Recent evidence suggests a link between periodontitis (PD) and hypertension, but the nature of this association remains unclear. The overall aim of this review was to critically appraise the evidence linking these two common disorders. Systematic search was conducted for studies published up to December 2018. Prevalence of hypertension in patients with PD (moderate/severe groups) vs. those without PD (non-PD) was the primary outcome. Additional outcomes included adjusted mean difference in systolic (SBP) and diastolic (DBP) blood pressure (BP) levels in PD vs. non-PD, assessment of biomarkers in PD and hypertension, and BP changes after periodontal therapy. From 81 studies selected, 40 were included in quantitative meta-analyses. Diagnoses of moderate-severe PD [odds ratio (OR) = 1.22; 95% confidence interval (CI): 1.10–1.35] and severe PD (OR = 1.49; 95% CI: 1.09–2.05) were associated with hypertension. Prospective studies confirmed PD diagnosis increased likelihood of hypertension occurrence (OR = 1.68; 95% CI: 0.85–3.35). Patients with PD exhibited higher mean SBP [weighted mean difference (WMD) of 4.49 mmHg; 95% CI: 2.88–6.11] and DBP (2.03 mmHg; 95% CI: 1.25–2.81) when compared with non-PD. Lastly, only 5 out of 12 interventional studies confirmed a reduction in BP following periodontal therapy, ranging from 3 to 12.5 mmHg of SBP and from 0 to 10 mmHg of DBP. PD is associated with increased odds of hypertension (SORT C) and higher SBP/DBP levels. The evidence suggesting that PD therapy could reduce BP is inconclusive. Although additional research is warranted on this association, these results suggest that oral health assessment and management of PD could not only improve oral/overall health and quality of life but also be of relevance in the management of patients with hypertension.

Objective: The primary objective was to investigate the relationship between periodontitis and hypertension in two independent large surveys. The secondary objective was to ascertain whether systemic inflammation had a mediation effect in the association.Methods: This cross‐sectional study analysed representative samples of the US (n = 3460; NHANES 2009/10) and Korean (n = 4539; 2015 KNHANES VI‐3) populations. The association between periodontitis (exposure), hypertension (outcome) and inflammatory markers [C‐reactive protein (CRP) and white blood cell counts (WBC)] (mediators) was assessed using multivariate linear and logistic regression models and mediation analysis.Results: Participants with periodontitis were more likely to have hypertension (NHANES: OR = 1.3, 95% CI: 1.0–1.6, P = 0.025; KNHANES: OR = 1.2, 95% CI: 1.0–1.4, P = 0.041) and actual systolic blood pressure ≥ 140 mmHg (NHANES: OR = 1.6, 95% CI: 1.1–2.3, P < 0.001; KNHANES: OR = 1.3, 95% CI :1.0–1.6, P < 0.031) than those without the disease. These associations were independent of age, gender, BMI, education level, smoking, alcohol consumption, creatinine, physical activity, presence of other comorbidities and confirmed in participants not taking antihypertensive medications. Diagnosis of periodontitis was directly associated with WBC (in both surveys: NHANES: β ± SE = 0.3 ± 0.1, P < 0.004; KNHANES: β ± SE = 0.3 ± 0.1, P < 0.001) and with CRP levels (in one survey: NHANES: β ± SE = 0.1 ± 0.03, P < 0.007; KNHANES: β ± SE = 0.1 ± 0.04, P > 0.213). Mediation analyses confirmed that CRP acted as a mediator in the association between periodontitis and hypertension in both populations (mediated effect: NHANES: β ± SE = 0.010 ± 0.003, P < 0.001; KNHANES: β ± SE = 0.003 ± 0.001, P = 0.015). WBC acted as a mediator in the KNHANES (mediated effect: β ± SE = 0.004 ± 0.001, P = 0.004) whilst in the NHANES, its effect was dependent of CRP inclusion in the model (mediated effect WBC + CRP: β ± SE = 0.002 ± 0.001, P = 0.001).Conclusions: These findings suggest that periodontitis is closely linked to hypertension and systemic inflammation is, in part, a mediator of this association.