.05), # indicated statistically significant difference compared with the overweight group (P < 0.05). One-way ANOVA and Kruskal–Wallis test were used as the statistically test