Statins and periodontal inflammation: a pleiotropic effect of statins or a pleiotropic effect of LDL-cholesterol lowering?

Causal Association between Periodontal Diseases and Cardiovascular Diseases

Observational studies have revealed that dental diseases such as periodontitis and dental caries increase the risk of cardiovascular diseases (CVDs). However, the causality between periodontal disease (PD) and CVDs is still not clarified. In the present study, two-sample Mendelian randomization (MR) studies were carried out to assess the association between genetic liability for periodontal diseases (dental caries and periodontitis) and major CVDs, including coronary artery disease (CAD), heart failure (HF), atrial fibrillation (AF), and stroke—including ischemic stroke as well as its three main subtypes—based on large-scale genome-wide association studies (GWASs). Our two-sample MR analyses did not provide evidence for dental caries and periodontitis as the causes of cardiovascular diseases; sensitivity analyses, including MR–Egger analysis and weighted median analysis, also supported this result. Gene functional annotation and pathway enrichment analyses indicated the common pathophysiology between cardiovascular diseases and periodontal diseases. The associations from observational studies may be explained by shared risk factors and comorbidities instead of direct consequences. This also suggests that addressing the common risk factors—such as reducing obesity and improving glucose tolerance—could benefit both conditions.

Effects of atorvastatin on ADP-, arachidonic acid-, collagen-, and epinephrine-induced platelet aggregation

Objective

Atorvastatin reduces the incidence of cardiovascular events. However, the effects of atorvastatin on platelet aggregation are unknown.

Methods

Blood samples were obtained from 126 healthy volunteers. Prepared isolated platelet suspensions were adjusted with saline to three different concentrations of 100 × 10⁹, 300 × 10⁹, and 600 × 10⁹ platelets/L. Platelet samples were incubated with atorvastatin (10⁻⁷mol/L, 10⁻⁶mol/L or 10⁻⁵mol/L), and stimulated with ADP (10 µmol/L), arachidonic acid (0.5 mmol/L), collagen (2 µg/mL), and epinephrine (1 mg/mL). The maximal amplitude of aggregation and the curve slope were measured by electric impedance aggregometry.

Results

Atorvastatin inhibited platelet aggregation at moderate (300 × 10⁹/L) and high (600 × 10⁹/L) concentrations. However, an inhibitory effect of atorvastatin at low concentrations (100 × 10⁹/L) was not observed.

Conclusions

The study shows that atorvastatin inhibits platelet aggregation in vitro, and this inhibitory effect is related to platelet concentrations.

Interaction between periodontal disease and atherosclerotic vascular disease--Fact or fiction?

C-reactive protein (CRP) level is associated with the 10-year risk of an atherosclerotic vascular disease (ASVD), suggesting presence of systemic inflammation probably long before ASVD is present. Where, however, does this systemic inflammation come from? One active area of research has been the study of dental infection and various forms of periodontal disease (PD), both of which are highly prevalent in populations at risk for ASVD. Recent data show that ASVD and PD interact with each other via systemic release of specific pro- and anti-inflammatory cytokines, small signal molecules and enzymes which modulate initiation and progression of the chronic inflammatory reaction involved in both diseases. In addition, periodontal pathogens were identified within atherosclerotic lesions and thrombi isolated from myocardial infarction patients. LDL cholesterol, a strong risk factor for ASVD, is also associated with PD; and statins, used to treat ASVD, are also active to prevent or reduce PD. Finally, there is growing evidence for common genetic susceptibility factors involved in both diseases. These findings support commonalities with respect to the pathogenic mechanisms involved in both inflammatory diseases. Conversely, a causative relationship cannot yet be concluded in the absence of data from large longitudinal cohort and randomized controlled intervention trials.