High-dose atorvastatin reduces periodontal inflammation: a novel pleiotropic effect of statins

The effect of statin therapy on plaque regression following acute coronary syndrome: a meta-analysis of prospective trials

OBJECTIVE

To investigate the effect of statins on plaque regression after acute coronary syndrome (ACS).

METHODS

We carried out a meta-analysis to assess the change in plaque and plaque components in patients with ACS under statin therapy. This meta-analysis combined data of 1623 participants from eight randomized-controlled trials and seven observational studies.

RESULTS

The benefits of high-intensity statin therapy on plaque regression occurred after 6 months [standardized mean difference (SMD): -0.27; 95% confidence interval (CI): -0.43 to -0.12; P=0.0006] and were sustained over 12 months (SMD: -0.14; 95% CI: -0.25 to -0.03; P=0.01). No significant decrease was observed in the plaque volume and percent plaque volume under low-dose statin treatment. After 6 months of intensive statin treatment, the plaque volume reduced significantly in patients whose follow-up LDL cholesterol levels did (SMD: -0.16; 95% CI: -0.29 to -0.03; P=0.02) or did not (SMD: -0.21; 95% CI: -0.32 to -0.09; P=0.0007) decrease to 70 mg/dl or less. There was no significant change in plaque composition volumes, but an increase was found in the percent dense calcium volume of 1.31% (95% CI: 0.55-2.07%; P=0.0007).

CONCLUSION

Intensive statin therapy duration over 6 months may be as important as achieved LDL-C of less than or equal to 70 mg/dl in plaque regression following ACS. Intensive statin treatment may lead to an earlier regression compared with low-dose statin therapy.

Bacteriostatic Effect of Simvastatin on Selected Oral Streptococci in Vitro

CONTEXT AND OBJECTIVE

Simvastatin is a widely used cholesterol-lowering drug, which has been found to have a number of pleiotropic effects. The aim of this study was to evaluate the antimicrobial effectiveness of simvastatin against selected oral streptococci as determined by the minimum inhibitory concentration (MIC).

METHODS

Streptococcus mutans, Streptococcus sanguis, Streptococcus anginosus, and Streptococcus salivarius were the test microorganisms. The serial dilution method was used to determine the MIC of simvastatin against these organisms. The MIC was defined as the lowest concentration of simvastatin that completely inhibited growth of the test organisms.

RESULTS

The data indicate that simvastatin inhibits the growth of the test organisms, with MIC's ranging from 7.8 to 15.6 μg/ml.

CONCLUSIONS

Simvastatin has MIC's against the selected bacteria that compare favorably with reported values for topical agents such as essential oil, chlorhexidine gluconate, and triclosan. The levels of simvastatin required to inhibit bacterial growth of oral bacteria exceed the reported levels of the drug found in plasma or crevicular fluid of patients who are treated with this cholesterol-lowering drug. However, clinical studies are warranted to investigate the potential use of simvastatin as a novel antiplaque agent that could be used in local drug delivery to the oral cavity of those patients who are prescribed this cholesterol-lowering drug.

PET Imaging of Atherosclerotic Disease: Advancing Plaque Assessment from Anatomy to Pathophysiology

Atherosclerosis is a leading cause of morbidity and mortality. It is now widely recognized that the disease is more than simply a flow-limiting process and that the atheromatous plaque represents a nidus for inflammation with a consequent risk of plaque rupture and atherothrombosis, leading to myocardial infarction or stroke. However, widely used conventional clinical imaging techniques remain anatomically focused, assessing only the degree of arterial stenosis caused by plaques. Positron emission tomography (PET) has allowed the metabolic processes within the plaque to be detected and quantified directly. The increasing armory of radiotracers has facilitated the imaging of distinct metabolic aspects of atherogenesis and plaque destabilization, including macrophage-mediated inflammatory change, hypoxia, and microcalcification. This imaging modality has not only furthered our understanding of the disease process in vivo with new insights into mechanisms but has also been utilized as a non-invasive endpoint measure in the development of novel treatments for atherosclerotic disease. This review provides grounding in the principles of PET imaging of atherosclerosis, the radioligands in use and in development, its research and clinical applications, and future developments for the field.

The Oral Microbiome in Health and Its Implication in Oral and Systemic Diseases

The oral microbiome can alter the balance between health and disease, locally and systemically. Within the oral cavity, bacteria, archaea, fungi, protozoa, and viruses may all be found, each having a particular role, but strongly interacting with each other and with the host, in sickness or in health. A description on how colonization occurs and how the oral microbiome dynamically evolves throughout the host's life is given. In this chapter the authors also address oral and nonoral conditions in which oral microorganisms may play a role in the etiology and progression, presenting the up-to-date knowledge on oral dysbiosis as well as the known underlying pathophysiologic mechanisms involving oral microorganisms in each condition. In oral pathology, oral microorganisms are associated with several diseases, namely dental caries, periodontal diseases, endodontic infections, and also oral cancer. In systemic diseases, nonoral infections, adverse pregnancy outcomes, cardiovascular diseases, and diabetes are among the most prevalent pathologies linked with oral cavity microorganisms. The knowledge on how colonization occurs, how oral microbiome coevolves with the host, and how oral microorganisms interact with each other may be a key factor to understand diseases etiology and progression.

Statin intake is associated with MMP-1 level in gingival crevicular fluid of patients with periodontitis

BACKGROUND

This study was conducted to assess whether statin intake is associated with clinical parameters of periodontitis and matrix metalloproteinase (MMP) levels in gingival crevicular fluid (GCF) of non-diabetic and diabetic patients.

METHODS

We first determined the effect of simvastatin on MMP expression in mononuclear cells. We then recruited 117 non-diabetic and diabetic patients, who all had periodontitis and took or did not take statin, and measured periodontal probing depth (PPD) and clinical attachment level (CAL), and collected gingival crevicular fluid (GCF) to quantify MMPs.

RESULTS

The in vitro studies showed that simvastatin potently inhibited the expression of MMP-1, MMP-8, and MMP-9 upregulated by lipopolysaccharide (LPS) and high glucose in mononuclear cells. The patient study showed that, after adjusting for age and smoking status, PPD in diabetic patients on statin was significantly less than that in diabetic patients not on statin. MMP-1 level in GCF of non-diabetic and diabetic patients on statin was lower than that of non-diabetic and diabetic patients not on statin, respectively. No difference was found for MMP-8 and -9 levels in GCF.

CONCLUSION

Statin intake is associated with reduced PPD in diabetic patients and MMP-1 level in GCF in either non-diabetic or diabetic patients.

Recent advances in host defense mechanisms/therapies against oral infectious diseases and consequences for systemic disease

The innate and adaptive immune systems are both crucial to oral disease mechanisms and their impact on systemic health status. Greater understanding of these interrelationships will yield opportunities to identify new therapeutic targets to modulate disease processes and/or increase host resistance to infectious or inflammatory insult. The topics addressed reflect the latest advances in our knowledge of the role of innate and adaptive immune systems and inflammatory mechanisms in infectious diseases affecting the oral cavity, including periodontitis and candidiasis. In addition, several potential links with systemic inflammatory conditions, such as cardiovascular disease, are explored. The findings elucidate some of the defense mechanisms utilized by host tissues, including the role of IL-17 in providing immunity to oral candidiasis, the antimicrobial defense of mucosal epithelial cells, and the pro-resolution effects of the natural inflammatory regulators, proresolvins and lipoxins. They also describe the role of immune cells in mediating pathologic bone resorption in periodontal disease. These insights highlight the potential for therapeutic benefit of immunomodulatory interventions that bolster or modulate host defense mechanisms in both oral and systemic disease. Among the promising new therapeutic approaches discussed here are epithelial cell gene therapy, passive immunization against immune cell targets, and the use of proresolvin agents.

Statin use associated with a reduced risk of pneumonia requiring hospitalization in patients with myocardial infarction: a nested case-control study

BACKGROUND

Statins have been reported to prevent adverse cardiovascular events in patients with myocardial infarction (MI). However, the association of statin use and the risk of pneumonia requiring hospitalization in MI patients remains unclear.

METHODS

A nested case-control study was conducted by using data from the National Health Insurance Research Database of Taiwan. Among 24,975 patients with MI, 2686 case patients with pneumonia requiring hospitalization were age- and sex-matched with 10,726 control patients using the incidence density sampling approach. Duration and dosage of statin use were obtained from pharmaceutical claims. Conditional logistic regression analyses were used to estimate the risk of hospitalization for pneumonia associated with statin use adjusted for patient's demographics, medical conditions and prescribed medications.

RESULTS

Statin use was associated with a 15% reduced risk of pneumonia requiring hospitalization among MI patients (adjusted odds ratio [aOR] = 0.85, 95% confidence interval [CI] = 0.77-0.95, P = 0.004). The association was more significant for MI patients unexposed to statin pretreatment (aOR = 0.76, 95% CI = 0.64-0.90, P = 0.001). Statins also exhibited favorable benefits in a time- and dose-dependent manner. The results were consistent in various subgroup analysis of the patients who were female, age ≥ 65 years, a low CHADS2 (i.e. congestive heart failure, hypertension, diabetes mellitus, previous stroke and age > 75 years old) score, and fewer comorbidities. Atorvastatin, fluvastatin and simvastatin were the most common prescribed statins and had similar effects.

CONCLUSIONS

Statins might be considered as an adjunctive therapy to reduce the risk of hospitalization for pneumonia for MI patients under thorough evaluation of individual comorbidities, previous statin use and optimal dosage.

Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM) on PET imaging of atherosclerosis

Cardiovascular diseases are the leading cause of death not only in Europe but also in the rest of the World. Preventive measures, however, often fail and cardiovascular disease may manifest as an acute coronary syndrome, stroke or even sudden death after years of silent progression. Thus, there is a considerable need for innovative diagnostic and therapeutic approaches to improve the quality of care and limit the burden of cardiovascular diseases. During the past 10 years, several retrospective and prospective clinical studies have been published using ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to quantify inflammation in atherosclerotic plaques. However, the current variety of imaging protocols used for vascular (arterial) imaging with FDG PET considerably limits the ability to compare results between studies and to build large multicentre imaging registries. Based on the existing literature and the experience of the Members of the European Association of Nuclear Medicine (EANM) Cardiovascular Committee, the objective of this position paper was to propose optimized and standardized protocols for imaging and interpretation of PET scans in atherosclerosis. These recommendations do not, however, replace the individual responsibility of healthcare professionals to make appropriate decisions in the circumstances of the individual study protocols used and the individual patient, in consultation with the patient and, where appropriate and necessary, the patient’s guardian or carer. These recommendations suffer from the absence of conclusive evidence on many of the recommendations. Therefore, they are not intended and should not be used as "strict guidelines" but should, as already mentioned, provide a basis for standardized clinical atherosclerosis PET imaging protocols, which are subject to further and continuing evaluation and improvement. However, this EANM position paper might indeed be a first step towards "official" guidelines on atherosclerosis imaging with PET.

Lipid-lowering agents use and systemic and oral inflammation in overweight or obese adult Puerto Ricans: the San Juan Overweight Adults Longitudinal Study (SOALS)

The effects of lipid-lowering agents (LLA) on reducing systemic and oral inflammation have not been evaluated.

OBJECTIVE

To assess the association of LLA use with high-sensitivity C-reactive protein (hs-CRP) and oral inflammation.

DESIGN

Cross-sectional analysis using baseline data from 1300 overweight/obese participants aged 40-65 years, recruited for the ongoing San Juan Overweight Adults Longitudinal Study. Serum hs-CRP was measured by ELISA, gingival/periodontal inflammation was evaluated as bleeding upon probing (BOP), and LLA was self-reported. Separate logistic models were performed for systemic and oral inflammation.

RESULTS

In all, 24% participants reported history of dyslipidaemia, of which, 50.3% self-reported LLA use. Sixty percent of the participants had elevated hs-CRP (>3 mg/dl) and 50% had high BOP (defined as at or above the median: 21%). After adjusting for age, gender, smoking, HDL-C, physical activity, diabetes, blood pressure medications, and percent body fat composition, LLA users had significantly lower odds of elevated hs-CRP compared to LLA non-users (OR = 0.58; 95% CI: 0.39-0.85). After adjusting for age, gender, smoking status, educational level, mean plaque index and percent body fat, LLA users had significantly lower odds of high BOP compared to LLA non-users (OR = 0.62; 95% CI: 0.42-0.91).

CONCLUSIONS

Lipid-lowering agents may reduce both systemic and oral inflammatory responses.

Comparison of Frequency and Duration of Periodontal Disease With Progression of Coronary Artery Calcium in Patients With and Without Type 1 Diabetes Mellitus

People with type 1 diabetes mellitus manifest a greater burden of both periodontal disease and coronary artery disease (CAD); however, little is known about their interrelation. Coronary artery calcium (CAC) measures subclinical atherosclerosis and predicts major adverse coronary events. The relation between periodontal disease and CAC progression in individuals with type 1 diabetes has not been previously described. We determined the prevalence and progression of CAC in relation to self-reported periodontal disease. Multivariate logistic and tobit regression models were used to examine the relation between periodontal disease duration and CAC progression and whether this relation differs by diabetes status after controlling for age, gender, total and high-density lipoprotein cholesterol, hypertension, smoking, body mass index (BMI), duration of diabetes, and baseline CAC. A total of 473 patients with type 1 diabetes and 548 without diabetes were followed for a mean of 6.1 years. At baseline, the prevalence and duration of periodontal disease did not differ between subjects with and without diabetes (14.5% vs 13.4%, p = 0.60; 6 vs 9 years, p = 0.18). Duration of periodontal disease was not significantly associated with baseline CAC prevalence. In patients with type 1 diabetes, periodontal disease duration was significantly related to CAC progression (p = 0.004) but not in subjects without diabetes (p = 0.63). In conclusion, this study suggests that periodontal disease is an independent predictor of long-term progression of CAC in patients with type 1 diabetes.

Simvastatin protects Sertoli cells against cisplatin cytotoxicity through enhanced gap junction intercellular communication

Cisplatin, an important chemotherapeutic agent against testicular germ cell cancer, induces testicular toxicity on Leydig and Sertoli cells, leading to serious side-effects such as azoospermia and infertility. In a previous study, it was found that simvastatin enhanced the sensitivity of Leydig tumor cells to chemotherapeutic toxicity through the enhancement of gap junction functions. In the present study, the effect of simvastatin on the sensitivity of normal Sertoli cells to cisplatin and the role of gap junctions in such effects was investigated. The results showed that, simvastatin attenuated cisplatin toxicity only when cells exhibited high-density culture where gap junctional formation was possible. When gap junction function was decreased by the gap junction inhibitor or by siRNA targeting connexin 43, the protective effect of simvastatin to cisplatin toxicity was substantially attenuated. Simvastatin also enhanced gap junction functions between Sertoli cells. This effect was mediated by the reduction of PKC-mediated connexin phosphorylation, thereby increasing connexin 43 membrane localization. Thus, simvastatin-induced enhancement of gap junction‑mediated intercellular communication attenuated cisplatin toxicity on Sertoli cells. This result indicated that enhancement of gap junction function by simvastatin may have bilateral beneficial effects on cisplatin‑based chemotherapy, enhancing cisplatin killing on cancer while ameliorating the reproduction toxicity.

The Effects of Statins on Infections after Stroke or Transient Ischemic Attack: A Meta-Analysis

Background

Previous studies have reported that statins can prevent infections, and these findings were ascribed to the anti-inflammatory and immunomodulatory properties of statins. However, the effects of statins on the risk of infection after stroke or transient ischemic attack (TIA) remain controversial. The aim of this study was to evaluate the relationship between statins and the risk of infection after stroke or TIA by means of a meta-analysis.

Methodology and Findings

Studies were found by searching major electronic databases using key terms and restricting the results to studies published in English language and human studies. Pooled odds ratio (OR) for the association between infection and statins were analyzed using Stata software. A total of five studies that included 8,791 stroke or TIA patients (3,269 patients in the statin use group and 5,522 in the placebo group) were eligible and abstracted. Pooled analysis demonstrated that statins did not significantly affect the incidence of infection after stroke or TIA compared with a placebo (OR 0.819, 95% CI 0.582–1.151, I² = 64.2%, p= 0.025). Sensitivity analyses showed that the removal of any single study did not significantly affect the pooled OR. Cumulative meta-analysis showed that the incidence of infection did not vary by publication year. No statistical evidence of publication bias was found among the studies selected, based on the results of Egger’s (p = 1.000) and Begg’s (p = 0.762) tests.

Conclusions

This meta-analysis does not support the hypothesis that statins reduce the risk of infections in stroke or TIA patients.

Oral infections and cardiovascular disease

Oral infections are the most common diseases of mankind. Numerous reports have implicated oral infections, particularly periodontitis, as a risk factor for atherosclerotic cardiovascular disease (CVD). In this review we examine the epidemiology and biologic plausibility of this association with an emphasis on oral bacteria and inflammation. Longitudinal studies of incident cardiovascular events clearly show excess risk for CVD in individuals with periodontitis. It is likely that systemic exposure to oral bacteria impacts upon the initiation and progression of CVD through triggering of inflammatory processes. Given the high prevalence of periodontitis, any risk attributable to future CVD is important to public health. Unraveling the role of the oral microbiome in CVD will lead to new preventive and treatment approaches.

Pleiotropic effects of statins on the treatment of chronic periodontitis--a systematic review

AIM

Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase and are an important group of hypolipidaemic drugs, widely used in the treatment of hypercholesterolaemia and cardiovascular disease. Some studies have shown that statins are able to modulate inflammation and alveolar bone loss.

METHODS

In order to evaluate whether statins could influence periodontal treatment, improving the clinical and radiographic parameters in chronic periodontitis, a systematic review was conducted in the databases PUBMED and BIREME, searching for articles in English and Portuguese, published between the years 2004 and 2014, using the combined keywords statin, periodontal disease, periodontitis and alveolar bone. Studies regarding the treatment of chronic periodontitis in humans, blind or double-blind, retrospective cohort or randomized controlled trials that used statins topically or systemically were selected.

RESULTS

Statins have important anti-inflammatory and immune effects, reducing levels of C-reactive protein and matrix metalloproteinases and their intermediate products, such as tumour necrosis factor-α, and are also able to inhibit the adhesion and extravasation of leukocytes, which block the co-stimulation of T cells. Statins reduce bone resorption by inhibiting osteoclast formation and lead to increased apoptosis of these cells. The effect of statins on bone formation is related to the increased gene expression of bone morphogenetic protein in osteoblasts.

CONCLUSION

Although we found biological mechanisms and clinical results that show lower alveolar bone loss and reduction of clinical signs of inflammation, further studies are needed to evaluate the clinical applicability of statins in the routine treatment of chronic periodontitis.

Assessment of atherosclerosis in large vessel walls: A comprehensive review of FDG-PET/CT image acquisition protocols and methods for uptake quantification

There is growing evidence showing the importance of fluorodeoxyglucose positron emission tomography (FDG-PET) in the evaluation of vessel wall inflammation and atherosclerosis. Although this imaging modality has been increasingly used, there are various methods for image acquisition and evaluating FDG uptake activity in the vessel walls and atherosclerotic lesions, including qualitative visual scaling, semi-quantitative, and quantitative evaluations. Using each of these image acquisition protocols and measurement methods may result in different findings. In this review, we are going to describe the various image acquisition methods and common measurement strategies reflected in the literature and discuss their advantages and flaws.

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.

Resolvin E1 (RvE1) Attenuates Atherosclerotic Plaque Formation in Diet and Inflammation-Induced Atherogenesis

OBJECTIVE

Epidemiological and recent clinical studies implicate periodontitis as an independent risk factor for cardiovascular disease. Previously, we demonstrated that rabbits with experimental periodontitis and cholesterol diet exhibit more aortic plaque compared with diet alone. We also showed that a proresolution mediator, Resolvin E1 (RvE1), reverses the experimental periodontitis. Here, we determined whether oral/topical application of RvE1 attenuates aortic atherosclerosis induced by both diet and periodontal inflammation.

APPROACH AND RESULTS

Thirty-nine rabbits on a 13-week regimen of 0.5% cholesterol diet were included. Periodontitis was induced by Porphyromonas gingivalis in 24 rabbits and 15 rabbits were placed in no-periodontitis groups. Interventions were no-treatment, vehicle, and RvE1 treatment (4 μg/site or 0.4 μg/site) topically applied 3× per week. At 13 weeks, both periodontitis and atherosclerosis were quantified. Atherosclerotic plaques were assessed by Sudan IV staining, histology, and ex vivo MRI. Serum levels of C-reactive protein were evaluated as a measure of systemic inflammation. RvE1, used as an oral/topical agent, significantly diminished atherogenesis and prevented periodontitis (P<0.05). In the absence of periodontal inflammation, oral/topical application of RvE1 resulted in significantly less arterial plaque, a lower intima/media ratio, and decreased inflammatory cell infiltration compared with no-treatment (P<0.001). Local oral RvE1 application significantly reduced systemic levels of C-reactive protein (P<0.05).

CONCLUSIONS

The results suggest that oral/topical RvE1 attenuates enhanced atherogenesis induced by periodontitis and prevents vascular inflammation and atherogenesis in the absence of periodontitis. The inhibition of vascular inflammation with endogenous mediators of resolution of inflammation provides a novel approach in the prevention of atherogenic events.

Oral Infections, Metabolic Inflammation, Genetics, and Cardiometabolic Diseases

Although several epidemiologic studies reported plausible and potentially causal associations between oral infections and cardiometabolic diseases (CMDs), controversy still lingers. This might be due to unrecognized confounding from metabolic inflammation and genetics, both of which alter the immune responses of the host. Low-grade inflammation termed metainflammation is the hallmark of obesity, insulin resistance, type 2 diabetes, and CMDs. According to the common soil theory, the continuum of obesity to CMDs is the same pathology at different time points, and early metainflammations, such as hyperglycemia and obesity, display many adverse cardiometabolic characteristics. Consequently, adipose tissue is now considered a dynamic endocrine organ that expresses many proinflammatory cytokines such as TNF-α, IL-6, plasminogen activator inhibitor 1, and IL-1β. In metainflammation, IL-1β and reactive oxygen species are generated, and IL-1β is a pivotal molecule in the pathogenesis of CMDs. Note that the same cytokines expressed in metainflammation are also reported in oral infections. In metabolic inflammation and oral infections, the innate immune system is activated through pattern recognition receptors-which include transmembrane receptors such as toll-like receptors (TLRs), cytosolic receptors such as nucleotide-binding oligomerization domain-like receptors, and multiprotein complexes called inflammasome. In general, TLR-2s are presumed to recognize lipoteichoic acid of Gram-positive microbes-and TLR-4s, lipopolysaccharide of Gram-negative microbes-while nucleotide-binding oligomerization domain-like receptors detect both Gram-positive and Gram-negative peptidoglycans on the bacterial cell walls. However, a high-fat diet activates TLR-2s, and obesity activates TLR-4s and induces spontaneous increases in serum lipopolysaccharide levels (metabolic endotoxemia). Moreover, genetics controls lipid-related transcriptome and the differentiation of monocyte and macrophages. Additionally, genetics influences CMDs, and this creates a confounding relationship among oral infections, metainflammation, and genetics. Therefore, future studies must elucidate whether oral infections can increase the risk of CMDs independent of the aforementioned confounding factors.

PET imaging of atherosclerosis

ABSTRACT 

Atherosclerosis is a chronic, progressive, multifocal disease of the arterial wall, which is mainly fuelled by local and systemic inflammation, often resulting in acute ischemic events following plaque rupture and vessel occlusion. When assessing the cardiovascular risk of an individual patient, we must consider both global measures of disease activity and local features of plaque vulnerability, in addition to anatomical distribution and degree of established atherosclerosis. These parameters cannot be measured with conventional anatomical imaging techniques alone, which are designed primarily to identify the presence of organic intraluminal obstruction in symptomatic patients. However, molecular imaging with PET, using specifically targeted radiolabeled probes to track active in vivo atherosclerotic mechanisms noninvasively, may potentially provide a method that is better suited for this purpose. Vascular PET imaging can help us to further understand aspects of plaque biology, and current evidence supports a future role as an emerging clinical tool for the quantification of cardiovascular risk in order to guide and monitor responses to antiatherosclerosis treatments and to distinguish high-risk plaques.

Noninvasive imaging of arterial inflammation using FDG-PET/CT

PURPOSE OF REVIEW

Noninvasive imaging of atherosclerotic plaques has substantially advanced over the past decade such that currently available imaging techniques allow for characterization of high-risk morphological features of the plaques and quantification of the biological activity within the atherosclerotic milieu. Vascular PET/CT imaging provides insights into the biological activity of atherosclerotic plaques and, in particular, plaque inflammation. Fluoro-deoxyglucose-PET/CT imaging is currently used to improve the understanding of atherosclerotic pathophysiology, facilitate the discovery of new treatments and improve clinical prognostication in humans.

RECENT FINDINGS

Several studies have evaluated the feasibility, validity and reproducibility of fluoro-deoxyglucose-PET/CT for imaging of atherosclerotic plaque inflammation. Fluoro-deoxyglucose-PET/CT imaging is demonstrated to have the potential to predict the efficacy of novel antiatherosclerotic therapeutics by using a relatively small sample size and within a relatively short time period in several multicenter trials.

SUMMARY

The currently feasible assessment of inflammation within the atherosclerotic plaques has been demonstrated to enhance assessment of clinical risk, provide a better understanding of therapeutic efficacy of novel drugs, and it may provide a window into inflammation within the coronary tree. Further technological advances in PET technology have the potential to catalyze further progress in imaging of atherosclerotic plaque biology.

Statins and alveolar bone resorption: a narrative review of preclinical and clinical studies

CONTEXT

Tooth extraction and periodontal disease are both common clinical situations associated with alveolar bone loss.

OBJECTIVE

To analyze the reported results of in vivo studies investigating the effectiveness of statins to reduce alveolar bone resorption.

STUDY DESIGN

Systematic electronic search of the MEDLINE-PubMed database.

RESULTS

A total of 21 studies met the inclusion criteria. This review showed that the use of statins reduced significantly alveolar bone resorption observed during periodontal disease and after tooth extraction. Oral administration was effective using high statin concentrations, although local administration using a biodegradable carrier was effective with lower concentrations. It was recently reported that statins were effective to reduce alveolar bone loss as an adjunct to scaling and root planing (SRP) in several clinical trials. Further studies are needed to confirm these promising results.

Novel applications of statins for bone regeneration

The use of statins for bone regeneration is a promising and growing area of research. Statins, originally developed to treat high cholesterol, are inhibitors of the enzyme 3-hydroxy-3-methylglutaryl, the rate-limiting enzyme of the mevalonate pathway. Because the mevalonate pathway is responsible for the synthesis of a wide variety of important biochemical molecules, including cholesterol and other isoprenoids, the effects of statins are pleiotropic. In particular, statins can greatly affect the process of bone turnover and regeneration via effects on important cell types, including mesenchymal stem cells, osteoblasts, endothelial cells, and osteoclasts. Statins have also been shown to have anti-inflammatory and antimicrobial properties that may be useful since infection can derail normal bone healing. This review will explore the pleiotropic effects of statins, discuss the current use of statins for bone regeneration, particularly with regard to biomaterials-based controlled delivery, and offer perspectives on the challenges and future directions of this emerging area of bone tissue engineering.

Predictive value of neutrophil to lymphocyte ratio for the presence of coronary artery ectasia in patients with aortic aneurysms

Background

Both aortic aneurysms and coronary artery ectasia (CAE) frequently coexist and are associated with more pronounced inflammation. Neutrophil to lymphocyte ratio (NL ratio) is widely used as a marker of inflammation. However, relation between CAE and NL ratio in patients with aortic aneurysms is not fully understood. This study was undertaken to assess relation between CAE and NL ratio in patients with aortic aneurysms.

Methods

This study consisted of 93 consecutive patients with aortic aneurysms (AA group) and 79 patients without aortic aneurysms who had angiographically normal coronary arteries as the control group. Moreover, patients with aortic aneurysms were classified into two groups based on the presence of CAE; CAE (+) group (n = 44) and CAE (−) group (n = 49). We compared blood chemical parameters in both groups.

Results

In the AA group, 44 patients (47.3%) had CAE. The AA group had a significantly higher NL ratio than the control group (2.93 ± 1.43 vs. 2.45 ± 1.05, p = 0.027). Furthermore, the CAE (+) group had a significantly higher NL ratio than the CAE (−) group (3.39 ± 1.67 vs. 2.52 ± 1.04, p < 0.01). Multivariate logistic regression analysis revealed that the high NL ratio was an independent predictor for CAE in patients with aortic aneurysms (odds ratio 1.76, 95% confidence interval 1.24–2.69, p = 0.001).

Conclusions

Patients with aortic aneurysms had a significantly higher NL ratio than those without aortic aneurysms. Furthermore, the NL ratio might predict the presence of CAE in patients with aortic aneurysms.

The pharmacology of statins

Statins, inhibitors of the hydroxymethylglutaryl-CoA (HMG-CoA) reductase enzyme, are molecules of fungal origin. By inhibiting a key step in the sterol biosynthetic pathway statins are powerful cholesterol lowering medications and have provided outstanding contributions to the prevention of cardiovascular disease. Their detection in mycetes traces back to close to 40 years ago: there were, originally, widely opposing views on their therapeutic potential. From then on, intensive pharmaceutical development has led to the final availability in the clinic of seven statin molecules, characterized by differences in bioavailability, lipo/hydrophilicity, cytochrome P-450 mediated metabolism and cellular transport mechanisms. These differences are reflected in their relative power (mg LDL-cholesterol reduction per mg dose) and possibly in parenchymal or muscular toxicities. The impact of the antagonism of statins on a crucial step of intermediary metabolism leads, in fact, both to a reduction of cholesterol biosynthesis as well as to additional pharmacodynamic (so called "pleiotropic") effects. In the face of an extraordinary clinical success, the emergence of some side effects, e.g. raised incidence of diabetes and cataracts as well as frequent muscular side effects, have led to increasing concern by physicians. However, also in view of the present relatively low cost of these drugs, their impact on daily therapy of vascular patients is unlikely to change.