Mediating Effects of Systemic Inflammation in the Association Between Non-Surgical Periodontal Therapy (NSPT) and Hypertension: Testing a Hypothesis.

AIMS: To ascertain the causal relationship between non-surgical periodontal therapy (NSPT) and incident hypertension and to investigate the mediating role of systemic inflammation in this association.

METHODS

We conducted a retrospective cohort study of patients diagnosed with periodontitis between 2015 and 2021 at our institution. Participants were stratified into two groups: those who received NSPT (treatment group) and those who did not (control group). Elevated systemic inflammation was assessed using composite inflammatory markers measured from initial treatment through 1 year after diagnosis. The primary outcome was the development of hypertension during follow-up. Causal mediation analysis evaluated the mediating role of inflammation in the NSPT-hypertension association.

RESULTS

Among 228 included patients (43% male, median age: 50.5 years), 47 (20.6%) developed hypertension during a median follow-up of 4.34 years (IQR 3.41-5.60). The average direct effect of NSPT on hypertension risk was consistent (control: -0.15, p = 0.012; treatment: -0.15, p = 0.012), indicating a stable protective effect. However, the mediation effect of elevated systemic inflammation was nonsignificant (p > 0.05), with a negligible proportion of the total effect.

CONCLUSION

NSPT was causally linked to reduced risk of incident hypertension, but not via systemic inflammatory pathways. Alternative mechanisms warrant investigation.