Review of published cases of adverse cardiovascular events after ingestion of energy drinks

Energy drink (ED) consumption has been linked to several adverse event reports, but there is limited data on related cardiovascular (CV) complications. We describe clinical characteristics, ED consumption profile, co-ingestions, and results of cardiovascular testing in a series of cardiovascular event reports temporally related to ED consumption from the literature. We searched PubMed and Embase for case reports in peer-reviewed journals from January 1, 1980, to February 1, 2013, in which an acute CV event was associated temporally with ED consumption. We identified 14 eligible articles involving 15 cases (5 atrial arrhythmias, 5 ventricular arrhythmias, 1 QT prolongation, 4 ST-segment elevations). Two additional cases of cardiac arrest from our institution are included. Of these 17 cases of ED-related acute CV events (13 male cases; 15 cases aged <30 years, age range 13 to 58 years), only 1 had minor previous cardiac disease. Cardiac investigations did not reveal any predisposing cardiac abnormality in the majority of cases. Of the 11 cases related to a serious event (i.e., cardiac arrest, ventricular arrhythmia, or ST-segment elevations), 5 reported acute heavy ED consumption, 4 reported co-ingestions with alcohol or other drugs, and 2 were found to have a channelopathy. Potential mechanisms of ED-related cardiac events are reviewed. In conclusion, several adverse CV events after consuming ED have been reported in the literature. Although causality cannot be inferred from our series, physicians should routinely inquire about ED consumption in relevant cases, and vulnerable consumers such as youth should be advised that caution is warranted with heavy consumption and/or with concomitant alcohol or drug ingestion.

Do statins lower testosterone and does it matter?

Drugs are two-sided swords and statins are no exception. Schooling et al. demonstrate that, on average, statins produce small, but statistically significant, decreases in testosterone. They appropriately emphasize that the clinical significance of their observations is unclear but suggest that changes in testosterone might be related to the benefits of therapy as well as the risks, such as the increased chance of diabetes mellitus. Their findings and hypotheses are noteworthy. However, we believe this represents another example of the limitations in the published summaries of drug effects. How do we know all changes induced by drugs are normally distributed? Some may be affected much more than others. Moreover, the confidence intervals of a meta-analysis describe the variance of the mean effect, not the range of effects, and while the mean change characterizes the impact of a drug on a group of patients, the range more fully characterizes its effects on individuals. We treat individuals not groups. Averages do not disclose enough about the risks and benefits of drugs. See related research article here http://www.biomedcentral.com/1741-7015/11/57.

Genetic associations with valvular calcification and aortic stenosis

BACKGROUND

Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease.

METHODS

We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis.

RESULTS

One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10(-10)), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P=1.5×10(-8) and P=1.8×10(-8), respectively), but the findings were not replicated consistently.

CONCLUSIONS

Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aortic-valve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.).

Resequencing and clinical associations of the 9p21.3 region: a comprehensive investigation in the Framingham heart study

BACKGROUND

9p21.3 is among the most strongly replicated regions for cardiovascular disease. There are few reports of sequencing the associated 9p21.3 interval. We set out to sequence the 9p21.3 region followed by a comprehensive study of genetic associations with clinical and subclinical cardiovascular disease and its risk factors, as well as with copy number variation and gene expression, in the Framingham Heart Study (FHS).

METHODS AND RESULTS

We sequenced 281 individuals (94 with myocardial infarction, 94 with high coronary artery calcium levels, and 93 control subjects free of elevated coronary artery calcium or myocardial infarction), followed by genotyping and association in >7000 additional FHS individuals. We assessed genetic associations with clinical and subclinical cardiovascular disease, risk factor phenotypes, and gene expression levels of the protein-coding genes CDKN2A and CDKN2B and the noncoding gene ANRIL in freshly harvested leukocytes and platelets. Within this large sample, we found strong associations of 9p21.3 variants with increased risk for myocardial infarction, higher coronary artery calcium levels, and larger abdominal aorta diameters and no evidence for association with traditional cardiovascular disease risk factors. No common protein-coding variation, variants in splice donor or acceptor sites, or copy number variation events were observed. By contrast, strong associations were observed between genetic variants and gene expression, particularly for a short isoform of ANRIL and for CDKN2B.

CONCLUSIONS

Our thorough genomic characterization of 9p21.3 suggests common variants likely account for observed disease associations and provides further support for the hypothesis that complex regulatory variation affecting ANRIL and CDKN2B gene expression may contribute to increased risk for clinically apparent and subclinical coronary artery disease and aortic disease.

Periaortic adipose tissue and aortic dimensions in the Framingham Heart Study

Background

Periaortic fat, because of its contiguity with the aorta, may promote vascular remodeling and aortic dilatation. However, the relations between perioartic fat depots and aortic dimensions have not been previously described.

Methods and Results

A total of 3001 individuals (mean age 50±10 years, 49% women) from the Framingham Offspring and Third Generation cohorts underwent computed tomography for quantification of periaortic fat and aortic dimensions. We estimated the association between quantitative periaortic and visceral adipose tissue volumes (per standard deviation [SD] increment of volume) with aortic dimensions in both the thorax and abdomen. Thoracic periaortic fat was associated with higher thoracic aortic dimensions (β coefficient per SD of fat volume 0.67 mm, 95% confidence interval 0.58 to 0.76 mm; P<0.001). The association persisted after adjustment for age, sex, and cardiovascular risk factors including body mass index and visceral adipose tissue volume. Results for the association of periaortic fat and abdominal aortic dimensions were similar. Further adjustment for adipokines (resistin and adiponectin) had no significant impact on these associations.

Conclusions

Periaortic fat volume was associated with aortic dimensions in both the thorax and abdomen, supporting the notion that local fat depots may contribute to aortic remodeling. Further work to understand the mechanisms underlying this association is warranted.

Mendelian randomization: how genetics is pushing the boundaries of epidemiology to identify new causes of heart disease

The past 10 years have seen a remarkable revolution in the genetics of cardiovascular (CV) disease. Although much work remains to bring these discoveries to the bedside, genetics has opened up remarkable possibilities in understanding the causes of CV disease through a relatively novel study design known as "Mendelian randomization." Akin to a randomized trial, Mendelian randomization is a genetic study design that takes advantage of the "randomization" of genetic information at birth to evaluate a potential causal relationship between a genetically determined biomarker and an outcome. By providing evidence for causal relationships, Mendelian randomization can improve our understanding of fundamental mechanisms in human disease, potentially accelerate the identification of bona fide drug targets, and ultimately improve the care of patients with CV disease. This review describes the concept and design of Mendelian randomization genetic studies, discusses their strengths and weaknesses, and presents recent examples of Mendelian randomization studies in the CV literature that have helped clarify the causal role of selected biomarkers in CV medicine.

Comparison of coronary calcium screening versus broad statin therapy for patients at intermediate cardiovascular risk

Net reclassification has become widely accepted as a method to demonstrate whether new diagnostic technologies add significantly to the discrimination of risk. However, more accurate categorization of risk does not necessarily result in a better clinical outcome. This study examined whether coronary artery calcium, a technology that improves net reclassification in patients at intermediate risk for cardiovascular events, is superior to a strategy that calls for broader intervention with statin therapy in these patients. To do so, the clinical impact and costs of 2 intervention regimens on outcome in the Multi-Ethnic Study of Atherosclerosis (MESA) were calculated based on the known efficacy of statins. Intervention 1 involved treatment of all subjects at conventional intermediate risk with moderate-dose stain, whereas intervention 2 involved moderate- and high-dose statin therapy, respectively, of those remaining at intermediate risk and those reassigned to high risk after reclassification by coronary artery calcium. The 2 strategies would decrease clinical events by 23% and would produce net savings. However, these would be greater with the broad statin prevention strategy than with the coronary calcium reclassification strategy ($732,152 vs $288,336, respectively). In conclusion, even in the short term, the broad statin prevention strategy would be at least as effective in decreasing clinical events but with greater net savings than a prevention strategy using coronary calcium screening.

Relations of exercise blood pressure response to cardiovascular risk factors and vascular function in the Framingham Heart Study

BACKGROUND

Exercise blood pressure (BP) is an important marker of left ventricular hypertrophy, incident hypertension, and future cardiovascular events. Although impaired vascular function is hypothesized to influence the BP response during exercise, limited data exist on the association of vascular function with exercise BP in the community.

METHODS AND RESULTS

Framingham Offspring cohort participants (n=2115, 53% women, mean age 59 years) underwent a submaximal exercise test (first 2 stages of the Bruce protocol), applanation tonometry, and brachial artery flow-mediated dilation testing. We related exercise systolic and diastolic BP at second stage of the Bruce protocol to standard cardiovascular risk factors and to vascular function measures. In multivariable linear regression models, exercise systolic BP was positively related to age, standing BP, standing heart rate, smoking, body mass index, and the total cholesterol-to-high-density cholesterol ratio (P≤0.01 for all). Similar associations were observed for exercise diastolic BP. Carotid-femoral pulse wave velocity (P=0.02), central pulse pressure (P<0.0001), mean arterial pressure (P=0.04), and baseline brachial flow (P=0.002) were positively associated with exercise systolic BP, whereas flow-mediated dilation was negatively associated (P<0.001). For exercise diastolic BP, forward pressure wave amplitude was negatively related (P<0.0001), whereas mean arterial pressure was positively related (P<0.0001).

CONCLUSIONS

Increased arterial stiffness and impaired endothelial function are significant correlates of a higher exercise systolic BP response. Our findings suggest that impaired vascular function may contribute to exaggerated BP responses during daily living, resulting in repetitive increments in load on the heart and vessels and increased cardiovascular disease risk.

The causal exposure model of vascular disease

Primary prevention of cardiovascular disease is governed at present by the risk factor model for cardiovascular events, a model which is widely accepted by physicians and professional associations, but which has important limitations: most critically, that effective treatment to reduce arterial damage is often delayed until the age at which cardiovascular events become common. This delay means that many of the early victims of vascular disease will not be identified in time. This delay also allows atherosclerosis to develop and progress unchecked within the arterial tree with the result that the absolute effectiveness of preventive therapy is limited by the time it is eventually initiated. The causal exposure model of vascular disease is an alternative to the risk factor model for cardiovascular events. Whereas the risk factor model aims to identify and treat those at markedly increased risk of vascular events within the next decade, the causal exposure model of vascular disease aims to prevent events by treating the causes of the disease when they are identified. In the risk factor model, age is an independent non-modifiable risk factor and the predictive power of age far outweighs that of the other risk factors. In the causal exposure model, age is the duration of time the arterial wall is exposed to the causes of atherosclerosis: apoB (apolipoprotein B) lipoproteins, hypertension, diabetes and smoking. Preventing the development of advanced atherosclerotic lesions by treating the causes of vascular disease is the simplest, surest and most effective way to prevent clinical events.

A genetic risk score is associated with incident cardiovascular disease and coronary artery calcium: the Framingham Heart Study

BACKGROUND

Limited data exist regarding the use of a genetic risk score (GRS) for predicting risk of incident cardiovascular disease (CVD) in US-based samples.

METHODS AND RESULTS

By using findings from recent genome-wide association studies, we constructed GRSs composed of 13 genetic variants associated with myocardial infarction or other manifestations of coronary heart disease (CHD) and 102 genetic variants associated with CHD or its major risk factors. We also updated the 13 single-nucleotide polymorphism (SNP) GRSs with 16 SNPs recently discovered by genome-wide association studies. We estimated the association, discrimination, and risk reclassification of each GRS for incident cardiovascular events and prevalent coronary artery calcium (CAC). In analyses adjusted for age, sex, CVD risk factors, and parental history of CVD, the 13 SNP GRSs were significantly associated with incident hard CHD (hazard ratio, 1.07; 95% CI, 1.00-1.15; P=0.04), CVD (hazard ratio per allele, 1.05; 95% CI, 1.01-1.09; P=0.03), and high CAC (defined as >75(th) age- and sex-specific percentile; odds ratio per allele, 1.18; 95% CI, 1.11-1.26; P=3.4×10(-7)). The GRS did not improve discrimination for incident CHD or CVD but led to modest improvements in risk reclassification. However, significant improvements in discrimination and risk reclassification were observed for the prediction of high CAC. The addition of 16 newly discovered SNPs to the 13 SNP GRSs did not significantly modify these results.

CONCLUSIONS

A GRS composed of 13 SNPs associated with coronary disease is an independent predictor of cardiovascular events and of high CAC, modestly improves risk reclassification for incident CHD, and significantly improves discrimination for high CAC. The addition of recently discovered SNPs did not significantly improve the performance of this GRS.

Gout, allopurinol use, and heart failure outcomes

BACKGROUND

Hyperuricemia is associated with reduced survival among patients with heart failure (HF), but the effect of gout on HF outcomes is unknown. A recent randomized trial suggested that allopurinol may reduce adverse outcomes among patients with hyperuricemia and HF. Our objective was to determine whether gout and allopurinol use are associated with HF outcomes.

METHODS

Time-matched, nested case-control analysis of a retrospective cohort of patients with HF who were 66 years or older using health care databases in Quebec, Canada. The primary outcome measure was a composite measure of HF readmission and all-cause mortality. The secondary outcome measure was all-cause mortality. Rate ratios were calculated using conditional logistic regression and adjusted for known prognostic factors.

RESULTS

Of the 25,090 patients in this cohort, 14,327 experienced the primary outcome. Both a remote history of gout and an acute episode of gout (within 60 days of the event date) were associated with an increased risk of HF readmission or death (adjusted rate ratio, 1.63; 95% confidence interval, 1.48-1.80; P<.001 and 2.06; 1.39-3.06; P<.001, respectively). Continuous allopurinol use (>30 days of continuous use) was not associated with the primary outcome among the overall population with HF (adjusted rate ratio, 1.02; 95% confidence interval, 0.95-1.10; P=.55) but was associated with reduced HF readmissions or death (0.69; 0.60-0.79; P<.001) and all-cause mortality (0.74; 0.61-0.90; P<.001) among patients with a history of gout.

CONCLUSIONS

Patients with HF and a history of gout represent a high-risk population. Among such patients, the use of allopurinol is associated with improved outcomes.

Pericardial fat is associated with prevalent atrial fibrillation: the Framingham Heart Study

BACKGROUND

Obesity represents an important risk factor for atrial fibrillation (AF). We tested the hypothesis that pericardial fat, a unique fat deposit in close anatomic proximity to cardiac structures and autonomic fibers, is associated with prevalent AF.

METHODS AND RESULTS

Participants from the Framingham Heart Study underwent multidetector computed tomography from 2002 to 2005. We estimated the association between quantitative pericardial, intrathoracic and visceral adipose tissue volumes (per standard deviation of volume) with prevalent AF adjusting for established AF risk factors (age, sex, systolic blood pressure, blood pressure treatment, PR interval, and clinically significant valvular disease). Of the 3217 eligible participants (mean age, 50.6+/-10.1 years; 48% women), 54 had a confirmed diagnosis of AF. Pericardial fat but not intrathoracic or visceral abdominal fat was associated with prevalent AF in multivariable-adjusted models (odds ratio per standard deviation of pericardial fat volume, 1.28; 95% confidence intervals, 1.03 to 1.58). Further adjustments for body mass index, heart failure, myocardial infarction, and intrathoracic fat volume did not materially change the association between pericardial fat and AF.

CONCLUSIONS

Pericardial fat was associated with prevalent AF even after adjustment for AF risk factors, including body mass index. If this association is replicated, further investigations into the mechanisms linking pericardial fat to AF are merited.

Associations of long-term and early adult atherosclerosis risk factors with aortic and mitral valve calcium

OBJECTIVES

To determine the association of long-term exposure to atherosclerosis risk factors with valvular calcification.

BACKGROUND

Traditional atherosclerosis risk factors have been associated with aortic and mitral valve calcium in cross-sectional studies, but long-term prospective data are lacking.

METHODS

This was a prospective, community-based cohort study with 27-year follow-up (median follow-up 26.9 years; range 23.1 to 29.6 years). Participants from the Framingham Offspring Study (n = 1,323, enrolled between 1971 and 1975, mean age at enrollment 34 +/- 9 years; 52% women) underwent cardiac multidetector computed tomography assessment between 2002 and 2005. Associations between the long-term average of each cardiovascular risk factor and valve calcium were estimated using logistic regression.

RESULTS

Aortic valve calcium was present in 39% of participants and mitral valve calcium in 20%. In multivariable models, the odds ratio for aortic valve calcium associated with every SD increment in long-term mean total cholesterol was 1.74 (p < 0.0001); with every SD increment in high-density lipoprotein cholesterol, it was 0.77 (p = 0.002); and with every 9 cigarettes smoked per day, it was 1.23 (p = 0.002). Associations of similar magnitude were seen for mitral valve calcium. The mean of 3 serum C-reactive protein measurements was associated with mitral valve calcium (odds ratio: 1.29 per SD increment in C-reactive protein levels; p = 0.002). A higher Framingham risk score in early adulthood (40 years age or younger) was associated with increased prevalence and severity of aortic valve calcium measured 3 decades later.

CONCLUSIONS

Exposure to multiple atherosclerotic risk factors starting in early to mid-adulthood is associated with aortic and mitral valve calcium. Studies evaluating early risk factor modification to reduce the burden of valve disease are warranted.

Prevalence, distribution, and risk factor correlates of high pericardial and intrathoracic fat depots in the Framingham heart study

BACKGROUND

Pericardial and intrathoracic fat depots may represent novel risk factors for obesity-related cardiovascular disease. We sought to determine the prevalence, distribution, and risk factor correlates of high pericardial and intrathoracic fat deposits.

METHODS AND RESULTS

Participants from the Framingham Heart Study (n=3312; mean age, 52 years; 48% women) underwent multidetector CT imaging in 2002 to 2005; high pericardial and high intrathoracic fat were defined on the basis of the sex-specific 90th percentile for these fat depots in a healthy reference sample. For men and women, the prevalence of high pericardial fat was 29.3% and 26.3%, respectively, and high intrathoracic fat was 31.4% and 35.3%, respectively. Overall, 22.1% of the sample was discordant for pericardial and intrathoracic fat depots: 8.3% had high pericardial but normal intrathoracic fat and 13.8% had high intrathoracic but normal pericardial fat. Higher body mass index, higher waist circumference, and increased prevalence of metabolic syndrome were more prevalent in participants with high intrathoracic fat depots than with high pericardial fat (P<0.05 for all comparisons). High abdominal visceral adipose tissue was more frequent in participants with high intrathoracic adipose tissue compared with those with high pericardial fat (P<0.001). Intrathoracic fat but not waist circumference was more highly correlated with visceral adipose tissue (r=0.76 and 0.78 in men and women, respectively; P<0.0001) than with subcutaneous adipose tissue (SAT) (r=0.46 and 0.54 in men and women, respectively; P<0.0001).

CONCLUSIONS

Although prevalence of pericardial fat and intrathoracic fat were comparable at 30%, intrathoracic fat correlated more closely with metabolic risk and visceral fat. Intrathoracic fat may be a potential marker of metabolic risk and visceral fat on thoracic imaging.

Impact of restrictive prescription plans on heart failure medication use

BACKGROUND

Prescription plans frequently use restrictive strategies to control drug expenditures. Increased restrictions may reduce access to evidence-based therapy among patients with chronic disease. We sought to evaluate the impact of increased restrictions on medication use among heart failure (HF) patients.

METHODS AND RESULTS

We conducted a population-based cohort study of administrative data from 3 Canadian provinces. During 1998 to 2001, Quebec (QC) had a minimally restrictive plan, whereas Ontario (ON) and British Columbia (BC) had more restrictive prescription plans. We evaluated drug use at 30 days of discharge stratified by prescription plan. Provincial rates of filled prescriptions for HF drugs in QC, ON, and BC were 62%, 58%, and 47% for angiotensin-converting enzyme inhibitors; 34%, 22%, and 16% for beta-blockers; 9%, 5%, and 3% for angiotensin receptor blockers; and 79%, 76%, and 62% for loop diuretics, respectively. In multivariate analyses, patients residing in provinces with restrictive plans were less likely to be prescribed drugs that were restricted, such as beta-blockers (odds ratio, 0.53; 95% CI, 0.46 to 0.60; 0.36, 0.29 to 0.44, for ON and BC, respectively) and angiotensin receptor blockers (0.50, 0.45 to 0.56; 0.38, 0.32 to 0.46, for ON and BC, respectively), than drugs with no restrictions, such as loop diuretics (0.81, 0.74 to 0.88; 0.40, 0.36 to 0.45, for ON and BC, respectively) and angiotensin-converting enzyme inhibitors (0.80, 0.75 to 0.86; 0.47, 0.43 to 0.52, for ON and BC, respectively).

CONCLUSIONS

Among HF patients, residing in a province with a more restrictive prescription plan may be associated with lower use of restricted HF medications over and above the expected regional differences in HF drug use across provinces.

Outcomes in adults with bicuspid aortic valves

CONTEXT

Bicuspid aortic valve is the most common congenital cardiac anomaly in the adult population. Cardiac outcomes in a contemporary population of adults with bicuspid aortic valve have not been systematically determined.

OBJECTIVE

To determine the frequency and predictors of cardiac outcomes in a large consecutive series of adults with bicuspid aortic valve.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study examining cardiac outcomes in 642 consecutive ambulatory adults (mean [SD] age, 35 [16] years; 68% male) with bicuspid aortic valve presenting to a Canadian congenital cardiac center from 1994 through 2001 and followed up for a mean (SD) period of 9 (5) years. Frequency and predictors of major cardiac events were determined by multivariate analysis. Mortality rate in the study group was compared with age- and sex-matched population estimates.

MAIN OUTCOME MEASURES

Mortality and cause of death were determined. Primary cardiac events were defined as the occurrence of any of the following complications: cardiac death, intervention on the aortic valve or ascending aorta, aortic dissection or aneurysm, or congestive heart failure requiring hospital admission during the follow-up period.

RESULTS

During the follow-up period, there were 28 deaths (mean [SD], 4% [1%]). One or more primary cardiac events occurred in 161 patients (mean [SD], 25% [2%]), which included cardiac death in 17 patients (mean [SD], 3% [1%]), intervention on aortic valve or ascending aorta in 142 patients (mean [SD], 22% [2%]), aortic dissection or aneurysm in 11 patients (mean [SD], 2% [1%]), or congestive heart failure requiring hospital admission in 16 patients (mean [SD], 2% [1%]). Independent predictors of primary cardiac events were age older than 30 years (hazard ratio [HR], 3.01; 95% confidence interval [CI], 2.15-4.19; P<.001), moderate or severe aortic stenosis (HR, 5.67; 95% CI, 4.16-7.80; P<.001), and moderate or severe aortic regurgitation (HR, 2.68; 95% CI, 1.93-3.76; P<.001). The 10-year survival rate of the study group (mean [SD], 96% [1%]) was not significantly different from population estimates (mean [SD], 97% [1%]; P = .71). At last follow-up, 280 patients (mean [SD], 45% [2%]) had dilated aortic sinus and/or ascending aorta.

CONCLUSIONS

In this study population of young adults with bicuspid aortic valve, age, severity of aortic stenosis, and severity of aortic regurgitation were independently associated with primary cardiac events. Over the mean follow-up duration of 9 years, survival rates were not lower than for the general population.

Genetic lipoprotein disorders and coronary atherosclerosis

Familial lipoprotein disorders are seen frequently in subjects with premature coronary artery disease. The genetic basis for several dyslipoproteinemias has been elucidated in the past two decades. The majority of lipoprotein disorders result from a combination of polygenic predisposition and poor lifestyle habits, including physical inactivity, increased visceral adipose tissue, increased caloric intake, and cigarette smoking. Monogenic disorders are seen in approximately 5% of premature coronary artery disease cases, and this prevalence is higher in populations with the Founder effect. Unraveling the genetic basis of many lipoprotein disorders has allowed fundamental discoveries in molecular cellular physiology and has paved the way for novel therapeutic approaches.

Urotensin II and cardiovascular diseases

Urotensin II (UII) has been found to be a potent vasoactive peptide in humans and in a number of relevant animal models of cardiovascular disease such as the mouse, rat and other non-human primates. This peptide with structural homology to somatostatin was first isolated from the urophysis of fish and was recently found to bind to an orphan receptor in mouse and human. Initially found to have potent vasoconstrictive activities in a variety of vessels from diverse species, it has also been shown to exert vasodilatation in certain vessels in the rat and human by various endothelium-dependent mechanisms. The various vasoactive properties of UII suggest that the peptide may have a physiological role in maintaining vascular tone and therefore may have a role in the pathophysiology of a number of human diseases such as heart failure. Moreover, UII has also been implicated as a mitogen of vascular smooth muscle cells suggesting a deleterious role in atherosclerosis and coronary artery disease. In addition, there is evidence to demonstrate that UII has multiple metabolic effects on cholesterol metabolism, glycemic control and hypertension and therefore may be implicated in the development of insulin resistance and the metabolic syndrome.

Enhanced susceptibility to pulmonary infection with Burkholderia cepacia in Cftr(-/-) mice

Progressive pulmonary infection is the dominant clinical feature of cystic fibrosis (CF), but the molecular basis for this susceptibility remains incompletely understood. To study this problem, we developed a model of chronic pneumonia by repeated instillation of a clinical isolate of Burkholderia cepacia (genomovar III, ET12 strain), an opportunistic gram-negative bacterium, from a case of CF into the lungs of Cftr (m1unc-/-) (Cftr(-/-)) and congenic Cftr(+/+) controls. Nine days after the last instillation, the CF transmembrane regulator knockout mice showed persistence of viable bacteria with chronic severe bronchopneumonia while wild-type mice remained healthy. The histopathological changes in the lungs of the susceptible Cftr(-/-) mice were characterized by infiltration of a mixed inflammatory-cell population into the peribronchiolar and perivascular spaces, Clara cell hyperplasia, mucus hypersecretion in airways, and exudation into alveolar airspaces by a mixed population of macrophages and neutrophils. An increased proportion of neutrophils was observed in bronchoalveolar lavage fluid from the Cftr(-/-) mice, which, despite an increased bacterial load, demonstrated minimal evidence of activation. Alveolar macrophages from Cftr(-/-) mice also demonstrated suboptimal activation. These observations suggest that the pulmonary host defenses are compromised in lungs from animals with CF, as manifested by increased susceptibility to bacterial infection and lung injury. This murine model of chronic pneumonia thus reflects, in part, the situation in human patients and may help elucidate the mechanisms leading to defective host defense in CF.