Potential benefits of statins on morbidity and mortality in chronic obstructive pulmonary disease: a review of the evidence

Chinese Herbs and Repurposing Old Drugs as Therapeutic Agents in the Regulation of Oxidative Stress and Inflammation in Pulmonary Diseases

Several pro-inflammatory factors and proteins have been characterized that are involved in the pathogenesis of inflammatory diseases, including acute respiratory distress syndrome, chronic obstructive pulmonary disease, and asthma, induced by oxidative stress, cytokines, bacterial toxins, and viruses. Reactive oxygen species (ROS) act as secondary messengers and are products of normal cellular metabolism. Under physiological conditions, ROS protect cells against oxidative stress through the maintenance of cellular redox homeostasis, which is important for proliferation, viability, cell activation, and organ function. However, overproduction of ROS is most frequently due to excessive stimulation of either the mitochondrial electron transport chain and xanthine oxidase or reduced nicotinamide adenine dinucleotide phosphate (NADPH) by pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor α. NADPH oxidase activation and ROS overproduction could further induce numerous inflammatory target proteins that are potentially mediated via Nox/ROS-related transcription factors triggered by various intracellular signaling pathways. Thus, oxidative stress is considered important in pulmonary inflammatory processes. Previous studies have demonstrated that redox signals can induce pulmonary inflammatory diseases. Thus, therapeutic strategies directly targeting oxidative stress may be effective for pulmonary inflammatory diseases. Therefore, drugs with anti-inflammatory and anti-oxidative properties may be beneficial to these diseases. Recent studies have suggested that traditional Chinese medicines, statins, and peroxisome proliferation-activated receptor agonists could modulate inflammation-related signaling processes and may be beneficial for pulmonary inflammatory diseases. In particular, several herbal medicines have attracted attention for the management of pulmonary inflammatory diseases. Therefore, we reviewed the pharmacological effects of these drugs to dissect how they induce host defense mechanisms against oxidative injury to combat pulmonary inflammation. Moreover, the cytotoxicity of oxidative stress and apoptotic cell death can be protected via the induction of HO-1 by these drugs. The main objective of this review is to focus on Chinese herbs and old drugs to develop anti-inflammatory drugs able to induce HO-1 expression for the management of pulmonary inflammatory diseases.

Mevalonate signaling, COPD and cancer: the statins and beyond

Evidence suggests that smoking confers a persistent and/or exaggerated inflammatory response in the lungs that, with underlying genetic susceptibility, may result in lung remodeling and impaired repair. The innate immune response to smoking described above, which is modified by the mevalonate pathway, provides a plausible pathogenic link between the development of chronic obstructive pulmonary disease and lung cancer. The mevalonate pathway modifies innate responsiveness through important intracellular signaling molecules called guanine phosphate transferases (GTPases) such as Rho-A. Smoke exposure activates cell surface proteins which, through the mediating influence of GTPases, then modifies the activation of nuclear factor kappa -light-chain-enhancer of activated B cells (NFĸB) its downstream effects on genes underlying innate immunity, neutrophilic inflammation and carcinogenesis. The mevalonate pathway is modifiable through the enzyme 3-hydroxy-3-methyl-glutaryl-Coenzyme A (HMGCo-A) reductase. This enzyme controls the rate limiting step of the mevalonate pathway and is subject to inhibition by statin drugs (HMGCo-A reductase inhibitors) and small chain fatty acids derived from high dietary fiber intake. Ths, inhibitory effect dampens the innate immune response to smoking and may modify pulmonary inflammation and lung remodeling. This article is a symposia summary outlining the preclinical and clinical data suggesting that statins and a high-fiber diet may have a chemopreventive effect on lung cancer.

Effectiveness of long-term using statins in COPD - a network meta-analysis

OBJECTIVES

To evaluate the effectiveness of long-term treatment of statins for chronic obstructive pulmonary disease (COPD), and to answer which one is better.

METHODS

General meta-analysis was performed to produce polled estimates of the effect of mortality, inflammatory factors, and lung function index in COPD patients by the search of PubMed, Web of Science, Embase, and China National Knowledge Infrastructure for eligible studies. A network meta-analysis was performed to synthetically compare the effectiveness of using different statins in COPD patients.

RESULTS

General meta-analysis showed that using statins reduced the risk of all-cause mortality, heart disease-related mortality and COPD acute exacerbation (AECOPD) in COPD patients, the RR (95% CI) were 0.72 (0.63,0.84), 0.72 (0.53,0.98) and 0.84 (0.79,0.89), respectively. And using statins reduced C-reactive protein (CRP) and pulmonary hypertension (PH) in COPD patients, the SMD (95% CI) were - 0.62 (- 0.52,-0.72) and - 0.71 (- 0.85,-0.57), respectively. Network meta-analysis showed that Fluvastatin (97.7%), Atorvastatin (68.0%) and Rosuvastatin (49.3%) had higher cumulative probability than other statins in reducing CRP in COPD patients. Fluvastatin (76.0%) and Atorvastatin (75.4%) had higher cumulative probability than other satins in reducing PH in COPD patients.

CONCLUSIONS

Using statins can reduce the risk of mortality, the level of CRP and PH in COPD patients. In addition, Fluvastatin and Atorvastatin are more effective in reducing CRP and PH in COPD patients.

Lung cancer and chronic obstructive pulmonary disease: From a clinical perspective

Chronic obstructive pulmonary disease (COPD) and lung cancer are devastating pulmonary diseases that commonly coexist and present a number of clinical challenges. COPD confers a higher risk for lung cancer development, but available chemopreventive measures remain rudimentary. Current studies have shown a marked benefit of cancer screening in the COPD population, although challenges remain, including the common underdiagnosis of COPD. COPD-associated lung cancer presents distinct clinical features. Treatment for lung cancer coexisting with COPD is challenging as COPD may increase postoperative morbidities and decrease survival. In this review, we outline current progress in the understanding of the clinical association between COPD and lung cancer, and suggest possible cancer prevention strategies in this patient population.

Statins reduce all-cause mortality in chronic obstructive pulmonary disease: an updated systematic review and meta-analysis of observational studies

Recently, a number of observational studies have suggested that use of statins reduces mortality in patients suffering from chronic obstructive pulmonary disease (COPD). To obtain a more valid assessment, we update the meta-analysis of the effect of statins on COPD exacerbation and mortality. We searched for eligible articles using PubMed, Medline, Embase, the Cochrane Central Register of Controlled Trials, Cochrane Databases and Web of Science between January 2006 and February 2017, with no restrictions. The hazard ratio (HR) with 95% confidence interval (CI) was estimated. Publication bias was evaluated by funnel plot and Begg's test. Sensitivity analyses were also conducted. Twenty studies with a total of 303,981 patients were included. Thirteen articles provided data on all-cause mortality (165,221 participants), and the pooled hazard ratio of 0.65 (95% CI: 0.57–0.74, P < 0.001). Nine cohorts involving 155,435 patients reported data for COPD exacerbation with or without hospitalization, and they gave a HR of 0.58(95%CI: 0.48–0.72, P < 0.001). Our systematic review of exclusively observational studies showed a clear benefit of statins for patients suffering from COPD.

Influence of Statin Therapy on Exacerbation Frequency in Patients with Chronic Obstructive Pulmonary Disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease, in which chronic and systemic inflammation plays an important role. By decreasing neutrophil infiltration and cytokine production, statins have anti-inflammatory mechanisms.

MATERIALS AND METHODS

Fifty-seven patients who had diagnosis of chronic obstructive pulmonary disease according to GOLD guideline were included in the study; 20 of them were statin users. Statin users group were patients being under medication with regular simvastatin, atorvastatin or rosuvastatin 20 mg per day for at least the past 1 year.

RESULTS

There was statistically no significant difference between patients with or without statin treatment with respect to; age, female-male ratio, COPD severity level, medication used for COPD, pulmonary function tests results and smoking habits. COPD exacerbation frequency in patients using statins was significantly less than patients not using statins (p<0.05). Patient number with COPD exacerbation, antibiotic treatment and outpatient clinic administration and outpatient clinic administration frequency was significantly lower in statin using patients (p<0.05).

CONCLUSION

COPD patients receiving statins have a lower frequency of COPD exacarbations, hospital administration and antibiotic treatment compared to patients not receiving statins.

Optimal treatment sequence in COPD: Can a consensus be found?

There is currently no consensus on the treatment sequence in chronic obstructive pulmonary disease (COPD), although it is recognized that early diagnosis is of paramount importance to start treatment in the early stages of the disease. Although it is fairly consensual that initial treatment should be with an inhaled short-acting beta agonist, a short-acting muscarinic antagonist, a long-acting beta-agonist or a long-acting muscarinic antagonist. As the disease progresses, several therapeutic options are available, and which to choose at each disease stage remains controversial. When and in which patients to use dual bronchodilation? When to use inhaled corticosteroids? And triple therapy? Are the existing non-inhaled therapies, such as mucolytic agents, antibiotics, phosphodiesterase-4 inhibitors, methylxanthines and immunostimulating agents, useful? If so, which patients would benefit? Should co-morbidities be taken into account when choosing COPD therapy for a patient? This paper reviews current guidelines and available evidence and proposes a therapeutic scheme for COPD patients. We also propose a treatment algorithm in the hope that it will help physicians to decide the best approach for their patients. The authors conclude that, at present, a full consensus on optimal treatment sequence in COPD cannot be found, mainly due to disease heterogeneity and lack of biomarkers to guide treatment. For the time being, and although some therapeutic approaches are consensual, treatment of COPD should be patient-oriented.

The effect of statins on chronic obstructive pulmonary disease exacerbation and mortality: a systematic review and meta-analysis of observational research

The objective of this study is to assess whether statin use is associated with beneficial effects on COPD outcomes. We conducted a systematic review and meta-analysis of all available studies describing the association between statin use and COPD mortality, exacerbations and cardiovascular events. Medline, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched, with no restrictions. The hazard ratio (HR) with 95% confidence interval (CI) was estimated. Fifteen studies with a total of 238,459 patients were included. Nine articles provided data on all-cause mortality (124,543 participants), and they gave a HR of 0.62 (95% CI 0.52 to 0.73). Three studies provided data on cancer mortality (90,077 participants), HR 0.83 (0.65 to 1.08); four studies on COPD mortality (88,767 participants), HR 0.48 (0.23 to 0.99); and three studies on cardiovascular mortality (90,041 participants), HR 0.93 (0.50 to 1.72). Six articles provided data on COPD exacerbation with or without hospitalization (129,796 participants), HR 0.64 (0.55 to 0.75). Additionally, the use of statins was associated with a significant reduction risk of myocardial infarction, but not for stroke. Our systematic review showed a clear benefit of statins in patients with COPD.

Coadministration of Atorvastatin and Amiodarone Increases the Risk of Pulmonary Fibrosis in Rats

OBJECTIVE

The purpose of this study was to evaluate the effect of atorvastatin administration on amiodarone-induced pulmonary fibrosis in rats.

MATERIALS AND METHODS

Thirty-six male Wistar rats were randomly divided into 4 groups. The control group (CTL) received distilled water (0.3 ml intratracheally on days 0 and 2 and 0.5 ml orally from day 0 for 3 weeks). The atorvastatin group (AT), in addition to intratracheal distilled water, received 1 mg/kg of atorvastatin orally from day 0 for 3 weeks. The amiodarone group (AMI) received 2 intratracheal instillations of amiodarone (6.25 mg/kg in 0.3 ml of water) on days 0 and 2 and 0.5 ml of distilled water (like the CTL). The amiodarone plus atorvastatin group (AMI + AT) received both these drugs (same doses and methods as for the AMI and AT). After 28 days, the rate of lung fibrosis was estimated according to pathological criteria of lung sections and measurements of hydroxyproline in pieces of left lung tissue.

RESULTS

The lung hydroxyproline content was higher in the treated groups (CTL: 0.35 ± 0.017, AT: 0.38 ± 0.012, AMI: 0.375 ± 0.018 and AMI + AT: 0.38 ± 0.012 unit/mg protein), but did not reach significance when compared with the CTL (p = 0.56). Amiodarone administration significantly increased the score of pulmonary fibrosis (0.5) in comparison with the AT (0.125) and CTL (0) (p < 0.5). The combination of amiodarone and atorvastatin exacerbated the pulmonary fibrosis (1.5; p < 0.01) compared to the AMI (0.5; p < 0.001), AT (0.125) and CTL (0).

CONCLUSION

In this study, the concomitant administration of amiodarone and atorvastatin increased pulmonary fibrosis in rats.

An Official American Thoracic Society/European Respiratory Society Statement: Research questions in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this Official American Thoracic Society (ATS)/European Respiratory Society (ERS) Research Statement is to describe evidence related to diagnosis, assessment, and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

METHODS

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarized, and then salient knowledge gaps were identified.

RESULTS

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulated via discussion and consensus.

CONCLUSIONS

Great strides have been made in the diagnosis, assessment, and management of COPD as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS Research Statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centered outcomes.

An official American Thoracic Society/European Respiratory Society statement: research questions in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this official American Thoracic Society (ATS)/European Respiratory Society (ERS) research statement is to describe evidence related to diagnosis, assessment and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarised, and then salient knowledge gaps were identified.

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulatedviadiscussion and consensus.

Great strides have been made in the diagnosis, assessment and management of COPD, as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS research statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centred outcomes.

Efficacy of HMG-CoA reductase inhibitors in the prevention of cerebrovascular attack in 1016 patients older than 75 years among 4014 type 2 diabetic individuals

BACKGROUND/OBJECTIVES

HMG-CoA reductase inhibitors (statins) reduce ischemic heart disease (IHD) in middle-aged diabetic individuals, and LDL-cholesterol (LDL-C) is a risk factor. However, their preventive effects on cerebrovascular attack (CVA) have not been identified in elderly, especially in elderly ≥ 75 years (late elderly), who account for approximately 30% of diabetic individuals in Japan. Randomized controlled studies of statins for late elderly are difficult to carry out, because many co-morbidities in elderly disrupt randomized controlled conditions.

METHODS

We performed a prospective cohort study (Japan Cholesterol and Diabetes Mellitus Study) with 5.5 years of follow-up since 2004. A total of 4014 type 2 diabetic patients without previous IHD or CVA (n=1936 women; age = 67.4 ± 9.5 years; ≥ 75 years: n = 1016) were enrolled, while 405 patients were registered as sub-cohort patients. We recorded detailed information on medications and laboratory data after every change in medication in patients of sub-cohort and suffered from IHD or CVA. We subdivided statin-users into prevalent, new and non-users.

RESULTS

A total of 104 CVAs occurred during 5.5-years. Plasma HDL-C level was inversely correlated with CVA in patients ≥ 65 years. In case-control study, among patients who were not prescribed statins, CVA increased in age-dependent manner. CVA incidence was lower in prevalent and new statin-users than in non-users (hazard ratio [HR]:0.46, 0.523), especially in late elderly (HR: 0.51, 0.21). Statins reduced CVAs mainly due to a direct effect and partially due to the effects of HDL-C and glucose metabolism. No significant differences were observed between statins.

CONCLUSION

Statins prevented CVA in middle-aged, elderly and late elderly diabetic patients via a direct effect. This study is the first to demonstrate the usefulness of observational studies for statistically analyzing agents' effects on late elderly.

In-hospital and one-year mortality and their predictors in patients hospitalized for first-ever chronic obstructive pulmonary disease exacerbations: a nationwide population-based study

Introduction

Natural history of chronic obstructive pulmonary disease (COPD) is punctuated by exacerbations; however, little is known about prognosis of the first-ever COPD exacerbation and variables predicting its outcomes.

Materials and Methods

A population-based cohort study among COPD patients with their first-ever exacerbations requiring hospitalizations was conducted. Main outcomes were in-hospital mortality and one-year mortality after discharge. Demographics, comorbidities, medications and in-hospital events were obtained to explore outcome predictors.

Results

The cohort comprised 4204 hospitalized COPD patients, of whom 175 (4%) died during the hospitalization. In-hospital mortality was related to higher age (odds ratio [OR]: 1.05 per year; 95% confidence interval [CI]: 1.03–1.06) and Charlson comorbidity index score (OR: 1.08 per point; 95% CI: 1.01–1.15); angiotensin II receptor blockers (OR: 0.61; 95% CI: 0.38–0.98) and β blockers (OR: 0.63; 95% CI: 0.41–0.95) conferred a survival benefit. At one year after discharge, 22% (871/4029) of hospital survivors were dead. On multivariate Cox regression analysis, age and Charlson comorbidity index remained independent predictors of one-year mortality. Longer hospital stay (hazard ratio [HR] 1.01 per day; 95% CI: 1.01–1.01) and ICU admission (HR: 1.33; 95% CI: 1.03–1.73) during the hospitalization were associated with higher mortality risks. Prescription of β blockers (HR: 0.79; 95% CI: 0.67–0.93) and statins (HR: 0.66; 95% CI: 0.47–0.91) on hospital discharge were protective against one-year mortality.

Conclusions

Even the first-ever severe COPD exacerbation signifies poor prognosis in COPD patients. Comorbidities play a crucial role in determining outcomes and should be carefully assessed. Angiotensin II receptor blockers, β blockers and statins may, in theory, have dual cardiopulmonary protective properties and probably alter prognosis of COPD patients. Nevertheless, the limitations inherent to a claims database study, such as the diagnostic accuracy of COPD and its exacerbation, should be born in mind.

Statin use and exacerbations in individuals with chronic obstructive pulmonary disease

BACKGROUND

We tested the hypothesis that statin use in individuals with COPD is associated with a reduced risk of exacerbations.

METHODS

We identified 5794 individuals with COPD and a measurement of C reactive protein (CRP) in the Copenhagen General Population Study (2003-2008). During 3 years of follow-up we recorded exacerbations with hospital admissions or oral corticosteroid treatment. In a nested case-control design, matching on age, gender, smoking, COPD severity and comorbidity, we estimated the association between statin use and exacerbations. In addition, we examined the association between statin use and high CRP (>3 mg/L), and the association between high CRP and exacerbations during follow-up.

RESULTS

Statin use was associated with reduced odds of exacerbations in crude analysis, OR=0.68 (95% CI 0.51 to 0.91, p=0.01), as well as in multivariable conditional logistic regression analysis, OR=0.67 (0.48 to 0.92, p=0.01). However, in the subgroup with the most severe COPD and without cardiovascular comorbidity, we observed a null association between statin use and exacerbations, OR=1.1 (0.5 to 2.1, p=0.83). Furthermore, statin use was associated with reduced odds of a high CRP, OR=0.69 (0.56 to 0.85, p<0.001), and a high CRP was associated with an increased risk of exacerbations, HR=1.62 (1.35 to 1.94, p<0.001). We estimated the percentage of excess risk of the association of statin use with exacerbations possibly mediated through a reduction of CRP to be 14% (4-51%).

CONCLUSIONS

Statin use was associated with reduced odds of exacerbations in individuals with COPD from the general population, although this was not apparent in those with the most severe COPD without cardiovascular comorbidity. Statins may thus only associate with reduced risk of exacerbations in patients with COPD with coexisting cardiovascular disease.

Statins reduce all-cause mortality in chronic obstructive pulmonary disease: a systematic review and meta-analysis of observational studies

BACKGROUND

Recent observational studies have suggested that use of statins reduces mortality in patients suffering from chronic obstructive pulmonary disease. However, no meta-analysis has reported the pooled hazard ratio of statins to all-cause mortality.

METHODS

We searched for eligible articles using five databases. We included randomized controlled trials and cohort studies written in English using original data reporting the hazard ratio of statins to all-cause, cardiovascular-related, cancer-related, or respiratory-related mortality. A fixed model with the confidence interval method was used. Publication bias was evaluated by funnel plot and Begg's test, and was corrected using Duval's trim and fill method. Sensitivity analyses were also conducted.

RESULTS

We included 10 out of 128 articles. The pooled hazard ratio of statins to all-cause mortality involving 16269 patients was 0.81 (95% CI: 0.75-0.86, P < 0.001) with moderate heterogeneity (I2 = 52%, P = 0.032). The sensitivity analysis and funnel plot suggested the existence of publication bias. After three possibly unpublished cohorts were imputed, the pooled hazard ratio of 0.83 (95% CI: 0.78-0.88, P < 0.001) still suggested a favorable prognosis in statin-treated patients. The pooled hazard ratio of statins to cardiovascular-related, cancer-related, and respiratory-related mortality were 0.52 (95% CI: 0.27-1.01, P = 0.052), 0.57 (95% CI: 0.32-1.01, P = 0.056), and 0.55 (95% CI: 0.43-0.78, P < 0.001), respectively, although these results were not conclusive as we could not find a sufficient number of original studies dealing with those forms of mortality.

CONCLUSIONS

The use of statins for patients suffering from chronic obstructive pulmonary disease may reduce all-cause mortality. This conclusion should be re-evaluated by a registered large-scale randomized controlled trial.

Predictors of early readmission among patients 40 to 64 years of age hospitalized for chronic obstructive pulmonary disease

RATIONALE

Various causes can contribute to the high rates of readmission among patients hospitalized with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the frequency and predictors of early readmission among patients aged 40-64 years, hospitalized with COPD.

METHODS

In a retrospective cohort study, using a large national commercial insurance database, we obtained the clinical information within 12 months of the index hospitalization and 30 days after discharge.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was early readmission, defined as hospitalization within 30 days of discharge. We categorized predictor variables as patient, provider, and system factors, and compared these variables between patients readmitted and those not readmitted. Logistic regression was used for multivariable analysis. Of 8,263 patients who met the inclusion criteria, 741 (8.9%) had early readmission. Multivariable analysis showed patient factors (male, history of heart failure, lung cancer, osteoporosis, and depression), provider factors (no prior prescription of statin within 12 mo of the index hospitalization and no prescription of short-acting bronchodilator, oral steroid and antibiotic on discharge), and system factors (length of stay, <2 or >5 d and lack of follow-up visit after discharge) were associated with early readmission among patients hospitalized with COPD. The C-statistic of the model including patient characteristics was 0.677 (95% confidence interval, 0.656-0.697), which was improved to 0.717 (95% confidence interval, 0.702-0.732) after addition of provider- and system-based factors.

CONCLUSIONS

One of 11 patients hospitalized with COPD is readmitted within 30 days of discharge. Provider and system factors are important modifiable risk factors of early readmission.

Targeting the mevalonate cascade as a new therapeutic approach in heart disease, cancer and pulmonary disease

The cholesterol biosynthesis pathway, also known as the mevalonate (MVA) pathway, is an essential cellular pathway that is involved in diverse cell functions. The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR) is the rate-limiting step in cholesterol biosynthesis and catalyzes the conversion of HMG-CoA to MVA. Given its role in cholesterol and isoprenoid biosynthesis, the regulation of HMGCR has been intensely investigated. Because all cells require a steady supply of MVA, both the sterol (i.e. cholesterol) and non-sterol (i.e. isoprenoid) products of MVA metabolism exert coordinated feedback regulation on HMGCR through different mechanisms. The proper functioning of HMGCR as the proximal enzyme in the MVA pathway is essential under both normal physiologic conditions and in many diseases given its role in cell cycle pathways and cell proliferation, cholesterol biosynthesis and metabolism, cell cytoskeletal dynamics and stability, cell membrane structure and fluidity, mitochondrial function, proliferation, and cell fate. The blockbuster statin drugs ('statins') directly bind to and inhibit HMGCR, and their use for the past thirty years has revolutionized the treatment of hypercholesterolemia and cardiovascular diseases, in particular coronary heart disease. Initially thought to exert their effects through cholesterol reduction, recent evidence indicates that statins also have pleiotropic immunomodulatory properties independent of cholesterol lowering. In this review we will focus on the therapeutic applications and mechanisms involved in the MVA cascade including Rho GTPase and Rho kinase (ROCK) signaling, statin inhibition of HMGCR, geranylgeranyltransferase (GGTase) inhibition, and farnesyltransferase (FTase) inhibition in cardiovascular disease, pulmonary diseases (e.g. asthma and chronic obstructive pulmonary disease (COPD)), and cancer.

Statin therapy does not improve lung function in asthma: a meta-analysis of randomized controlled trials

OBJECTIVE

To assess the efficacy of statins in the treatment of asthma.

METHODS

Electronic databases were searched to identify randomized controlled trials that measured the efficacy of statins in the treatment of asthma, and a meta-analysis of the pooled data was performed.

RESULTS

Five trials were identified; four met the inclusion criteria (total number of patients 200). Compared with controls, patients in the statin groups had higher forced expiratory volume in 1 s (FEV1) values before inhaled corticosteroids (0.09 l, 95% confidence interval [CI] -0.06, 0.23), higher FEV1 values after inhaled corticosteroids (0.06 l, 95% CI -0.09, 0.22), and higher morning peak expiratory flow rates (9.87 l, 95% CI -15.66, 35.40). These results were not statistically significant and, furthermore, publication bias was detected.

CONCLUSION

In conclusion, there is currently insufficient evidence to show that statins improve lung function in patients with asthma.

Relation between COPD severity and global cardiovascular risk in US adults

BACKGROUND

COPD is associated with the risk of cardiovascular events (CVEs), but its impact on overall mortality has not been well quantified. We determined the impact of global CVE risk assessment on CVE and total mortality in subjects with COPD.

METHODS

We examined the severity of COPD in 6,266 US adult patients aged 40 years in relation to the estimated 10-year risk of CVEs. COPD was defi ned by spirometry, and severity was classified as mild (FEV1 ≥ 80%), moderate (50% ≤ FEV< 1 , 80%), or severe (FEV 1 , 50%). Cox proportional hazards regression was used to evaluate the relationship of global CVE risk combined with COPD status to CVE and all-cause mortality over a mean follow-up of 98.8 ± 51.3 months.

RESULTS

The proportion of individuals at high risk for CVEs ranged from 25% (without COPD)to . 50% (with moderate to severe COPD) ( P , .05). When global CVE risk scores were low, CVE mortality was also low ( , 10/1,000 person-years) regardless of COPD severity, and CVE mortality was high when CVE global risk was high ( . 40/1,000 person-years). Global CVE risk improved prediction for both CVEs and total mortality in patients with COPD ( P , .0001), with a net reclassification improvement of 17.1% ( P , .0001) and 13.0% ( P , .0001), respectively, beyond lung function measures.

CONCLUSIONS

The addition of global CVE risk scores to lung function data significantly improves risk stratification of patients with COPD for CVE and total mortality and, thus, adds to predicting long-term survival of these patients.

Chronic obstructive pulmonary disease: an update of treatment related to frequently associated comorbidities

Chronic obstructive pulmonary disease (COPD) is associated with a pulmonary inflammatory response to inhaled substances, and individuals with COPD often have raised levels of several circulating inflammatory markers indicating the presence of systemic inflammation. Recently, there has been increasing interest in comorbidities associated with COPD such as skeletal muscle dysfunction, cardiovascular disease, osteoporosis, diabetes and lung cancer. These conditions are associated with a similar inflammation-based patho-physiology to COPD, and may represent a lung inflammatory 'overspill' to distant organs. Cardiovascular disease is a significant cause of mortality in COPD, and the concepts of an inflammatory link raise the possibility that treatment for one organ may show benefits to comorbidities in other organs. When considering treatment of COPD and its comorbidities, one approach is to target the pulmonary inflammation and hence reduce any 'overspill' effect of inflammatory mediators systemically as suggested by response to inhaled corticosteroids. Alternatively, treatment targeted towards comorbid organs may alter features of pulmonary disease as statins, angiotensin-converting enzyme (ACE) inhibitors and peroxisome proliferator-activated receptor (PPAR) agonists may have beneficial effects on COPD by reducing exacerbations and mortality. Newer anti-inflammatory treatments, such as phosphodiesterase 4 (PDE4), nuclear factor(NF)-kB, and p38 mitogen-activated protein kinase (MAPK) inhibitors, are given systemically and may confer benefits to both COPD and its comorbidities. With common inflammatory pathways it might be expected that successful anti-inflammatory therapy in one organ may also influence others. In this review we explore the concepts of systemic inflammation in COPD and current evidence for treatment of its related comorbidities.

Elevated cardiovascular risk among adults with obstructive and restrictive airway functioning in the United States: a cross-sectional study of the National Health and Nutrition Examination Survey from 2007-2010

BACKGROUND

Reasons for the excess risk for cardiovascular disease among people with chronic obstructive pulmonary disease remain unclear. Our objective was to examine the cardiovascular risk profile for adults with obstructive and restrictive impairments of lung functioning in a representative sample of adults from the United States.

METHODS

We used data from adults aged 20-79 years who participated in the National Health and Nutrition Examination Survey from 2007 to 2010 and had a pulmonary function test. The severity of obstructive impairment was defined by adapting the Global Initiative for Chronic Obstructive Lung Disease criteria.

RESULTS

Among 7249 participants, 80.9% had a normal pulmonary function test, 5.7% had a restrictive impairment, 7.9% had mild obstructive impairment, and 5.5% had moderate or severe/very severe obstructive impairment. Participants with obstructive impairment had high rates of smoking and increased serum concentrations of cotinine. Compared to participants with normal pulmonary functioning, participants with at least moderate obstructive impairment had elevated concentrations of C-reactive protein but lower concentrations of total cholesterol and non-high-density lipoprotein cholesterol. Among participants aged 50-74 years, participants with at least a moderate obstructive impairment or a restrictive impairment had an elevated predicted 10-year risk for cardiovascular disease.

CONCLUSIONS

The high rates of smoking among adults with impaired pulmonary functioning, particularly those with obstructive impairment, point to a need for aggressive efforts to promote smoking cessation in these adults. In addition, adults with restrictive impairment may require increased attention to and fine-tuning of their cardiovascular risk profile.

Mortality among subjects with chronic obstructive pulmonary disease or asthma at two respiratory disease clinics in Ontario

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and asthma are common; however, mortality rates among individuals with these diseases are not well studied in North America.

OBJECTIVE

To investigate mortality rates and risk factors for premature death among subjects with COPD.

METHODS

Subjects were identified from the lung function testing databases of two academic respiratory disease clinics in Hamilton and Toronto, Ontario. Mortality was ascertained by linkage to the Ontario mortality registry between 1992 and 2002, inclusive. Standardized mortality ratios were computed. Poisson regression of standardized mortality ratios and proportional hazards regression were performed to examine the multivariate effect of risk factors on the standardized mortality ratios and mortality hazards.

RESULTS

Compared with the Ontario population, all-cause mortality was approximately doubled among subjects with COPD, but was lower than expected among subjects with asthma. The risk of mortality in patients with COPD was related to cigarette smoking, to the presence of comorbid conditons of ischemic heart disease and diabetes, and to Global initiative for chronic Obstructive Lung Disease severity scores. Individuals living closer to traffic sources showed an elevated risk of death compared with those who lived further away from traffic sources.

CONCLUSIONS

Mortality rates among subjects diagnosed with COPD were substantially elevated. There were several deaths attributed to asthma among subjects in the present study; however, overall, patients with asthma demonstrated lower mortality rates than the general population. Subjects with COPD need to be managed with attention devoted to both their respiratory disorders and related comorbidities.

Statin use in COPD patients is associated with a reduction in mortality: a national cohort study

AIMS

To assess whether statin use is associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Hospitalisation, drug dispensing, and mortality records were linked for New Zealanders aged 50-80 years discharged from hospital with a first admission with COPD in 2006. Patients were classified according to whether or not they were prescribed statins prior to admission. Baseline characteristics were compared and hazard ratios calculated for statin users versus statin non-users for all-cause mortality over follow-up of up to 4 years.

RESULTS

A total of 1,687 patients (mean age 70.6 years) were followed, including 596 statin users and 1,091 non-users. There were more men in the statin user group (58.4% vs. 48.5%), and statin users were more likely to have a history of cardiovascular disease (58.6% vs. 25.1%), prescription for frusemide as a proxy for heart failure (47.7% vs. 24.5%) or diabetes (35.4% vs.11.6%) than statin non-users (p<0.001). A total of 671 deaths occurred during the follow-up period. After adjustment for age, sex, ethnic group, history of cardiovascular disease, diabetes, and prescription for frusemide, the hazard ratio for statin users vs. statin non-users for all-cause mortality was 0.69 (95% CI 0.58 to 0.84).

CONCLUSIONS

Statin use is associated with a 30% reduction in all-cause mortality at 3-4 years after first admission for COPD, irrespective of a past history of cardiovascular disease and diabetes.

Differential effects of simvastatin on IL-13-induced cytokine gene expression in primary mouse tracheal epithelial cells

Background

Asthma causes significant morbidity worldwide in adults and children alike, and incurs large healthcare costs. The statin drugs, which treat hyperlipidemia and cardiovascular diseases, have pleiotropic effects beyond lowering cholesterol, including immunomodulatory, anti-inflammatory, and anti-fibrotic properties which may benefit lung health. Using an allergic mouse model of asthma, we previously demonstrated a benefit of statins in reducing peribronchiolar eosinophilic inflammation, airway hyperreactivity, goblet cell hyperplasia, and lung IL-4 and IL-13 production.

Objectives

In this study, we evaluated whether simvastatin inhibits IL-13-induced pro-inflammatory gene expression of asthma-related cytokines in well-differentiated primary mouse tracheal epithelial (MTE) cell cultures. We hypothesized that simvastatin reduces the expression of IL-13-inducible genes in MTE cells.

Methods

We harvested tracheal epithelial cells from naïve BALB/c mice, grew them under air-liquid interface (ALI) cell culture conditions, then assessed IL-13-induced gene expression in MTE cells using a quantitative real-time PCR mouse gene array kit.

Results

We found that simvastatin had differential effects on IL-13-mediated gene expression (inhibited eotaxin-1; MCP-1,-2,-3; and osteopontin (SPP1), while it induced caspase-1 and CCL20 (MIP-3α)) in MTE cells. For other asthma-relevant genes such as TNF, IL-4, IL-10, CCL12 (MCP-5), CCL5 (RANTES), and CCR3, there were no significant IL-13-inducible or statin effects on gene expression.

Conclusions

Simvastatin modulates the gene expression of selected IL-13-inducible pro-inflammatory cytokines and chemokines in primary mouse tracheal epithelial cells. The airway epithelium may be a viable target tissue for the statin drugs. Further research is needed to assess the mechanisms of how statins modulate epithelial gene expression.

Comorbidities of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Defining the nature of the association between chronic obstructive pulmonary disease (COPD) and other chronic conditions is of primary importance to improve the health status of COPD patients through the optimal care of comorbidities. We aimed at providing a reasoned guide to understand, recognize and treat comorbidity of COPD with the perspective of shifting from comorbidity to multimorbidity.

RECENT FINDINGS

Select comorbidities, such as atherosclerotic disease, depression, chronic kidney disease, cognitive impairment, obstructive sleep apnea syndrome, lung cancer, osteoporosis, diabetes, heart failure, sarcopenia, aortic aneurysm, arrhythmias and pulmonary embolism are highly prevalent among older COPD patients. Several concerns may affect the management of older COPD patients with comorbidity (e.g. the use of β-blockers in patients with COPD and cardiovascular diseases or concerns about the cardiovascular safety of inhaled COPD drugs).

SUMMARY

Evidence suggests that systemic inflammation may be the link between COPD and comorbidities, but this issue is still debated. Whatever the mechanism underlying comorbidities in COPD may be, it has an important clinical, prognostic and therapeutic impact. Nevertheless, clinical practice guidelines do not take into account comorbidities in their recommendations. Additionally, clinical trials investigating COPD treatment in the context of multimorbidity and considering geriatric outcomes are also distinctly lacking.

How the genetics of lung cancer may overlap with COPD

Over the last 30years, epidemiological studies have shown that COPD is the single most important risk factor for lung cancer after smoking exposure. Recent genetic studies using genome-wide approaches suggest that the genetic risk factors predisposing smokers to COPD and lung cancer may overlap. The genes identified by these studies suggest that this overlapping genetic susceptibility may be mediated through receptors expressed on the bronchial epithelium that implicate molecular pathways underlying both COPD and lung cancer. Furthermore, it appears that aberrant inflammatory and/or immune-modulatory pathways leading to excess matrix metalloproteinases, growth factors and airway remodelling in COPD may also be promoting malignant transformation of the bronchial epithelium. The process linking inflammation, remodelling and cancer formation is called epithelial-mesenchymal transition. There are several clinical implications arising from the COPD-lung cancer overlap. First, if COPD is a precursor disease to lung cancer then efforts to prevent COPD, might be even more important. Second, if drugs targeting the overlapping molecular pathways can be identified, chemoprevention that reduce the propensity to COPD and lung cancer is an attractive option. Finally, if low-dose computerized tomography can identify treatable lung cancer, gene-based tests of susceptibility might help identify those smokers who should undergo radiological screening.

Statins and outcome after hospitalization for COPD exacerbation: a prospective study

BACKGROUND

Retrospective studies have shown that the use of statins is associated with reduced mortality and decreased hospitalizations from COPD, but data from prospective studies are lacking.

METHODS

We followed-up prospectively 245 patients admitted to hospital for exacerbations of COPD (ECOPD) with monthly evaluations for one year. The role of statins on outcomes was evaluated by Cox regression analysis after proper adjustments for age, gender, BMI, current smoking status, Charlson comorbidity index and COPD stage. Health-related quality of life (HRQoL) was evaluated by Saint George's Respiratory Questionnaire.

RESULTS

There was no effect of statins on either 30-day or 1-year mortality. Patients receiving statins presented a lower total number of ECOPD during the 1-year follow up (2.1 ± 2.7 vs. 2.8 ± 3.2 ECOPD/patient respectively, p = 0.037). After proper adjustments, the use of statins was associated with a lower risk for ECOPD [HR: 0.656 (95% CI: 0.454-0.946)] and severe ECOPD [HR: 0.608 (95%CI: 0.381-0.972)]. The group of statins presented better improvement in HRQoL at 2, 6 and 12 months (p < 0.001).

CONCLUSIONS

The use of statins in patients hospitalized for ECOPD was associated with a lower risk for subsequent ECOPD and severe ECOPD and improved HRQoL. These data support a possible beneficial role for these agents in COPD.

Chronic obstructive pulmonary disease: patho-physiology, current methods of treatment and the potential for simvastatin in disease management

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) is a severe disease that leads to a non-reversible obstruction of the small airways. The prevalence of this disease is rapidly increasing in developed countries, and in 2020 it has been predicted that this disease will reach the third cause of mortality worldwide. COPD patients do not respond well to current treatment modalities, such as bronchodilators and corticosteroids.

AREAS COVERED

This review article focuses on the patho-physiology of COPD, explores current approaches to alleviate and treat the disease, and discusses the potential use of statins for treatment. Specifically, the mechanism of action and metabolism of simvastatin, the most known and studied molecule among the statin family, are critically reviewed.

EXPERT OPINION

Various cellular pathways have been implicated in COPD, with alveolar macrophages emerging as pivotal inflammatory mediators in the COPD patho-physiology. Recently, emerging anti-cytokine therapies, such as PDE4 inhibitors and ACE inhibitors, have shown good anti-inflammatory properties that can be useful in COPD treatment. Recently, statins as a drug class have gained much interest with respect to COPD management, following studies which show simvastatin to exert effective anti-inflammatory effects, via inhibition of the mevalonic acid cascade in alveolar macrophages.

Screening for lung cancer: are we there yet?

PURPOSE OF REVIEW

In lung cancer screening with low-dose spiral computed tomography (LDCT), the proportion of stage I disease is 50-85%, and the survival rate for resected stage I disease can exceed 90%, but proof of real benefit in terms of lung cancer mortality reduction must come from the several randomized trials underway in Europe and in the USA. Our purpose is to update the readers on recent progress in medical knowledge in this field.

RECENT FINDINGS

Relevant novelties regarding technical and collateral aspects of lung cancer screening have been made available, covering the performance of detection systems and nodule evaluation protocols, means to increase cost-effectiveness, insight into the biology of lung cancer, promotion of minimally invasive and lung-sparing surgical options, effects of screening on smoking habits and early follow-up findings in one randomized trial of LDCT vs. clinical review.

CONCLUSION

Early follow-up data suggest that the effect of screening with LDCT on mortality might be smaller than expected, but definitive follow-up data are still awaited from all ongoing randomized trials. Lung cancer screening research is yielding a relevant body of medical knowledge that will be beneficial for other smoking-related diseases and contribute to a better understanding of lung cancer biology.