Evaluation of gingival crevicular fluid apelin levels in relation to periodontal status and type 2 diabetes

Abstract

Aim: Adipokines in gingival crevicular fluid (GCF) may reflect systemic metabolic and inflammatory conditions, including diabetes and periodontitis. Apelin, a multifunctional peptide expressed in adipose tissue and various organs, is involved in both metabolic regulation and inflammatory pathways and therefore represents a biologically relevant mediator for exploring the link between diabetes mellitus and periodontitis. This study aimed to investigate GCF apelin levels in periodontally healthy individuals, patients with periodontitis, and those with periodontitis and Diabetes Mellitus (DM).

Methodology: Ninety participants were enrolled and equally distributed into three groups (n=30 each): Healthy, periodontitis, and periodontitis+DM. Clinical parameters were recorded, and GCF samples were collected for apelin measurement using ELISA. Data were analyzed using nonparametric and categorical statistical tests according to the distribution and type of variables.

Results: GCF apelin levels were comparable among the periodontally healthy, periodontitis, and periodontitis+DM groups, showing no statistically significant differences (p = 0.991). An inverse correlation was observed between GCF volume and apelin concentration (r_s = –0.39; p <0.001). No significant differences were observed among the groups in terms of age, gender, or BMI (p > 0.05).

Conclusion: GCF apelin levels did not differ significantly among the study groups. The inverse correlation between apelin concentration and GCF volume, an indirect indicator of local inflammation, may reflect a relationship with local inflammatory status. These findings suggest that GCF apelin alone has limited clinical value for distinguishing periodontitis with DM. Therefore, measuring GCF apelin as a single biomarker is not recommended for identifying periodontal disease status or diabetic individuals within a periodontal population. Nevertheless, these results contribute to understanding the relationship between metabolic conditions and periodontal inflammation. Further longitudinal and mechanistic studies are needed to clarify the origin and regulation of apelin in periodontal tissues and to determine its potential role as a biomarker or therapeutic target.