Association of Gingival Crevicular Fluid Leptin Levels With Stages of Periodontitis: A Cross-Sectional Study

To evaluate the concentration of leptin in gingival crevicular fluid (GCF) across different stages of periodontitis according to the 2018 classification system and to investigate the association between GCF leptin levels and periodontitis stages.

A total of 119 subjects were enrolled and allocated to 3 groups: periodontitis (P, n = 77), gingivitis (G, n = 21), and periodontal health (PH, n = 21). The P group was further classified into Stages I to IV periodontitis based on staging criteria. Clinical periodontal indexes were recorded. GCF samples were collected using absorbent paper points, and leptin concentrations in GCF were determined using enzyme-linked immunosorbent assay (ELISA). Spearman correlation, multivariable regression, and receiver operating characteristic (ROC) were evaluated.

GCF leptin levels decreased progressively from the PH group to the G and P groups and declined further with increasing periodontitis stage (all P < .05). GCF leptin levels were negatively correlated with probing depth (PD) (r_s = -0.48, P < .001) and clinical attachment loss (CAL) (r_s = -0.37, P = .001). After adjustment for age, sex, and body mass index, higher GCF leptin levels were associated with a lower risk of stage III and IV periodontitis (OR = 0.74, 95% CI: 0.58 to 0.95, P = .019). The inclusion of GCF leptin improved discrimination between gingivitis and periodontitis (AUC = 0.824) and provided acceptable discrimination between stages I and II and stages III and IV periodontitis (AUC = 0.760).

GCF leptin levels were significantly associated with periodontitis stages and decreased progressively with advancing disease severity. GCF leptin can provide complementary information for the assessment of periodontal disease severity.

GCF leptin levels may serve as a complementary indicator of periodontal status and disease severity, supporting clinical assessment of periodontitis.