Direct impact of psoriasis on gingival crevicular fluid levels of VEGF-A in periodontitis patients: a mediation analysis

Introduction: Emerging evidence suggests that psoriasis and periodontitis are linked via systemic inflammation. However, the role of angiogenesis as an additional connecting mechanism between these diseases remains unclear. Methods: This case control study explored the effect of psoriasis on the gingival crevicular fluid (GCF) levels of vascular endothelial growth factor A (VEGF-A) in patients with different stages of periodontitis. Thirty-one patients with psoriasis (P) and thirty healthy controls (C) underwent physical and intraoral evaluations, with diagnoses confirmed by dermatologists and periodontists. GCF VEGF-A was measured using a multiplex-bead immunoassay. Statistical analyses included Fisher exact tests, Student’s T-tests, linear regression models, and mediation analyses. Results: Psoriasis patients had significantly lower GCF VEGF-A levels compared to controls (p=0.008). Psoriasis was negatively associated with GCF VEGF-A (p=0.006), while severe periodontitis was positively associated with GCF VEGF-A levels, regardless of tobacco use (p=0.027). Further analyses revealed that severe periodontitis significantly increased GCF VEGF-A levels only in the C group (p=0.038), but not in psoriasis patients (p>0.610). Mediation analyses confirmed a significant direct and total effect of psoriasis on GCF VEGF-A (p>0.002), with no significant indirect effect through periodontitis (p=0.699). Discussion: Psoriasis and severe periodontitis are associated with GCF levels of VEGF-A in opposite and independent ways. In subjects with psoriasis, the impact of the dermatosis is direct with no mediation from periodontitis.