HMG-CoA reductase inhibitor simvastatin profoundly improves survival in a murine model of sepsis

Statins do not improve short-term survival in an oriental population with sepsis

OBJECTIVES

The aim of this study was to define the effect of statin on 30-day mortality in an oriental population with sepsis.

DESIGN

We conducted a retrospective study on patients with sepsis at National Taiwan University Hospital from 2001 to 2002. The effects of statins on 30-day mortality were evaluated based on clinical settings. Log-rank test and Cox regression analysis were performed using the proportional hazards assumption.

RESULTS

A total of 763 episodes of sepsis were reviewed; 454 consecutive patients were considered eligible. Among them, 104 (22.9%) took a statin at least 30 days before admission and during sepsis course, whereas the other 350 control (77.1%) did not. There was no significant difference of 30-day sepsis-related mortality between groups (19.2% vs 18.9%, P = .952). Statin treatment was not associated with decreased mortality at 30 days (P = .853; risk ratio, 0.95; 95% confidence interval, 0.53-1.68).

CONCLUSION

Short-term, sepsis-related mortality in a septic Taiwanese population was not reduced with statin treatment in our study. We concluded that statin therapy may have little effect on the survival of sepsis in oriental people, particularly in Taiwanese.

The use of statins in intensive care unit patients with sepsis

The incidence of sepsis is increasing and remains the leading cause of death in critically ill patients. The statin group of drugs appear to have important anti-inflammatory effects and may have a role in the treatment of sepsis. However, current prescribing guidelines recommend that statin therapy is discontinued in critically ill patients. We found no evidence to support commencing statin therapy in patients with sepsis on an intensive care unit and low levels of evidence to support continuing established therapy in this patient population.

Statins and sepsis: multiple modifications at multiple levels

Sepsis, an infection-induced inflammatory syndrome, is a leading and increasing cause of mortality worldwide. Animal and human observational studies suggest statins may prevent the morbidity and mortality associated with the sepsis syndrome. In this Review, we describe the demonstrated mechanisms through which statins modulate the inflammatory response associated with sepsis. These mechanisms include effects on cell signalling with consequent changes at the transcriptional level, the induction of haem oxygenase, the direct alteration of leucocyte-endothelial cell interaction, and the reduced expression of MHC II. Since statins do not target individual inflammatory mediators, but possibly reduce the overall magnitude of the systemic response, this effect could prove an important distinguishing feature modulating the host response to septic insults. This work establishes the biological plausibility needed for future trials of statins in critical illness.

Statins and the risk of pneumonia: a population-based, nested case-control study

STUDY OBJECTIVE

To determine if the use of statins affects pneumonia-related outpatient visits, hospitalizations with survival, and deaths.

DESIGN

Population-based, retrospective, nested case-control analysis.

DATA SOURCE

United Kingdom-based General Practice Research Database.

PARTICIPANTS

The study population (134,262 patients aged > or = 30 yrs) consisted of 55,118 patients who took statins and/or fibrates, 29,144 patients with hyperlipidemia not taking lipid-lowering agents, and 50,000 randomly selected patients without hyperlipidemia and without lipid-lowering treatment.

MEASUREMENTS AND MAIN RESULTS

We identified 1253 patients with pneumonia and matched them with 4838 control subjects based on age, sex, general practice, and index date. After adjusting for comorbidity and frequency of visits to general practitioners, we calculated the risks (odds ratios with 95% confidence intervals) of uncomplicated pneumonia, hospitalization for pneumonia with survival, and fatal pneumonia in participants who used statins compared with those who did not. Current statin users had a significantly reduced risk of fatal pneumonia (adjusted odds ratio 0.47, 95% confidence interval 0.25-0.88) and slightly but not significantly reduced risks of uncomplicated pneumonia and pneumonia hospitalization with survival. Recent or past statin use and fibrate use at any time were not associated with a reduced risk of pneumonia.

CONCLUSION

Current use of statins was associated with a reduced risk of pneumonia. The risk reduction was particularly strong in the subgroup of patients with fatal pneumonias.

Treatment of severe sepsis: where next? Current and future treatment approaches after the introduction of drotrecogin alfa

Severely septic patients continue to experience excessive morbidity and mortality despite recent advances in critical care. Although significant resources have been invested in new treatments, almost all have failed to improve outcomes. An improved understanding of sepsis pathophysiology, including the complex interactions between inflammatory, coagulation, and fibrinolytic systems, has accelerated the development of novel treatments. Recombinant human activated protein C (rhAPC), or drotrecogin alfa (activated) (DAA), is currently the only US Food and Drug Administration (FDA)-approved medicine for the treatment of severe sepsis, and only in patients with a high risk of death. This review will discuss the treatment of severe sepsis, focusing on recent discoveries and unresolved questions about DAA's optimal use. Increasing pharmacological experience has generated enthusiasm for investigating medicines already approved for other indications as treatments for severe sepsis. Replacement doses of hydrocortisone and vasopressin may reduce mortality and improve hypotension, respectively, in a subgroup of patients with catecholamine-refractory septic shock. In addition to discussing these new indications, this review will detail the provocative preliminary data from four promising treatments, including two novel modalities: antagonizing high mobility group box protein and inhibiting tissue factor (TF). Observational data from the uncontrolled administration of heparin or statins in septic patients will also be reviewed.

Effectiveness of statins in reducing the rate of severe sepsis: a retrospective evaluation

STUDY OBJECTIVES

To determine whether use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) is associated with a reduced rate of severe sepsis, and to further characterize the effect of statins on the frequency of organ dysfunction in patients with severe sepsis.

DESIGN

Retrospective cohort study.

SETTING

University-associated teaching hospital.

PATIENTS

Fifty-three patients admitted with sepsis; 16 were receiving statins and 37 were not receiving statins (controls) before admission.

MEASUREMENTS AND MAIN RESULTS

Patients were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patient demographics, vital signs, and laboratory values were collected from their electronic medical records. The primary end point was rate of severe sepsis, defined in accordance with guidelines from the American College of Chest Physicians and the Society of Critical Care Medicine. Secondary end points were in-hospital mortality rate and rate of five categories of organ dysfunction (cardiovascular, renal, pulmonary, hematologic, and metabolic). Preadmission statin therapy, compared with no statin therapy, was associated with a 30% lower rate of severe sepsis (56% vs 86%, p<0.02). In-hospital mortality was not significantly different between groups (38% vs 49%, p=0.33); however, the rate of cardiovascular dysfunction, defined as hypotension requiring vasopressor therapy, was significantly lower in the statin group (38% vs 73%, p<0.02). No significant differences in the other organ dysfunction categories were noted between groups.

CONCLUSION

Statins appear to prevent sepsis from becoming severe, most notably through prevention of sepsis-induced hypotension. This potential role for statins in the prevention and treatment of severe sepsis should be further evaluated in a randomized controlled trial.

The effect of statin therapy on infection-related mortality in patients with atherosclerotic diseases

OBJECTIVE

Statins have pleiotropic effects that are independent of their lipid-lowering ability. We have previously shown that prior statin therapy is associated with a decreased risk of severe sepsis in patients admitted with acute bacterial infection. The aim of this study was to determine whether statin therapy is associated with a decreased risk of infection-related mortality.

DESIGN

A prospective, observational, population-based study.

SETTING

Tertiary university medical center.

PATIENTS

Using a computerized database, 11,490 patients with atherosclerotic diseases were identified and followed for up to 3 yrs. Two groups of patients were compared: those receiving statins in the final month before follow-up termination and those who were not.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was infection-related mortality. Of the 11,362 patients included in the final analysis, 5,698 (50.1%) belonged to the statin group. Median follow-up was 19.8 months (interquartile range, 14.3-33.3). The risk of infection-related mortality was significantly lower in the statin compared with the no-statin group (0.9% vs. 4.1%), reflecting a relative risk of 0.22 (95% confidence interval, 0.17-0.28). Stepwise Cox proportional hazard survival analysis including a propensity score for receiving statins revealed that the protective effect of statins adjusted for all known potential confounders remained highly significant (hazard ratio, 0.37; 95% confidence interval, 0.27-0.52).

CONCLUSIONS

Therapy with statins may be associated with a reduced risk of infection-related mortality. This protective effect is independent of all known comorbidities and dissipates when the medication is discontinued. If this finding is supported by prospective controlled trials, statins may play an important role in the primary prevention of infection-related mortality.

Beneficial effects of statins on the microcirculation during sepsis: the role of nitric oxide

This review describes the laboratory evidence and microvascular mechanisms responsible for the beneficial effects of statins in sepsis. During sepsis, changes occur within the microcirculation including alterations in arteriolar tone influencing blood pressure, adaptations to endothelial cell integrity causing leakage of proteins and macromolecules, and adhesion and migration of leucocytes through the vascular endothelium. Statins are widely used as cholesterol-lowering agents, but appear to have anti-inflammatory actions during sepsis. We have discussed the effects of statins on specific pathological processed within the microcirculation and focused on the role of nitric oxide (NO). The main mechanism by which statins appear to be an effective treatment for sepsis is increased expression of endothelial nitric oxide synthase (eNOS), in conjunction with down-regulation of inducible nitric oxide synthase. Combined, this results in an increase in physiological concentrations of NO, thus restoring endothelial function. Laboratory studies have therefore suggested that enhancement of eNOS activity during sepsis may lead to restoration of microvascular tone, maintenance of microvascular integrity, and inhibition of cell adhesion molecules. However, other mechanisms independent of lipid-lowering effects, including antioxidant activity and alterations in the development of vascular atherosclerosis, may also contribute to the beneficial effects of statins. We have also addressed the influence on the effects of statins of lipid solubility and pre- and pro-phylactic administration.

Simvastatin improves the healing of infected skin wounds of rats

PURPOSE: This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. METHODS: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. RESULTS: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 ìm²) than in saline (2120.0 ± 327.1 ìm²). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. CONCLUSION: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising.

Promising therapeutic agents for sepsis

The incidence of sepsis is expected to increase at a rate of 1.5% per year. Advances in our understanding of the sepsis syndrome have enabled researchers to identify new therapeutic targets and design therapies for existing mediators of sepsis. Drotrecogin alfa (activated) was the first biological treatment for serious sepsis approved by the Food and Drug Administration in 2001. There have also been promising research results involving ethyl pyruvate, glycogen synthase kinase-3 inhibitors and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Here, we review these four compounds and compound classes as examples of emerging pharmacological treatments of severe sepsis and describe the current status of sepsis research.

Statins in the intensive care unit

PURPOSE OF REVIEW

Statins are effective lipid-lowering agents used extensively in medical practice. This review summarizes the evidence for statin treatment of cardiovascular patients in the intensive care unit and briefly discusses the role of statins in prevention and treatment of sepsis as a potential future application of statins in critical care.

RECENT FINDINGS

Recent studies have extended the use of statin therapy to the acute manifestations of cardiovascular disease and have suggested cholesterol-independent therapeutic benefits, termed pleiotropic effects, which have added a wide scope of potential targets for statin therapy.

SUMMARY

Statin therapy should be continued in intensive-care patients in whom statin therapy is warranted due to underlying cardiovascular disease or significant risk thereof. In acute coronary syndromes, statin therapy should be initiated within 24-96 h regardless of pretreatment cholesterol levels. Patients undergoing vascular surgery should receive peri-operative statin therapy. Placebo-controlled clinical trials are required to consolidate the experimental and observational evidence for prevention and treatment of sepsis.

Treatment of plague: promising alternatives to antibiotics

Plague still poses a significant threat to human health, and interest has been renewed recently in the possible use of Yersinia pestis as a biological weapon by terrorists. The septicaemic and pneumonic forms are always lethal if untreated. Attempts to treat this deadly disease date back to the era of global pandemics, when various methods were explored. The successful isolation of the plague pathogen led to the beginning of more scientific approaches to the treatment and cure of plague. This subsequently led to specific antibiotic prophylaxis and therapy for Y. pestis. The use of antibiotics such as tetracycline and streptomycin for the treatment of plague has been embraced by the World Health Organization Expert Committee on Plague as the 'gold standard' treatment. However, concerns regarding the development of antibiotic-resistant Y. pestis strains have led to the exploration of alternatives to antibiotics. Several investigators have looked into the use of alternatives, such as immunotherapy, non-pathogen-specific immunomodulatory therapy, phage therapy, bacteriocin therapy, and treatment with inhibitors of virulence factors. The alternative therapies reported in this review should be further investigated by comprehensive studies of their clinical application for the treatment of plague.

Phosphorylation of endothelial nitric-oxide synthase is diminished in mesenteric arteries from septic rabbits depending on the altered phosphatidylinositol 3-kinase/Akt pathway: reversal effect of fluvastatin therapy

Endothelial dysfunction plays a crucial role in the pathophysiology of sepsis. Alterations in endothelial nitric-oxide synthase (eNOS) may contribute to the impaired endothelial function. We investigated whether the regulatory mechanism for eNOS phosphorylation and activation is altered in a rabbit lipopolysaccharide-induced septic model. Following induction of sepsis, a time-dependent marked reduction in eNOS phosphorylation was observed in mesenteric arteries, with a significant decrease in eNOS expression. Likewise, Akt phosphorylation was progressively and profoundly reduced, although total Akt remained unchanged. Furthermore, the amounts of the two subunits of phosphatidylinositol 3-kinase (PI3-K) in the membranous pool were diminished without changes in the total amount of the PI3-K heterodimer, indicating a decrease in translocation to the membranes. In vivo treatment with fluvastatin restored the decrease in eNOS phosphorylation in septic mesenteric vessels. This was possibly the result of the recovery of Akt phosphorylation. Treatment with the PI3-K inhibitor wortmannin partially inhibited the fluvastatin-induced increases in phosphorylation of Akt and eNOS, and the decrease in translocation of PI3-K heterodimer to the membranes during sepsis was slightly improved by fluvastatin. Sepsis-induced impairment of eNOS expression was also nearly normalized by fluvastatin. It is noteworthy that rabbits treated with fluvastatin exhibited a dramatic improvement in sepsis survival. The present results showed vascular abnormalities of the PI3-K/Akt pathway involved in the impairment of eNOS phosphorylation and activation in sepsis. We also suggest that fluvastatin would ameliorate vascular endothelial dysfunction, in part, presumably via its recovery effect on Akt-dependent eNOS phosphorylation. It may be potentially useful for therapy of sepsis.

Do statins have a role in preventing or treating sepsis?

Statins have a variety of properties that are independent of their lipid lowering ability. These anti-inflammatory, antioxidant, immunomodulatory, and antiapoptotic features have been collectively referred to as pleiotropic effects. Severe sepsis is an intense infection-induced inflammatory syndrome that ultimately results in organ dysfunction. Because so many cascades are triggered during sepsis, merely blocking a single component may be insufficient to arrest the inflammatory process. A growing body of evidence suggests that statins may indeed have a protective effect against severe sepsis and reduce the rate of infection-related mortality. This novel primary prevention concept may have far-reaching implications for the future management of serious infections. Moreover, it was recently shown that statins potentially improve outcome after the onset of sepsis. The stage is now set for randomized clinical trials that will determine the precise role, if any, that statins may have in preventing and treating sepsis.

Pandemic influenza: a potential role for statins in treatment and prophylaxis

The next influenza pandemic may be imminent. Because antiviral agents and vaccines will be unavailable to people in most countries, we need to determine whether other agents could offer clinical benefits. Influenza is associated with an increase in acute cardiovascular diseases, and influenza viruses induce proinflammatory cytokines. Statins are cardioprotective and have anti-inflammatory and immunomodulatory effects, and they thus might benefit patients with influenza. This hypothesis should be evaluated by using administrative databases to search for reduced rates of hospitalization and death due to influenza-related conditions among people taking statins. These studies should be followed by laboratory studies of statins in animal and cell-based models of influenza virus infection and, later, by clinical trials. Positive results from such studies would provide physicians in all countries with something to offer patients for treatment and prophylaxis of pandemic influenza. Generic statins will be widely distributed and inexpensive. They might be the only agents that could alter the course of a global pandemic.

Association of statin therapy and increased survival in patients with multiple organ dysfunction syndrome

OBJECTIVE

The multiple organ dysfunction syndrome (MODS) is the sequential failure of several organ systems after a trigger event, such as sepsis, pneumonia or cardiogenic shock. Even today, mortality is high. Statin therapy is associated with reduction of inflammation and subsequent rates of severe sepsis and ICU admission of patients admitted to hospital with presumed or documented acute bacterial infection. Our study aimed to characterize a potential survival benefit by statin therapy in MODS patients.

DESIGN

Retrospective cohort study.

SETTING

Twelve-bed medical intensive care unit in a university center.

PATIENTS

Forty score-defined MODS patients under statin treatment and 80 age- and sex-matched score-defined MODS patients without statin treatment. Inclusion criterion was an APACHE II score > or = 20 at admission to ICU.

INTERVENTIONS

Assessment of statin treatment and calculation of disease severity by scoring. The patients were followed up for 28-day mortality as well as for hospital mortality.

MEASUREMENTS AND RESULTS

The MODS severity was equally pronounced in both groups. There were 42/80 deaths in the group without statin treatment and 13/40 deaths in the statin group (28-day mortality 53% vs. 33%, p = 0.03). Cox proportional hazard analysis revealed a hazard ratio of 0.53 (95% CI 0.29-0.99, p = 0.04). Hospital mortality was calculated at 72% (non-statin group) vs. 35% (statin group; chi-square = 15.6, p < 0.0001). The overall hospital mortality was 60%.

CONCLUSIONS

Patients under statin treatment developing MODS might have a better outcome than patients without statin therapy, probably by reduction of inflammatory responses and increase of vagal activity in MODS.

Lovastatin enhances clearance of apoptotic cells (efferocytosis) with implications for chronic obstructive pulmonary disease

Statins are potent, cholesterol-lowering agents with newly appreciated, broad anti-inflammatory properties, largely based upon their ability to block the prenylation of Rho GTPases, including RhoA. Because phagocytosis of apoptotic cells (efferocytosis) is a pivotal regulator of inflammation, which is inhibited by RhoA, we sought to determine whether statins enhanced efferocytosis. The effect of lovastatin on efferocytosis was investigated in primary human macrophages, in the murine lung, and in human alveolar macrophages taken from patients with chronic obstructive pulmonary disease. In this study, we show that lovastatin increased efferocytosis in vitro in an 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase-dependent manner. Lovastatin acted by inhibiting both geranylgeranylation and farnesylation, and not by altering expression of key uptake receptors or by increasing binding of apoptotic cells to phagocytes. Lovastatin appeared to exert its positive effect on efferocytosis by inhibiting RhoA, because it 1) decreased membrane localization of RhoA, to a greater extent than Rac-1, and 2) prevented impaired efferocytosis by lysophosphatidic acid, a potent inducer of RhoA. Finally, lovastatin increased efferocytosis in the naive murine lung and ex vivo in chronic obstructive pulmonary disease alveolar macrophages in an HMG-CoA reductase-dependent manner. These findings indicate that statins enhance efferocytosis in vitro and in vivo, and suggest that they may play an important therapeutic role in diseases where efferocytosis is impaired and inflammation is dysregulated.

Statin use and mortality within 180 days after bacteremia: a population-based cohort study

OBJECTIVE

To examine the association between preadmission statin use and mortality among patients with bacteremia in a population-based setting.

DESIGN

Observational study based on prospective registration of bacteremia episodes and mortality over a 6-yr period.

SETTING

North Jutland County, Denmark (population, 500,000).

PATIENTS

A total of 5,353 adult patients hospitalized with bacteremia from 1997 to 2002. Individuals treated with statins (n = 176) were identified by record-linkage with the County Prescription Database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We compared mortality rates 0-30 and 31-180 days after bacteremia in patients with and without preadmission statin use, adjusted for gender, age group, level of comorbidity, alcohol-related conditions, use of immunosuppressive drugs and systemic antibiotics, and focus on infection. The 30-day mortality in statin users vs. nonusers was similar (20.0% vs. 21.6%, adjusted mortality rate ratio 0.93, 95% confidence interval 0.66-1.30). Among survivors after 30 days, however, statin therapy was associated with a substantially decreased mortality up until 180 days after the bacteremia (8.4% vs. 17.5%, adjusted mortality rate ratio 0.44, 95% confidence interval 0.24-0.80). This tendency toward similar short-term and decreased longer term mortality associated with statin use was observed consistently in both community-acquired and nosocomial bacteremia episodes and when analyses were restricted to patients with previous cardiovascular discharge diagnoses or diabetes.

CONCLUSIONS

This study provides evidence against the hypothesis that statin use has an effect on short-term mortality after bacteremia. Statin use was, however, associated with a substantially decreased mortality between 31 and 180 days after bacteremia.

Simvastatin improves sepsis-induced mortality and acute kidney injury via renal vascular effects

Acute kidney injury (AKI) occurs in about half of patients in septic shock and the mortality of AKI with sepsis is extremely high. An effective therapeutic intervention is urgently required. Statins are 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors that also have pleiotropic actions. They have been reported to increase the survival of septic or infectious patients. But the effect of simvastatin, a widely used statin, on sepsis-induced AKI is unknown. The effects of simvastatin and tumor necrosis factor (TNF)-alpha neutralizing antibody were studied in a clinically relevant model of sepsis-induced AKI using cecal ligation and puncture (CLP) in elderly mice. Simvastatin significantly improved CLP-induced mortality and AKI. Simvastatin attenuated CLP-induced tubular damage and reversed CLP-induced reduction of intrarenal microvascular perfusion and renal tubular hypoxia at 24 h. Simvastatin also restored towards normal CLP-induced renal vascular protein leak and serum TNF-alpha. Neither delayed simvastatin therapy nor TNF-alpha neutralizing antibody improved CLP-induced AKI. Simvastatin improved sepsis-induced AKI by direct effects on the renal vasculature, reversal of tubular hypoxia, and had a systemic anti-inflammatory effect.

Statins: panacea for sepsis?

Sepsis occurs when the immune system responds to a localised infection at a systemic level, thereby causing tissue damage and organ dysfunction. Statins have proven health benefits in many diseases involving vascular inflammation and injury. Recent animal data suggest that the administration of a statin before a sepsis-inducing insult reduces morbidity and improves survival. The immunomodulatory and anti-inflammatory effects of statins, collectively referred to as pleiotropic effects, lend biological plausibility to such findings. Limited human data hint at reduced mortality rates in bacteraemic patients, and a reduced risk of sepsis in patients with bacterial infections concurrently taking statins. These lines of evidence point to a potential new treatment and prevention modality for sepsis. The stage is set for randomised controlled clinical trials that will determine whether statins represent a safe and beneficial treatment in critically ill, septic patients and whether statins are effective at preventing sepsis in high-risk clinical settings.

Secretory phospholipase A2 of group IIA: Is it an offensive or a defensive player during atherosclerosis and other inflammatory diseases?

Since its discovery in the serum of patients with severe inflammation and in rheumatoid arthritic fluids, the secretory phospholipase A2 of group IIA (sPLA2-IIA) has been chiefly considered as a proinflammatory enzyme, the result of which has been very intense interest in selective inhibitors of sPLA2-IIA in the hope of developing new and efficient therapies for inflammatory diseases. The recent discovery of the antibacterial properties of sPLA2-IIA, however, has raised the question of whether the upregulation of sPLA2-IIA during inflammation is to be considered uniformly negative and the hindrance of sPLA2-IIA in every instance beneficial. The aim of this review is for this reason, along with the results of various investigations which argue for the proinflammatory and proatherogenic effects of an upregulation of sPLA2-IIA, also to array data alongside which point to a protective function of sPLA2-IIA during inflammation. Thus, it could be shown that sPLA2-IIA, apart from the bactericidal effects, possesses also antithrombotic properties and indeed plays a possible role in the resolution of inflammation and the accelerated clearance of oxidatively modified lipoproteins during inflammation via the liver and adrenals. Based on these multipotent properties the knowledge of the function of sPLA2-IIA during inflammation is a fundamental prerequisite for the development and establishment of new therapeutic strategies to prevent and treat severe inflammatory diseases up to and including sepsis.

Statins and sepsis in patients with cardiovascular disease: a population-based cohort analysis

BACKGROUND

Atherosclerosis and sepsis share several pathophysiological similarities, including immune dysregulation, increased thrombogenesis, and systemic inflammation. The relation between statins and risk of sepsis in patients with atherosclerosis is unknown.

METHODS

We did a population-based cohort analysis through linked administrative databases in Ontario, Canada, with accrual from 1997 to 2002. We identified 141,487 patients older than 65 years who had been hospitalised for an acute coronary syndrome, ischaemic stroke, or revascularisation, who survived for at least 3 months after discharge. 46,662 (33%) were prescribed a statin within 90 days of discharge, 94,825 (67%) were not. Propensity-based matching, which accounted for each individual's likelihood of receiving a statin, yielded a cohort of 69,168 patients, of whom half (34,584) received a statin and half (34,584) did not.

FINDINGS

Incidence of sepsis was lower in patients receiving statins than in controls (71.2 vs 88.0 events per 10,000 person-years; hazard ratio [HR] 0.81; 95% CI 0.72-0.91). Adjustment for demographic characteristics, sepsis risk factors, comorbidities, and health-care use gave similar results (HR 0.81; 95% CI 0.72-0.90). The protective association between statins and sepsis persisted in high-risk subgroups, including patients with diabetes mellitus, chronic renal failure, or a history of infections. Significant reductions in severe sepsis (HR 0.83; 95% CI 0.70-0.97) and fatal sepsis (0.75; 0.61-0.93) were also observed. No benefit was noted with non-statin lipid-lowering agents (0.95; 0.75-1.22).

IMPLICATIONS

Use of statins in patients with atherosclerosis is associated with a reduced risk of subsequent sepsis. Randomised trials of statins for prevention of sepsis are warranted.

Simvastatin protection against acute immune-mediated glomerulonephritis in mice

In addition to cholesterol lowering, 3-hydroxy-3-nethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors limit inflammatory changes associated with atherosclerosis. There is also support for their use as inhibitors of progression in chronic renal disease, irrespective of cause. In this study, their capacity to limit acute renal inflammation was evaluated. For this purpose, mice were treated with Simvastatin either prior to, at the time of, or shortly after induction of nephrotoxic nephritis. The severity of disease was determined by evaluation of blood urea nitrogen (BUN), proteinuria, and renal histologic changes. The reversibility of benefit was evaluated by the administration of mevalonic acid along with nephrotoxic serum (NTS) and Simvastatin The severity of the acute nephritis, including proteinuria, elevated BUN, and histologic changes, was ameliorated in a dose-dependent manner, when Simvastatin was administered either prior to NTS injection or at the time of NTS injection. By contrast, Simvastatin did not alter the course of established nephritis. Coadministration of mevalonic acid, the immediate substrate following HMG-CoA reductase, abolished Simvastatin's renoprotective effect, indicating that the benefit is, at least in part, due to interference with HMG-CoA reductase and biosynthetic substrates downstream from the enzyme. These findings provide the rationale for the evaluation of the efficacy of HMG-CoA reductase inhibitors in patients with recurrent forms of renal inflammation, to limit the severity of acute exacerbations of disease, prevent renal scarring and slow the rate of progression.

Effects of simvastatin in abdominal sepsis in rats

PURPOSE: Statins are widely recognized as hypolipemic drugs, but some studies have observed anti-inflammatory and immunomodulatory effects, known as pleiotropic. The aims of this work was to study possible anti-inflammatory effects of simvastatin in abdominal sepsis. Serum pro-inflammatory cytokines and leukocytes count were determined in an experimental model of abdominal sepsis, using cecal ligation and puncture (CLP) in rats. METHODS: Twenty eigth Wistar rats weighing 285±12g were randomly divided in: CLP/Sinvastatin rats (n=7), treated with 10 mg/Kg of oral simvastatin 18 and 2 hs berofe CLP; CLP/Saline group rats (n=7), treated with oral saline; group Sham/Simvastatin (n=7), treated with simvastatin, and group Sham/Saline (n=7), treated with saline. Serum TNF-alpha, IL-1beta and IL-6 by ELISA and total leukocytes, neutrophils, lymphocytes, and eosinophils were determined 24 hs after CLP. ANOVA and Tukey test were used considering significant p<0.05. RESULTS: It was demonstrated that serum TNF-alpha, IL-1beta and IL-6 were respectively 364,8±42pg/mL; 46,3±18pg/mL and 28,4±13pg/mL in CLP/Sinvastatin rats, significantly lower (p<0.05) than in group CLP/Saline (778,5±86pg/ml; 176,9±46pg/ml; 133,6±21 pg/ml, respectively). The same results were observed in total leukocytes and neutrophils counts. CONCLUSION: These results clearly demonstrate that simvastatin is an effective agent that reduces cytokines levels and leukocyte count in sepsis, independently of its well-known lipid-lowering effects. Thus, HMG-CoA reductase inhibitors like simvastatin have important anti-inflammatory effects in abdominal sepsis in rats.

Simvastatin induces caspase-independent apoptosis in LPS-activated RAW264.7 macrophage cells

Macrophages participate in several inflammatory pathologies such as sepsis and arthritis. We examined the effect of simvastatin on the LPS-induced proinflammatory macrophage RAW264.7 cells. Co-treatment of LPS and a non-toxic dose of simvastatin induced cell death in RAW264.7 cells. The cell death was accompanied by disruption of mitochondrial membrane potential (MMP), genomic DNA fragmentation, and caspase-3 activation. Surprisingly, despite caspase-dependent apoptotic cascade being completely blocked by Z-VAD-fmk, a pan-caspase inhibitor, the cell death was only partially repressed. In the presence of Z-VAD-fmk, DNA fragmentation was blocked, but DNA condensation, disruption of MMP, and nuclear translocation of apoptosis inducing factor were obvious. The cell death by simvastatin and LPS was effectively decreased by both the FPP and GGPP treatments as well as mevalonate. Our findings indicate that simvastatin triggers the cell death of LPS-treated RAW264.7 cells through both caspase-dependent and -independent apoptotic pathways, suggesting a novel mechanism of statins for the severe inflammatory disease therapy.

Dyslipidemia in the Critically Ill

Total and HDL cholesterol levels fall at the onset of acute illness and the cholesterol levels normalize as the patient recovers. Hypocholesterolemia may predispose the critically ill patient to sepsis and adrenal failure. Early enteral nutrition and tight glycemic control accelerate the recovery of the cholesterol levels.

Differential effects of statins on relevant functions of human monocyte-derived dendritic cells

Statins were shown to possess immunomodulating properties, but the mechanisms of statin effects on the immune system are poorly understood. We analyzed the influence of statins on professional antigen-presenting dendritic cells (DC). Immature DC were cultivated from monocytes of healthy donors. DC maturation was induced by lipopolysaccharide (LPS; 1 microg/mL). Unstimulated and LPS-stimulated DC were treated with simvastatin or atorvastatin (0.1-1 microM). The expression of CD40, CD83, CD86, and human leukocyte antigen-DR on unstimulated and LPS-stimulated DC was reduced significantly by statins, and the expression of Toll-like receptor 2 (TLR2) and TLR4 on LPS-stimulated DC was enhanced temporarily. Statins caused a significant reduction of endocytosis of fluorescein isothiocyanate-dextran by DC. Statins significantly inhibited the basal secretion of interleukin (IL)-6, IL-8, IL-12, and tumor necrosis factor alpha from unstimulated DC, and their release from LPS-stimulated DC was enhanced. In mixed leukocyte reaction, preincubation of LPS-stimulated DC with statins significantly suppressed their clustering with T cells and their ability to induce T cell proliferation, CD71, and CD25 up-regulation on T cells and the secretion of interferon-gamma and IL-2 from T cells. In conclusion, this study showed that statins suppressed endocytosis, basal secretion of proinflammatory cytokines, and the ability of DC to induce T cell proliferation, activation, and T helper cell type 1 differentiation. However, statin preincubation of LPS-stimulated DC caused a further increase in their secretion of proinflammatory cytokines.

Effect of simvastatin, an established lipid-lowering drug, on pulmonary Chlamydia pneumoniae infection in mice

The effects of simvastatin treatment on Chlamydia pneumoniae lung infection, inflammation, and serum lipids in mouse model were studied. Simvastatin decreased viable chlamydial counts and increased inflammatory cell infiltrates in the lung tissue, suggesting that simvastatin treatment had both antichlamydial and immunomodulatory effects during an acute C. pneumoniae infection.

Myocardial stiffness, cardiac remodeling, and diastolic dysfunction in calcification-prone fetuin-A-deficient mice

Accelerated atherosclerosis in dialysis patients is characterized by severe vascular calcification, and the magnitude of vascular calcification is associated with increased cardiovascular mortality. Calcification-dependent arterial stiffness is considered to be a major determinant of cardiac failure in uremia. Fetuin-A/alpha(2)-Heremans-Schmid glycoprotein is an abundant serum protein with powerful calcification inhibitory properties. Fetuin-A deficiency was recently linked to cardiovascular mortality in dialysis patients. Fetuin-A knockout (fetuin-KO) mice spontaneously develop widespread soft tissue calcification, including significant myocardial calcification, whereas larger arteries are spared. Therefore, this investigation offers the unique opportunity to study the functional role of isolated myocardial calcification independent of arterial stiffness by assessing the hemodynamics of fetuin-KO mice. Cardiac output in fetuin-KO mice was lower than in wild-type mice (fetuin-KO 1.81 +/- 0.18 versus WT 2.45 +/- 0.29 ml/min per g; P < 0.005), and fetuin-KO mice were refractory to dobutamine stimulation. Left ventricular relaxation was significantly impaired in fetuin-KO hearts with the relaxation index reduced by 23% (P < 0.005). After ischemia, fetuin-KO hearts displayed a continuous decline in left ventricular developed pressure after the initial phase of reperfusion, resulting in 77 +/- 15% of preischemic left ventricular developed pressure (P < 0.05 versus wild-type). In fetuin-KO mice, dystrophic cardiac calcification, with myocardial calcium contents increased 60-fold, was associated with profound induction of profibrotic TGF-beta and downstream collagen and fibronectin mRNA synthesis. In conclusion, independent of arterial stiffness, calcification-associated "myocardial stiffness" characterized by cardiac fibrosis, diastolic dysfunction, impaired tolerance to ischemia, and catecholamine resistance thus may constitute an underestimated cardiovascular risk factor that contributes to cardiac failure in calcification-prone states.

HMG-CoA reductase inhibition reduces monocyte CC chemokine receptor 2 expression and monocyte chemoattractant protein-1-mediated monocyte recruitment in vivo

BACKGROUND

The migration of circulating monocytes to the arterial wall during atherogenesis is largely modulated by activation of the CC chemokine receptor 2 (CCR2), a dominant monocyte chemotaxis receptor. The present study investigated whether 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibition affects CCR2 gene expression and CCR2-dependent monocyte recruitment.

METHODS AND RESULTS

Competitive reverse transcription-polymerase chain reaction analysis and flow cytometry showed that simvastatin, an HMG-CoA reductase inhibitor, dose-dependently reduced monocyte CCR2 mRNA and protein expression. Treatment of 21 normocholesterolemic men with simvastatin (20 mg/d for 2 weeks) decreased CCR2 protein and mRNA expression in circulating monocytes. Promoter and electrophoretic mobility shift assays showed that simvastatin activated a peroxisome proliferator response element in THP-1 monocytes. Moreover, simvastatin-induced CCR2 downregulation was completely reversed by the synthetic peroxisome proliferator-activated receptor-gamma antagonist GW9662. Simvastatin-treated monocytes showed little chemotaxis movement in response to monocyte chemoattractant protein-1 (MCP-1), a specific CCR2 ligand. Treatment of C57/BL6 mice with simvastatin (0.2 microg/g body weight IP, daily for 1 week) inhibited transmigration of CD80+ monocytes to the MCP-1-injected intraperitoneal space. Moreover, few circulating inflammatory cells from simvastatin-treated Sprague-Dawley rats (0.2 microg/g body weight IP, daily for 2 weeks) were recruited to the aortic wall of hypercholesterolemic littermates.

CONCLUSIONS

The inhibition of CCR2/MCP-1-dependent monocyte recruitment by simvastatin may prevent excessive accumulation of monocytes in the arterial wall during atherogenesis.

Animal models for radiation injury, protection and therapy

Current events throughout the world underscore the growing threat of different forms of terrorism, including radiological or nuclear attack. Pharmaceutical products and other approaches are needed to protect the civilian population from radiation and to treat those with radiation-induced injuries. In the event of an attack, radiation exposures will be heterogeneous in terms of both dose and quality, depending on the type of device used and each victim's location relative to the radiation source. Therefore, methods are needed to protect against and treat a wide range of early and slowly developing radiation-induced injuries. Equally important is the development of rapid and accurate biodosimetry methods for estimating radiation doses to individuals and guiding clinical treatment decisions. Acute effects of high-dose radiation include hematopoietic cell loss, immune suppression, mucosal damage (gastrointestinal and oral), and potential injury to other sites such as the lung, kidney and central nervous system (CNS). Long-term effects, as a result of both high- and low-dose radiation, include dysfunction or fibrosis in a wide range of organs and tissues and cancer. The availability of appropriate types of animal models, as well as adequate numbers of animals, is likely to be a major bottleneck in the development of new or improved radioprotectors, mitigators and therapeutic agents to prevent or treat radiation injuries and of biodosimetry methods to measure radiation doses to individuals.

Statin Treatment After Onset of Sepsis in a Murine Model Improves Survival

Background— HMG-CoA-reductase inhibitors have been shown to exhibit pronounced immunomodulatory effects independent of lipid lowering. We have recently demonstrated that pretreatment with simvastatin profoundly improves survival in a cecal ligation and perforation (CLP) model of sepsis. Here, we studied whether treatment with simvastatin after onset of sepsis-induced hemodynamic alterations is beneficial and whether prolonged survival can also be achieved with other statins.

Methods and Results— Mice were rendered septic by CLP. At 6 hours after sepsis induction, when profound hemodynamic alterations were manifest, treatment with atorvastatin, fluvastatin, pravastatin, simvastatin, or placebo was initiated. Except for fluvastatin (27±2.3 hours), survival time was extended from 23±1.2 hours for placebo-treated mice to 37±3.6 hours for simvastatin-treated, to 40±4.2 hours for atorvastatin-treated, and to 39±3.9 hours for pravastatin-treated mice. This profound improvement is based on the preservation of cardiac function and hemodynamic status in statin-treated animals, both of which are severely impaired in untreated CLP mice. As underlying mechanisms, improved susceptibility to endothelial nitric oxide synthase stimulation and reduced endothelial adhesion of leukocytes could be demonstrated after statin treatment.

Conclusions— Well established in the treatment of lipid disorders and coronary artery disease, statins harbor the additional and novel potential of effective sepsis treatment. This benefit extends to several but not all statins tested.

Statins Reduce Interleukin-6–Induced C-Reactive Protein in Human Hepatocytes

Objectives— Besides its predictive role in determining cardiovascular risk, C-reactive protein (CRP) may exert direct proatherogenic effects through proinflammatory properties. CRP is mainly produced by hepatocytes in response to interleukin-6 (IL-6) and is then released into the systemic circulation. 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitors, or statins, significantly reduce cardiovascular events and mortality in patients with or without coronary artery disease and reduce plasma CRP levels in humans. However, the mechanism by which statins reduce plasma CRP levels remains unknown.

Methods and Results— In this study, we report that statins limit both protein and RNA levels of IL-6-induced CRP in human hepatocytes. These effects are reversed by l -mevalonate and mimicked by an inhibitor of the geranylgeranyltransferase. IL-6–induced CRP production requires the binding of IL-6 to its cognate receptors, which results in activation and phosphorylation of the transcription factor STAT3. We provide evidence that statins reduce this IL-6–induced phosphorylation of STAT3 in hepatocytes.

Conclusion— These results demonstrate that statins reduce IL-6–induced CRP production directly in hepatocytes via inhibition of protein geranylgeranylation. We further show that statins act via inhibition of STAT3 phosphorylation. These findings furnish new evidence for direct antiinflammatory properties of statins and provide new mechanistic insight into their clinical benefits.

The statins--therapeutic diversity in renal disease?

PURPOSE OF REVIEW

Statins significantly reduce cholesterol synthesis and reduce cardiovascular morbidity and mortality. In addition, they appear to have beneficial effects independent of their ability to lower cholesterol. Recent publications suggesting a potential role for statin therapy in chronic renal insufficiency, hypertension and following organ transplantation are reviewed.

RECENT FINDINGS

Pharmacokinetic studies have shown statins to be well-tolerated and effective in patients on long-term haemodialysis, providing equivalent control of lipid levels to that seen in matched controls. Preliminary clinical trials suggest that statins may have beneficial disease-modifying effects in chronic inflammatory disease. Furthermore, immunosuppressive and immunomodulatory actions may confer benefit following cardiac transplantation, but this remains to be demonstrated definitively in renal transplant patients. Data to date suggest that, in addition to reduction of cardiovascular risk, statins may help slow the progress of chronic renal insufficiency, particularly in patients with proteinuria. Addition of statin therapy may also contribute to the control of systemic and pulmonary hypertension.

SUMMARY

Encouraging data in support of a wider spectrum of use for statins are emerging. In addition to reduction of cardiovascular risk through lipid lowering, they may represent an important adjunctive therapy in patients with chronic kidney diseases and post-transplantation. However, further large, well-designed clinical trials are required before their widespread use can be recommended in this setting.

Cardiovascular dysfunction caused by cecal ligation and puncture is attenuated in CD8 knockout mice treated with anti-asialoGM1

The present study was designed to assess hemodynamics and myocardial function at 18 h after injury caused by cecal ligation and puncture (CLP) in CD8-knockout mice treated with anti-asialoGM1 (CD8KO/alphaAsGM1 mice). Arterial pressure was measured by carotid artery cannulation, and left ventricular pressure-volume measurements were obtained by use of a 1.4-Fr conductance catheter. Blood acid-base balance and indexes of hepatic, renal, and pulmonary injury were also measured. CD8KO/alphaAsGM1 mice exhibited higher mean arterial pressure and increased systemic vascular resistance compared with wild-type mice. Cardiac output was significantly decreased in wild-type, but not CD8KO/alphaAsGM1, mice compared with sham controls. Myocardial function was better preserved in CD8KO/alphaAsGM1 mice as indicated by less impairment of left ventricular pressure development over time, time varying maximum elastance, end-systolic pressure-volume relationship, and preload recruitable stroke work. The impairment in myocardial function was associated with induction of proinflammatory cytokine mRNAs in the hearts of wild-type mice. The hemodynamic derangements in wild-type mice were coupled with significant metabolic acidosis and elevated serum creatinine levels. Overall, this study shows that cardiovascular collapse and shock characterized by hypotension, myocardial depression, low systemic vascular resistance, and metabolic acidosis occurs after CLP in wild-type mice but is attenuated in CD8KO/alphaAsGM1 mice. These observations likely explain, in part, the previously observed survival advantage of CD8KO/alphaAsGM1 mice following CLP.

Oxygen supply and nitric oxide scavenging by myoglobin contribute to exercise endurance and cardiac function

Recent studies of myoglobin (Mb) knockout (myo-/-) mice have extended our understanding of Mb's diverse functions and have demonstrated a complex array of compensatory mechanisms. The present study was aimed at detailed analysis of cardiac function and exercise endurance in myo-/- mice and at providing evidence for Mb's functional relevance. Myo-/- isolated working hearts display decreased contractility (dP/dtmax 3883+/-351 vs. 4618+/-268 mmHg/sec, myo-/- vs. WT, P<0.005). Due to a shift in sympathetic/parasympathetic tone, heart rate is reduced in conscious myo mice-/- (615+/-33 vs. 645+/-27 bpm, myo-/- vs. WT, P<0.001). Oxygen consumption (VO2) under resting conditions (3082+/-413 vs. 4452+/-552 ml x kg(-1) x h(-1), myo-/- vs. WT, P<0.001) and exercise endurance, as determined by spiroergometry, are decreased (466+/-113 vs. 585+/-153 m, myo-/- vs. WT, P<0.01). Conscious myo-/- mice evaluated by echocardiography display lowered cardiac output (0.64+/-0.06 vs. 0.75+/-0.09 ml x min(-1) x g(-1), myo-/- vs. WT, P<0.001), impaired systolic shortening (60+/-3.5 vs. 65+/-4%, myo-/- vs. WT, P<0.001) and fail to respond to beta1-stimulation. Strikingly, the latter cardiac effects of Mb deficiency can be partially attenuated by NOS inhibition. Loss of Mb results in a distinct phenotype, even under resting conditions, and the importance of oxygen supply and nitric oxide scavenging by Mb is clearly demonstrated at the conscious animal level.

Transplantation of human umbilical vein endothelial cells improves left ventricular function in a rat model of myocardial infarction

INTRODUCTION

Although cell-based therapy after myocardial infarction (MI) may be beneficial in improving cardiac dysfunction, the underlying mechanisms remain to be clarified. Since human umbilical vein endothelial cells (HUVEC) harbor the potential for transdifferentiation, we studied the functional effects of HUVEC transplantation in a rat model of MI.

METHODS AND RESULTS

HUVEC labeled with BrdU or medium alone were injected into the infarcted area and its margin 4 weeks after ligation of the left coronary artery in cyclosporine-treated rats. BrdU(+) signals could be detected in the area of MI at two weeks and two months after injection only in hearts transplanted with HUVEC. While no signs of transdifferentiation into cardiomyocytes were evident, staining for the rat macrophage marker ED-1, adjacent to or colocalized with BrdU(+) signals, revealed an in.ltration with macrophages and implied the phagocytosis of injected HUVEC. In the vicinity of BrdU(+) signals, the density of CD31(+) microvessels was significantly increased in HUVEC-transplanted as compared to medium-treated hearts after two months. HUVEC transplantation led to improved contractility as assessed by echocardiography and to higher coronary flow rates as well as to improved response to volume strain and catecholamine stress in Langendorff perfused hearts.

CONCLUSIONS

After MI, transplanted HUVEC persist in the host myocardium and trigger an infiltration with macrophages. The ensuing increase in neovascularization and improvement in global left ventricular function may be attributable to the associated inflammatory response.

Potential Role of Endotoxin as a Proinflammatory Mediator of Atherosclerosis

Atherosclerosis is increasingly recognized as a chronic inflammatory disease. Although a variety of inflammatory markers (ie, C-reactive protein) have been associated with atherosclerosis and its consequences, it is important to identify principal mediators of the inflammatory responses. One potentially important source of vascular inflammation in atherosclerosis is bacterial endotoxin. Mutations in Toll-like receptor 4 (TLR-4), an integral component of the endotoxin signaling complex, are fairly common in the Caucasian population and have recently been associated with reduced incidence of atherosclerosis and other cardiovascular diseases in some studies. Moreover, epidemiological studies suggest that endotoxemia at levels as low as 50 pg/mL constitutes a strong risk factor for the development of atherosclerosis. Endotoxin concentrations in this range may be produced by a variety of common subclinical Gram-negative infections. In this article, we outline the main elements of the endotoxin signaling receptor complex that initiates proinflammatory signaling (lipopolysaccharide binding protein [LBP], CD14, TLR-4, and MD-2) and discuss how changes in expression of these molecules may affect proatherogenic responses in the vessel wall. We also describe some of the proinflammatory effects of endotoxin that may be relevant to atherosclerosis, and discuss how serum lipoproteins, especially high-density lipoprotein, may modulate endotoxin-induced inflammatory responses. Further, we discuss recent findings suggesting that the lipid-lowering statins may have an additional protective role in blocking at least some of these proinflammatory signaling pathways. Finally, we discuss species diversity with regard to endotoxin signaling that should be considered when extrapolating experimental data from animal models to humans.

Simvastatin prevents vascular hyporeactivity during inflammation

BACKGROUND

There is growing evidence that statins exert anti-inflammatory and antioxidative vascular actions that are independent of lipid lowering. We tested whether hyporeactivity to the endothelium-dependent vasodilator acetylcholine (ACh) and the vasoconstrictor norepinephrine (NE) during acute experimental inflammation could be prevented by simvastatin.

METHODS AND RESULTS

In a randomized, placebo-controlled, parallel group study, forearm blood flow (FBF) responses to NE, ACh, and the endothelium-independent vasodilator nitroglycerin (NTG) were assessed at baseline, after 4 days of simvastatin 80 mg PO or placebo treatment, and during Escherichia coli endotoxin (lipopolysaccharide [LPS])-induced inflammation in 20 healthy volunteers. Additionally, markers of inflammation and neutrophil oxidative burst were assessed. Simvastatin and placebo had no effect on FBF or oxidative/inflammatory markers. LPS administration decreased the responses of FBF to NE by 43% (P<0.05) and decreased responses to ACh by 48% (P<0.05) but did not decrease FBF responses to NTG. Simvastatin completely preserved responses to NE and to ACh. The LPS-induced increases in neutrophil oxidative burst and plasma tumor necrosis factor-alpha concentrations were mitigated by simvastatin (P<0.05 versus placebo).

CONCLUSIONS

This study demonstrates potent vasoprotective properties of high-dose simvastatin during endotoxemia that may be useful for patients with acute systemic inflammation and associated vascular hyporeactivity.

Prior statin therapy is associated with a decreased rate of severe sepsis

BACKGROUND

Statins have anti-inflammatory properties that are independent of their lipid-lowering abilities. We hypothesized that statin therapy before the onset of an acute bacterial infection may have a protective effect against severe sepsis. The aim of this study was to determine whether patients treated with statins develop severe sepsis less frequently.

METHODS AND RESULTS

In this prospective observational cohort study, consecutive patients admitted with presumed or documented acute bacterial infection were enrolled. The primary outcomes were the rate of severe sepsis and intensive care unit (ICU) admission. Of the 361 patients enrolled, 82 (22.7%) were treated with statins before their admission. Both groups had a similar severity of illness on admission. Severe sepsis developed in 19% of patients in the no-statin group and in only 2.4% of the statin group (P<0.001). Statin treatment was associated with a relative risk of developing severe sepsis of 0.13 (95% CI, 0.03 to 0.52) and an absolute risk reduction of 16.6%. The overall ICU admission rate was 10.2% (37/361): 12.2% of the no-statin group required ICU admission, whereas in the statin group only 3.7% were admitted to the ICU (P=0.025), reflecting a relative risk of ICU admission of 0.30 (95% CI, 0.1 to 0.95).

CONCLUSIONS

Prior therapy with statins may be associated with a reduced rate of severe sepsis and ICU admission. If supported by prospective controlled trials, statins may have a role in the primary prevention of sepsis.