Potential new cardiovascular risk factors: left ventricular hypertrophy, homocysteine, lipoprotein(a), triglycerides, oxidative stress, and fibrinogen

[Prognostic impact of cardiovascular risk factors in patients admitted for acute coronary syndrome]

INTRODUCTION AND OBJECTIVES

Cardiovascular prevention measures place the emphasis on controlling cardiovascular risk factors (CVRF). However, the most recent studies provide disappointing data, the impact of which remains to be determined. The objective of this study was to analyse the impact that the different CVRFs, and their degree of control, have on the prognosis of patients after acute coronary syndrome.

PATIENTS AND METHODS

Epidemiological, pharmacological, and CVRF control data were collected from 1,689 consecutive patients admitted from 2018 to 2020 for acute coronary syndrome to a tertiary hospital. Finally, the rate of major adverse cardiovascular events was calculated.

RESULTS

The patients admitted for acute coronary syndrome were predominantly men, with body mass index>25Kg/m2, smokers (or former smokers) and with poor CVRF control (50% for hypertension and diabetes and 35% for dyslipidaemia), especially those patients with a personal history of ischaemic heart disease. An underutilisation of useful drugs for CVRF control was found. A directly proportional relationship was observed between the number of CVRFs (or their poor control) and the incidence of major adverse cardiovascular events at 2 years, hypertension being the factor with the greatest cardiovascular impact. The SARS-CoV-2 lockdown worsened the degree of CVRF control and cardiovascular prognosis.

CONCLUSION

There is still room for improvement in the control of CVRF, which would translate into a prognostic benefit for patients with ischaemic heart disease. The implementation of cardiovascular prevention campaigns seems essential.

Association of lipoprotein(a) with left ventricular hypertrophy in patients with new-onset acute myocardial infarction: A large cross-sectional study

BACKGROUND

The association of lipoprotein(a) [Lp(a)] with echocardiography-estimated left ventricular hypertrophy (LVH) in high-risk population remains uncertain, so we assessed the association between Lp(a) with echocardiography-derived LVH in patients with new-onset acute myocardial infarction (AMI).

METHODS

In this large, single-center, cross-sectional observational study, we enrolled 2,096 patients with new-onset AMI. Lp(a) was used as the independent variable and LVH was used as the dependent variable. Logistic regression, subgroup and sensitivity analysis were performed to test the association of Lp(a) with LVH.

RESULTS

The concentration of Lp(a) was higher in LVH group compared with the non-LVH group (P < 0.001). Multivariate logistic regression analysis showed that higher Lp(a) was strongly associated with higher risk of LVH, independently of traditional cardiovascular risk factors (Fully adjusted model, Q4 vs Q1, OR: 1.941, 95% CI: 1.343-2.803, P < 0.001). Subgroup analysis showed that the association of Lp(a) with LVH persisted in the subgroups of age (<60 and ≥60 years), sex (male and female), smoking (yes and no), diabetes (yes), hypertension (yes), hyperlipidemia (yes), and chronic kidney diseases (yes and no). Further sensitivity analysis indicated that Lp(a) remained significantly associated with LVH after further adjusting for high-sensitivity C-reactive protein or excluding patients with estimated glomerular filtration rate < 30 ml/min/1.73 m² or dividing Lp(a) into multiple dichotomous variables.

CONCLUSION

Lp(a) was closely associated with LVH in patients with new-onset AMI.

Relationship Between Gene Polymorphism of Methylenetetrahydrofolate Reductase C677T and Left Ventricular Hypertrophy in Chinese Patients with Chronic Kidney Disease

OBJECTIVE

This study aimed to investigate the relationship between the gene polymorphism of methylenetetrahydrofolate reductase (MTHFR) C677T and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD).

METHODS

A total of 763 Chinese patients with CKD undergoing genetic testing were included in the study. The association between the gene polymorphism of MTHFR C677T and echocardiographic parameters was analyzed through univariate and multivariate analyses.

RESULTS

We found a remarkably positive association between MTHFR C677T gene polymorphism and LVH indexes, including interventricular septal thickness (F = 3.8; P = .022), left ventricular posterior wall thickness (F = 3.0; P = .052), left ventricular mass (F = 3.9; P = .022), and left ventricular mass index (F = 2.6; P = .075). After adjusting for the potential confounders linking the polymorphism,we found that the positive association between the polymorphism and LVH indexes still existed in patients with CKD in some multiple linear regression models (P <.05).

CONCLUSION

MTHFR C677T gene polymorphism may be a genetic susceptibility marker for the development of LVH in patients with CKD.

The Relationship Between Circulating Fibrinogen and Lipoprotein (a) Levels in Patients With Primary Dyslipidemia

The correlation between 2 predictors of vascular events, plasma fibrinogen and serum lipoprotein (a), was evaluated in patients referred to a specialist clinic because of primary hyperlipidemia. A significant correlation existed between fibrinogen and lipoprotein (a) in nonsmokers but not in smokers. Plasma fibrinogen concentration correlated positively and significantly with serum lipoprotein (a) levels in men nonsmokers without cardiovascular disease and in women nonsmokers with cardiovascular disease. Nonsmoker women without cardiovascular disease had significantly higher plasma fibrinogen (3.63 g/L versus 3.07 g/L, P < .0001) than the corresponding men. Nonsmoker women with and without cardiovascular disease had significantly higher lipoprotein (a) levels than the corresponding groups of men (0.36 versus 0.18 g/L; P = .0015 and 0.40 versus 0.26 g/L; P = .008), respectively. The relationship between fibrinogen and lipoprotein (a) levels alters markedly depending on the population selected. This relationship is influenced by gender, the presence of cardiovascular disease and smoking status.

A New Transgenic Mouse Model of Heart Failure and Cardiac Cachexia Raised by Sustained Activation of Met Tyrosine Kinase in the Heart

Among other diseases characterized by the onset of cachexia, congestive heart failure takes a place of relevance, considering the high prevalence of this pathology in most European countries and in the United States, and is undergoing a rapid increase in developing countries. Actually, only few models of cardiac cachexia exist. Difficulties in the recruitment and follow-up of clinical trials implicate that new reproducible and well-characterized animal models are pivotal in developing therapeutic strategies for cachexia. We generated a new model of cardiac cachexia: a transgenic mouse expressing Tpr-Met receptor, the activated form of c-Met receptor of hepatocyte growth factor, specifically in the heart. We showed that the cardiac-specific induction of Tpr-Met raises a cardiac hypertrophic remodelling, which progresses into concentric hypertrophy with concomitant increase in Gdf15 mRNA levels. Hypertrophy progresses to congestive heart failure with preserved ejection fraction, characterized by reduced body weight gain and food intake and skeletal muscle wasting. Prevention trial by suppressing Tpr-Met showed that loss of body weight could be prevented. Skeletal muscle wasting was also associated with altered gene expression profiling. We propose transgenic Tpr-Met mice as a new model of cardiac cachexia, which will constitute a powerful tool to understand such complex pathology and test new drugs/approaches at the preclinical level.

Oxidative Stress Biomarkers and Left Ventricular Hypertrophy in Children with Chronic Kidney Disease

Cardiovascular diseases remain the most frequent cause of morbidity and mortality in patients with chronic kidney disease (CKD). The aim of the study was to assess the association between oxidative stress biomarkers and cardiovascular risk factors and left ventricular hypertrophy in children with CKD. Material and Methods. The studied group consisted of 65 patients aged 1.4-18.6 (mean 11.2) years with stages 1 to 5 CKD. Serum oxidized low-density lipoprotein (oxLDL), protein carbonyl group, creatinine, cystatin C, albumin, lipids, high-sensitivity C-reactive protein, intercellular adhesion molecule-1, insulin, plasma renin activity, and aldosterone levels were measured. Patients were divided into groups depending on CKD stage. Anthropometric measurements, ambulatory blood pressure (BP) measurements, and echocardiography with left ventricular mass (LVM) calculation were performed. Results. Serum oxLDL strongly correlated with creatinine (R = 0.246; p = 0.048), cystatin C (R = 0.346; p = 0.006), total cholesterol (R = 0.500; p < 0.001), triglycerides (R = 0.524; p < 0.001), low-density lipoprotein concentrations (R = 0.456; p < 0.001), and 24 hour BP values of systolic (R = 0.492; p = 0.002), diastolic (R = 0.515; p < 0.001), and mean arterial pressure (R = 0.537; p < 0.001). A significant correlation between oxLDL levels and LVM z-scores (R = 0.299; p = 0.016) was found. Conclusions. Hypertension and dyslipidemia correlated with lipid oxidation in children with CKD. oxLDLs seem to be valuable markers of oxidative stress in CKD patients, correlating with left ventricular hypertrophy.

Additive protection by LDR and FGF21 treatment against diabetic nephropathy in type 2 diabetes model

The onset of diabetic nephropathy (DN) is associated with both systemic and renal changes. Fibroblast growth factor (FGF)-21 prevents diabetic complications mainly by improving systemic metabolism. In addition, low-dose radiation (LDR) protects mice from DN directly by preventing renal oxidative stress and inflammation. In the present study, we tried to define whether the combination of FGF21 and LDR could further prevent DN by blocking its systemic and renal pathogeneses. To this end, type 2 diabetes was induced by feeding a high-fat diet for 12 wk followed by a single dose injection of streptozotocin. Diabetic mice were exposed to 50 mGy LDR every other day for 4 wk with and without 1.5 mg/kg FGF21 daily for 8 wk. The changes in systemic parameters, including blood glucose levels, lipid profiles, and insulin resistance, as well as renal pathology, were examined. Diabetic mice exhibited renal dysfunction and pathological abnormalities, all of which were prevented significantly by LDR and/or FGF21; the best effects were observed in the group that received the combination treatment. Our studies revealed that the additive renal protection conferred by the combined treatment against diabetes-induced renal fibrosis, inflammation, and oxidative damage was associated with the systemic improvement of hyperglycemia, hyperlipidemia, and insulin resistance. These results suggest that the combination treatment with LDR and FGF21 prevented DN more efficiently than did either treatment alone. The mechanism behind these protective effects could be attributed to the suppression of both systemic and renal pathways.

Aortic unfolding determined using non-contrast cardiac computed tomography: correlations with age and coronary artery calcium score

OBJECTIVE

Aortic unfolding occurs with aging and reflects proximal aortic dilation, aortic arch widening, and decreased curvature. This study 1) evaluated the relationship between aortic unfolding measured using non-contrast cardiac-gated computed tomography (CT) and age, 2) assessed factors influencing aortic unfolding, and 3) determined the association of this measurement with coronary artery calcium (CAC) score.

METHODS

We reviewed the charts of 219 subjects (142 men, 77 women; mean age 54.2±9.3 years) who underwent coronary artery calcium scanning during routine health screening from December 2010 to May 2011. Multivariate regression analysis according to cardiovascular risk factors was performed. We also analyzed the relationship between aortic unfolding measurements and CAC score using stepwise multiple linear regression.

RESULTS

Mean aortic unfolding was 103.7±13.9 mm (men, 106.5±13.5 mm; women, 98.4±12.9 mm). Age, body surface area, and hypertension were exclusively associated with aortic unfolding. The association between aortic unfolding and CAC score was significant after adjustment for age and gender (β = 1.89, p = 0.017) and for Framingham risk score (β = 2.83, p<0.001).

CONCLUSIONS

Aortic unfolding defined by measuring aortic width was a reproducible and practical method with non-contrast cardiac CT and associated with age, body surface area, and hypertension. CAC score, a well-established surrogate marker of cardiovascular disease, is positively associated with aortic unfolding. Further study to evaluate aortic unfolding as a potential predictor of cardiovascular risk is warranted.

Multiple low-dose radiation prevents type 2 diabetes-induced renal damage through attenuation of dyslipidemia and insulin resistance and subsequent renal inflammation and oxidative stress

BACKGROUND

Dyslipidemia and lipotoxicity-induced insulin resistance, inflammation and oxidative stress are the key pathogeneses of renal damage in type 2 diabetes. Increasing evidence shows that whole-body low dose radiation (LDR) plays a critical role in attenuating insulin resistance, inflammation and oxidative stress.

OBJECTIVE

The aims of the present study were to investigate whether LDR can prevent type 2 diabetes-induced renal damage and the underlying mechanisms.

METHODS

Mice were fed with a high-fat diet (HFD, 40% of calories from fat) for 12 weeks to induce obesity followed by a single intraperitoneal injection of streptozotocin (STZ, 50 mg/kg) to develop a type 2 diabetic mouse model. The mice were exposed to LDR at different doses (25, 50 and 75 mGy) for 4 or 8 weeks along with HFD treatment. At each time-point, the kidney weight, renal function, blood glucose level and insulin resistance were examined. The pathological changes, renal lipid profiles, inflammation, oxidative stress and fibrosis were also measured.

RESULTS

HFD/STZ-induced type 2 diabetic mice exhibited severe pathological changes in the kidney and renal dysfunction. Exposure of the mice to LDR for 4 weeks, especially at 50 and 75 mGy, significantly improved lipid profiles, insulin sensitivity and protein kinase B activation, meanwhile, attenuated inflammation and oxidative stress in the diabetic kidney. The LDR-induced anti-oxidative effect was associated with up-regulation of renal nuclear factor E2-related factor-2 (Nrf-2) expression and function. However, the above beneficial effects were weakened once LDR treatment was extended to 8 weeks.

CONCLUSION

These results suggest that LDR exposure significantly prevented type 2 diabetes-induced kidney injury characterized by renal dysfunction and pathological changes. The protective mechanisms of LDR are complicated but may be mainly attributed to the attenuation of dyslipidemia and the subsequent lipotoxicity-induced insulin resistance, inflammation and oxidative stress.

Dialysis patients and cardiovascular problems: can technology solve the complex equation?

Patients with end-stage kidney disease undergoing chronic hemodialysis present higher mortality rates compared with the general population. Once patients are on hemodialysis, the risk of cardiovascular death is approximately 30-times higher than the general population, and still remains 10- to 20-times higher after stratification for age, gender and presence of diabetes. Approximately half of patient deaths on dialysis are attributed to cardiovascular causes, including coronary heart disease, cerebrovascular disease, peripheral vascular disease and heart failure. The cardiovascular burden of the hemodialysis patient arises from three different sources: risks inherent to the patient and the uremic syndrome, traditional risk factors and risk factors related to the dialysis therapy. Based on these considerations and the fact that several aspects of the dialysis procedure can cause either a cardiovascular burden or modify the burden already present, new technologies should be directed towards the approach of a possible 'cardioprotective dialysis therapy'. This approach may significantly contribute new techniques and new dialysis machines. Born to make dialysis easy and safe, the new machines feature several options that make monitoring and online hemodiafiltration a simple routine. These and other features could make dialysis better tolerated and more efficient in protecting from fatal cardiovascular events.

The effect of bisphenol A on some oxidative stress parameters and acetylcholinesterase activity in the heart of male albino rats

Bisphenol A (BPA) is an endocrine disrupting chemical used on a wide range in industry. Several studies reported that BPA may cause cardiovascular disorders in humans and animals. The present study aims to investigate the effect of BPA on the heart of adult male rats. The rats received a daily oral administration of BPA (25 mg/kg for 6 weeks and 10 mg/kg for 6 and 10 weeks). It was found that BPA at the two studied doses induced a significant increase in malondialdehyde, and a significant decrease in catalase after 6 weeks. Moreover, a significant decrease in reduced glutathione and acetylcholinesterase (AchE) activity was observed after treatment with the two doses of BPA throughout the studied time intervals. The two doses (25 and 10 mg/kg) resulted in a significant decrease in nitric oxide (NO) levels after 6 and 10 weeks, respectively. A significant increase in body weight gain occurred in all animals after BPA treatment. These results suggest that BPA has cardiotoxic effects which are mediated by the oxidative stress resulting from the overproduction of free radicals, the deficiency of NO and the inhibition of AchE leading to cholinergic activation. The obesity promoting effect of BPA may also participate in the observed cardiovascular disturbances.

The value of apolipoprotein B/A1 ratio in the diagnosis of metabolic syndrome in a Korean population

OBJECTIVE

The ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1) has been reported to be associated with the metabolic syndrome (MetS). However, the optimal cut-off value of apoB/A1 ratio for detecting subjects with MetS has remained undetermined. In the present study, we aimed to investigate whether apoB/A1 ratio can be an indicator of MetS and to determine the optimal cut-off value of apoB/A1 ratio in detecting subjects with MetS in a Korean population.

DESIGN

This cross-sectional study was conducted at the Asan Medical Center, Seoul, Republic of Korea.

SUBJECTS AND MEASUREMENTS

We collected the data of 10,940 subjects who participated in a routine health screening examination regarding conventional risk factors and serum levels of apoB and apoA1.

RESULTS

The odds for MetS were significantly higher in the highest compared with the lowest apoB/A1 ratio quartiles, after adjustment for confounding variables, in both men [odds ratio (OR) = 4·07, 95% CI = 3·42-4·84] and women (OR = 8·41, 95% CI = 5·85-12·08). The optimal apoB/A1 ratio cut-off value for the detection of MetS was 0·65, which had a sensitivity of 63·5% and a specificity of 61·3% (area under the curve = 0·67, 95% CI = 0·66-0·68, P < 0·001) in men and 0·62, which had a sensitivity of 67·9% and a specificity of 61·9% (area under the curve = 0·70, 95% CI = 0·69-0·71, P < 0·001) in women.

CONCLUSIONS

These results suggest that apoB/A1 ratio is independently associated with MetS and that an apoB/A1 ratio >0·65 in men and 0·62 in women is a marker of MetS independent from conventional risk factors.

The Correlation Between Small Dense LDL and Reactive Oxygen Metabolites in a Physical Activity Intervention in Hyperlipidemic Subjects

Background

Small dense low-density lipoprotein (sdLDL), which has a small LDL particle size with a greater susceptibility to oxidation, is considered a risk marker for cardiovascular disease (CVD). The diacron reactive oxygen metabolites (d-ROMs) have recently been introduced as a clinically useful oxidative stress-related marker. Physical activity can reduce the CVD risk. The present study investigated the correlation between the changes of the mean LDL particle size and the oxidative stress status, as assessed by the d-ROMs, in a physical activity intervention in hyperlipidemic subjects.

Methods

We performed a 6-month intervention study of 30 hyperlipidemic subjects (12 male/18 female, mean age 64 years), focusing on a moderate physical activity increase. The clinical data, including the atherosclerotic risk factors besides the mean LDL particle size measured with the gel electrophoresis and the d-ROMs, were evaluated pre- and post-intervention.

Results

The mean LDL particle size was significantly larger in the post-intervention than in the pre-intervention evaluation (26.9 ± 0.3 (SD) vs. 27.1 ± 0.4 nm, P < 0.01), while the d-ROMs levels were significantly reduced in the post-intervention period compared to those at pre-intervention (319 ± 77 vs. 290 ± 73 U. Carr., P < 0.05). A stepwise multiple regression analysis revealed that there was an independent, significant and inverse correlation between the pre- and post-intervention changes of the d-ROMs and the mean LDL particle size (β = -0.55, P < 0.01).

Conclusions

The intervention study suggests that sdLDL and oxidative stress can concomitantly affect the risk of developing CVD and that both factors can improve by even a moderate increase in physical activity among hyperlipidemic subjects.

Ameliorate Effects of Li-Fu Formula on IL-6-Mediated Cardiac Hypertrophy in Hamsters Fed with a Hyper-Cholesterol Diet

Hypercholesterolemia diets are considered as major sources to cause cardiac hypertrophy. This study intends to evaluate the effects of Li-Fu formula on cardiac hypertrophy induced by hypercholesterolemia diet. Twenty-four male Golden Syrian hamsters were randomly divided into control, cholesterol and Li-Fu formula groups and fed with different experimental diets for 2 months. Histopathological analysis and western blotting were performed to measure the myocardial architecture, and various cardiac hypertrophy-associated molecules in the excised left ventricle from hamsters. The ratios of whole heart weight/body weight (BW) and left ventricle weight/BW were significantly higher in the cholesterol group but significantly lower in the Li-Fu formula group. The protein levels of both atrial natriuretic peptide and brain natriuretic peptide were significantly increased in the cholesterol group but significantly reduced in the Li-Fu formula group. Additionally, significantly increased interleukin-6, STAT3, MEK5, p-ERK5 and non-cardiomyocyte proliferate signal molecules such as p-MEK and p-ERK, were detected in the cholesterol group but significantly reduced in the Li-Fu formula group. Notably, no significant variations of inflammatory signaling molecules, including p-P38 and p-JNK, were detected in all groups. Our experimental results demonstrated the significant reductions of cardiac hypertrophy and related eccentric hypertrophy signaling, non-cardiomyocyte proliferate signaling in the excised left ventricle of hamsters from the Li-Fu formula. We suggested the protective effects of Li-Fu formula on cardiac hypertrophy that may be useful in prevention or treatment of hypertrophy-associated cardiovascular diseases.

Attenuated cardiac mitochondrial-dependent apoptotic effects by li-fu formula in hamsters fed with a hypercholesterol diet

Apoptosis involves in the pathogenesis of various cardiac abnormalities. This study intends to evaluate the effects of Li-Fu formula on cardiac apoptosis induced by hyper-cholesterol diet. Twenty-four male Golden Syrian hamsters were randomly divided into Control, Cholesterol and Li-Fu formula groups. Histopathological analysis, western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to measure the effects of Li-Fu formula on left ventricle. Significantly reduced TUNEL-positive cells and mitochondria- dependent apoptosis were observed in the left ventricle of hamsters from Li-Fu formula group compared to the Cholesterol group. Additionally, induced cardiac insulin like growth factor I receptor (IGFIR)-dependent survival pathway was detected in the Li-Fu formula group compared to the Cholesterol group. Besides, minor fibrosis, increased collagen deposition, and myofibril disarray was detected in the Cholesterol group, whereas the reductions of collagen deposition and myofibril disarray were observed in the Li-Fu formula group. This study demonstrated that Li-Fu formula not only reduced the mitochondria-dependent apoptosis and fibrosis, but also enhanced the IGF-I survival pathway in the left ventricle from high cholesterol-fed hamsters. We suggest the protective effects of Li-Fu formula on cardiac apoptosis and therapeutic potentials against cardiovascular disease.

Effect of highly active antiretroviral therapy on homocysteine plasma concentrations in HIV-1-infected patients

OBJECTIVE

To analyze the effect of antiretroviral therapy on homocysteine levels in HIV-1-infected patients.

DESIGN

Observational, prospective study of patients with AIDS.

METHODS

We included patients with HIV-1 infection naive for antiretroviral drugs. Before and after 6 months of treatment, we evaluated fasting and postoral methionine load plasma homocysteine, serum vitamins B6 and B12, and intraerythrocyte folate levels.

RESULTS

We studied 69 patients who began therapy for a 6-month period. Fasting and postoral methionine load plasma homocysteine levels increased significantly after 6 months of antiretroviral therapy with respect to basal values (P < 0.001). Fasting hyperhomocysteinemia was present in 7.3% of patients before treatment and in 89.9% after 6 months of therapy (P = 0.0001). Postoral methionine load hyperhomocysteinemia was found in 4.5% of subjects before therapy vs. 98.5% at the end of study period (P = 0.001). These results were not associated with folate or vitamins B6 or B12 levels.

CONCLUSIONS

In patients with HIV-1 infection, fasting and postoral methionine load plasma homocysteine levels increased after 6 months of antiretroviral treatment. Nutritional abnormalities were not responsible for hyperhomocysteinemia, suggesting that enzymatic disturbances in the metabolic pathways of homocysteine may occur.

The role of fibrinogen in aggregation of platelets in burn injury

Spontaneous aggregation of platelets is considerably enhanced in the acute period after burn. The changes in indices-induced aggregation of platelets are non-uniform and not significant statistically. Thermal trauma is accompanied by the development of hyperfibrinogenemia and an increase in the level of oxidised fibrinogen. We studied the influence of fibrinogen concentration and the degree of its oxidation on aggregation of platelets. It was shown that the level of aggregation of platelets greatly depends on the concentration of fibrinogen (non-oxidised and oxidised) plasma. The possible mechanisms of these effects are investigated.

Pulmonary oxidative stress, inflammation, and dysregulated iron homeostasis in rat models of cardiovascular disease

Underlying cardiovascular disease (CVD) is a risk factor for the exacerbation of air pollution health effects. Pulmonary oxidative stress, inflammation, and altered iron (Fe) homeostasis secondary to CVD may influence mammalian susceptibility to air pollutants. Rodent models of CVD are increasingly used to examine mechanisms of variation in susceptibility. Baseline cardiac and pulmonary disease was characterized in healthy normotensive Wistar Kyoto (WKY) rats, cardiovascular compromised spontaneously hypertensive rats (SHR), and spontaneously hypertensive heart failure (SHHF) rats. Blood pressure, heart rate, and breathing frequencies were measured in rats 11 to 12 wk of age, followed by necropsy at 14 to 15 wk of age. Blood pressure and heart rate were increased in SHR and SHHF relative to WKY rats (SHR > SHHF > WKY). Increased breathing frequency in SHHF and SHR (SHR > SHHF > WKY) resulted in greater minute volume relative to WKY. Bronchoalveolar lavage fluid (BALF) protein and neutrophils were higher in SHHF and SHR relative to WKY (SHHF >> SHR > WKY). Lung ascorbate and glutathione levels were low in SHHF rats. BALF Fe-binding capacity was decreased in SHHF relative to WKY rats and was associated with increased transferrin (Trf) and ferritin. However, lung ferritin was lower and Trf was higher in SHHF relative to WKY or SHR rats. mRNA for markers of inflammation and oxidative stress (macrophage inflammatory protein [MIP]-2, interleukin [IL]-1alpha, and heme oxygenase [HO]-1) were greater in SHHF and SHR relative to WKY rats. Trf mRNA rose in SHR but not SHHF relative to WKY rats, whereas transferrin receptors 1 and 2 mRNA was lower in SHHF rats. Four of 12 WKY rats exhibited cardiac hypertrophy despite normal blood pressure, while demonstrating some of the pulmonary complications noted earlier. This study demonstrates that SHHF rats display greater underlying pulmonary complications such as oxidative stress, inflammation, and impaired Fe homeostasis than WKY or SHR rats, which may play a role in SHHF rats' increased susceptibility to air pollution.

An elevated level of physical activity is associated with normal lipoprotein(a) levels in individuals from Maracaibo, Venezuela

Coronary artery disease is the main cause of death worldwide. Lipoprotein(a) [Lp(a)], is an independent risk factor for coronary artery disease in which concentrations are genetically regulated. Contradictory results have been published about physical activity influence on Lp(a) concentration. This research aimed to determine associations between different physical activity levels and Lp(a) concentration. A descriptive and cross-sectional study was made in 1340 randomly selected subjects (males = 598; females = 712) to whom a complete clinical history, the International Physical Activity Questionnaire, and Lp(a) level determination were made. Statistical analysis was carried out to assess qualitative variables relationship by chi2 and differences between means by one-way analysis of variance considering a P value <0.05 as statistically significant. Results are shown as absolute frequencies, percentages, and mean +/- standard deviation according to case. Physical activity levels were ordinal classified as follows: low activity with 24.3% (n = 318), moderate activity with 35.0% (n = 458), and high physical activity with 40.8% (n = 534). Lp(a) concentration in the studied sample was 26.28 +/- 12.64 (IC: 25.59-26.96) mg/dL. Lp(a) concentration according to low, moderate, and high physical activity levels were 29.22 +/- 13.74, 26.27 +/- 12.91, and 24.53 +/- 11.35 mg/dL, respectively, observing statistically significant differences between low and moderate level (P = 0.004) and low and high level (P < 0.001). A strong association (chi2 = 9.771; P = 0.002) was observed among a high physical activity level and a normal concentration of Lp(a) (less than 30 mg/dL). A lifestyle characterized by high physical activity is associated with normal Lp(a) levels.

Plasma homocysteine in adolescents depends on the interaction between methylenetetrahydrofolate reductase genotype, lipids and folate: a seroepidemiological study

Background

Many publications link high homocysteine levels to cardiovascular disease. In Spain there is little information on the prevalence of hyperhomocysteinaemia and associated vitamin factors among the general population, and less still among children. Cardiovascular risk factors in the childhood population may be related to the appearance of cardiovascular disease at adult age. The aim of this study is to establish a definition of hyperhomocysteinaemia in adolescents and to analyze the influence of vitamin and metabolic factors in homocysteine levels in this population group.

Methods

Descriptive, cross-sectional epidemiological study to estimate serum homocysteine, vitamin B12 and folate levels, as well as plasma total, HDL- and LDL- cholesterol in a schoolgoing population aged 13 to 17 years in Madrid, Spain.

Spearman correlation analysis was performed to ascertain quantitative comparison, Pearson's χ2 test (frequency < 5, Fisher) was used for comparison of prevalences, Mann-Whitney U and Kruskal-Wallis test were used for comparison of means and Bonferroni correction was used for post-hoc tests. A multivariate logistic regression model was performed in the multivariate analysis.

Results

Based on the classic values for definition of hyperhomocysteinaemia in adults, prevalence of hyperhomocysteinaemia in the study population was: 1.26% for 15 μmol/L; and 2.52% for 12 μmol/L.

Deficits in HDL cholesterol and serum folate levels yielded adjusted Odds Ratios (OR) for hyperhomocysteinemia of 2.786, 95% CI (1.089-7.126), and 5.140, 95% CI (2.347-11.256) respectively. Mutation of the methylenetetrahydrofolate reductase (MTHFR) C677T genotype also raises the risk of hyperhomocysteinaemia (CC→CT: OR = 2.362; 95% CI (1.107-5.042) CC→TT: OR = 6.124, 95% CI (2.301-16.303))

Conclusion

A good definition of hyperhomocysteinaemia in adolescents is the 90^th percentile, equivalent to 8.23 μmol/L. Risk factors for hyperhomocysteinaemia are cHDL and folate deficiency, and the MTHFR C677T mutant genotype. No significant effect could be assessed for vitamin B₁₂. Coexistence of all three factors increases the risk of suffering from hyperhomocysteinaemia 87-fold.

Repeatability and measurement error in the assessment of choline and betaine dietary intake: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

The repeatability of a risk factor measurement affects the ability to accurately ascertain its association with a specific outcome. Choline is involved in methylation of homocysteine, a putative risk factor for cardiovascular disease, to methionine through a betaine-dependent pathway (one-carbon metabolism). It is unknown whether dietary intake of choline meets the recommended Adequate Intake (AI) proposed for choline (550 mg/day for men and 425 mg/day for women). The Estimated Average Requirement (EAR) remains to be established in population settings. Our objectives were to ascertain the reliability of choline and related nutrients (folate and methionine) intakes assessed with a brief food frequency questionnaire (FFQ) and to estimate dietary intake of choline and betaine in a bi-ethnic population.

METHODS

We estimated the FFQ dietary instrument reliability for the Atherosclerosis Risk in Communities (ARIC) study and the measurement error for choline and related nutrients from a stratified random sample of the ARIC study participants at the second visit, 1990-92 (N = 1,004). In ARIC, a population-based cohort of 15,792 men and women aged 45-64 years (1987-89) recruited at four locales in the U.S., diet was assessed in 15,706 baseline study participants using a version of the Willett 61-item FFQ, expanded to include some ethnic foods. Intraindividual variability for choline, folate and methionine were estimated using mixed models regression.

RESULTS

Measurement error was substantial for the nutrients considered. The reliability coefficients were 0.50 for choline (0.50 for choline plus betaine), 0.53 for folate, 0.48 for methionine and 0.43 for total energy intake. In the ARIC population, the median and the 75th percentile of dietary choline intake were 284 mg/day and 367 mg/day, respectively. 94% of men and 89% of women had an intake of choline below that proposed as AI. African Americans had a lower dietary intake of choline in both genders.

CONCLUSION

The three-year reliability of reported dietary intake was similar for choline and related nutrients, in the range as that published in the literature for other micronutrients. Using a brief FFQ to estimate intake, the majority of individuals in the ARIC cohort had an intake of choline below the values proposed as AI.

Measurement of left ventricular mass by contrast ventriculography

BACKGROUND

Elevated left ventricular mass (LVM) has been shown to be an important predictor of adverse cardiac events. Calculation of LVM using contrast ventriculography, as described by Rackley, involves measuring left ventricular wall thickness in a single plane, with assumptions made about ventricular geometry.

HYPOTHESIS

We hypothesized that a modification of the Rackley method, involving multiple measurements of left ventricular (LV) wall thickness in 2 orthogonal planes, may add value in the determination of LVM in patients with LV remodeling and dysfunction.

METHODS

The LVM was determined in 24 patients with LV dysfunction who had undergone both cardiac magnetic resonance imaging (CMRI) and contrast left ventriculography. Right anterior oblique (RAO) and left anterior oblique (LAO) still frames in diastole were used to measure LV length, chamber area, and wall thickness. From these variables, LV volume, myocardial volume, and LVM were calculated. The LVM calculations using an average wall thickness from the LAO and RAO projections were compared with LVM measured by CMRI.

RESULTS

Eighty eight percent of patients had hypertension, 100% had coronary artery disease, and mean left ventricular ejection fraction by contrast left ventriculography was 41 +/- 14%. Averaging left ventricular wall thickness from RAO and LAO projections using biplane ventriculography for LVM calculation yielded a strong correlation (r = 0.77, p < 0.01) with LVM calculated from CMR.

CONCLUSIONS

In patients with left ventricular dysfunction, biplane left ventricular wall thickness measurements for contrast ventriculography LVM calculations render a strong correlation with LVM calculated by CMRI.

Action Schools! BC: a school-based physical activity intervention designed to decrease cardiovascular disease risk factors in children

OBJECTIVE

Our primary objective was to determine whether a novel 'active school' model--Action Schools! BC--improved the cardiovascular disease (CVD) risk profile in elementary-school children. Our secondary objective was to determine the percentage of children with elevated CVD risk factors.

METHODS

We undertook a cluster-randomized controlled school-based trial with 8 elementary schools across 1 school year, in British Columbia, Canada, beginning in 2003. Boys and girls (n=268, age 9-11 years) were randomly assigned (by school) to usual practice (UP, 2 schools) or intervention (INT, 6 schools) groups. We assessed change between groups in cardiovascular fitness (20-m Shuttle Run), blood pressure (BP), and body mass index (BMI, wt/ht(2)). We evaluated total cholesterol (TC), total:high-density cholesterol (TC:HDL-C), low-density lipoprotein, apolipoprotein B, C-reactive protein and fibrinogen on a subset of volunteers (n=77).

RESULTS

INT children had a 20% greater increase in fitness and a 5.7% smaller increase in BP compared with children attending UP schools (P<0.05). Forty five percent of children had at least one elevated risk factor (fitness, BP or BMI) at baseline. There were no significant differences between groups for change in BMI or in any of the blood variables.

CONCLUSION

Action Schools! BC was an effective school-based physical activity model for improving the CVD risk profile of elementary-school children. Our multi-component intervention exposed children to fitness enhancing physical activity. It may be important for education stakeholders to adequately resource the delivery of the active school models if cardiovascular health benefits are to be achieved on a population basis.

Assessment of lower limb ischemia with measurement of skin perfusion pressure in patients on hemodialysis

Measurement of skin perfusion pressure (SPP) using laser Doppler has become available for the assessment of peripheral arterial disease. We studied whether measurements of SPP can be used to identify hemodialyzed patients with peripheral arterial disease by comparing it with measurements of the ankle brachial pressure index (ABI). The ABI at rest and the SPP in the foot were measured in 59 Japanese hemodialyzed patients (118 limbs). Twenty-one patients had diabetes mellitus. Five had intermittent claudication; however, 20 patients were accompanied by other exertional leg symptoms. The SPP could not be measured in three limbs because of involuntary movement due to previous stroke or restless leg syndrome. The SPP was correlated with the ABI. Depending upon these results of the ABI, the 114 limbs from which both the ABI and the SPP could measured were divided into three groups: (A) ABI > or = 1.3, (B) 0.9 < or = ABI < 1.3, and (C) ABI < 0.9. The average SPP of group C was significantly decreased among the three groups. All subjects of the three groups were divided into an extra two groups according to the presence of diabetes (non-diabetes groups, -I; diabetes groups, -II). The average SPP of group B-II was significantly decreased compared with those of group B-I. The SPP measurement is a noninvasive, useful screening method for limb ischemia that can be applied to exercise tolerance limited patients. The SPP measurements are expected to be useful for the evaluation of limb ischemia in hemodialyzed patients at risk.

Roles of amyloid beta-peptide-associated oxidative stress and brain protein modifications in the pathogenesis of Alzheimer's disease and mild cognitive impairment

Oxidative stress has been implicated to play a crucial role in the pathogenesis of a number of diseases, including neurodegenerative disorders, cancer, and ischemia, just to name a few. Alzheimer disease (AD) is an age-related neurodegenerative disorder that is recognized as the most common form of dementia. AD is histopathologically characterized by the presence of extracellular amyloid plaques, intracellular neurofibrillary tangles, the presence of oligomers of amyloid beta-peptide (Abeta), and synapse loss. In this review we discuss the role of Abeta in the pathogenesis of AD and also the use of redox proteomics to identify oxidatively modified brain proteins in AD and mild cognitive impairment. In addition, redox proteomics studies in in vivo models of AD centered around human Abeta(1-42) are discussed.

A coronary heart disease risk model for predicting the effect of potent antiretroviral therapy in HIV-1 infected men

BACKGROUND

Many HIV-infected patients on highly active antiretroviral therapy (HAART) experience metabolic complications including dyslipidaemia and insulin resistance, which may increase their coronary heart disease (CHD) risk. We developed a prognostic model for CHD tailored to the changes in risk factors observed in patients starting HAART.

METHODS

Data from five cohort studies (British Regional Heart Study, Caerphilly and Speedwell Studies, Framingham Offspring Study, Whitehall II) on 13,100 men aged 40-70 and 114,443 years of follow up were used. CHD was defined as myocardial infarction or death from CHD. Model fit was assessed using the Akaike Information Criterion; generalizability across cohorts was examined using internal-external cross-validation.

RESULTS

A parametric model based on the Gompertz distribution generalized best. Variables included in the model were systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, triglyceride, glucose, diabetes mellitus, body mass index and smoking status. Compared with patients not on HAART, the estimated CHD hazard ratio (HR) for patients on HAART was 1.46 (95% CI 1.15-1.86) for moderate and 2.48 (95% CI 1.76-3.51) for severe metabolic complications.

CONCLUSIONS

The change in the risk of CHD in HIV-infected men starting HAART can be estimated based on typical changes in risk factors, assuming that HRs estimated using data from non-infected men are applicable to HIV-infected men. Based on this model the risk of CHD is likely to increase, but increases may often be modest, and could be offset by lifestyle changes.

Lipoprotein(a) as a risk factor associated with ischemic heart disease: Ouro Preto Study

Evidences suggest that lipoprotein(a) [Lp(a)] is an important risk factor for cardiovascular disease. However, literature has been controversial in confirming its role as an independent risk factor for cardiovascular disease. The objective of the present study is to evaluate the association between serum levels of Lp(a) and ischemic heart disease as well as other cardiovascular risk factors in a population-based study conducted on a local cohort of the Brazilian population. Lp(a) serum levels were measured in 400 individuals selected from a larger sample of a populational survey carried out in Ouro Preto, a city in the southeast of Brazil. Lipid profile, fasting blood glucose, anthropometric and clinical parameters were analyzed. Lp(a) levels were significantly associated with the presence of ischemic heart disease. In relation to other cardiovascular risk factors, it was verified that Lp(a) levels were statistically associated with age, total cholesterol, LDL-cholesterol and percentage of body fat determined by bioelectric impedance. Lp(a) was also highly associated with the Framingham risk score (p=0.003). In a multivariate analysis two significant interactions were revealed; one involving ischemic heart disease, sex and age and other associating ischemic heart disease, age and total cholesterol. In summary, in the present analysis Lp(a) serum levels were correlated with the occurrence of ischemic heart disease and other cardiovascular risk factors.

Gene–nutrient interactions: dietary behaviour associated with high coronary heart disease risk particularly affects serum LDL cholesterol in apolipoprotein E ε4-carrying free-living individuals

Apolipoprotein E (ApoE) genotype influence on the relationship between dietary risk factors for cardiovascular disease and blood serum lipid levels was investigated in 132 free-living individuals participating in the European Prospective Investigation of Cancer (EPIC) study. All subjects (age 40–69) were clinically healthy and provided information on their usual diet. ApoE genotype and serum lipid concentrations were determined in all subjects. Relationships of intake of dietary constituents with serum lipid levels were compared in different genotype groups. There was a significant correlation between total serum cholesterol and intake of energy derived from total fat (r 0·195; P 0·025) and saturated fat (r 0·174; P 0·046) in the cohort as a whole. However, individuals with the ApoE ε3/ε4 genotype displayed a much stronger positive correlation between LDL cholesterol level and the percentage of energy derived from intake of saturated fat (r 0·436; P 0·043). There were no significant associations in the groups with ε3/ε3 or ε2/ε2 & ε2/ε3 genotype. A significant positive correlation between alcohol consumption and HDL cholesterol level was present in individuals bearing ApoE ε2 allele. These findings support current public health recommendations that saturated fat consumption should be reduced in order to reduce coronary heart disease risk. Total cholesterol concentrations were positively related to saturated fat intake in the cohort as a whole, but elevated LDL cholesterol levels associated with high saturated fat intake can be expected particularly in those individuals who combine a ‘risky’ dietary behaviour with the presence of the ε4 variant of ApoE.

Cardiovascular complications of obesity in adolescents

Obesity is an increasingly important worldwide health problem, representing the major risk factor for coronary heart disease. The increase in the prevalence of obesity, particularly among younger age groups, is likely to have long-term implications for cardiovascular disease (CVD) in the years to come, especially at a young age. Obesity plays a central role in the insulin resistance (IR) syndrome and increases the risk of atherosclerotic CVD. The present review will examine the relationships among cardiovascular risk (CVR) factors during the childhood-adolescence-adulthood transition. In fact, the relation between obesity, in particular visceral obesity and CVD, appears to develop at a relatively young age. The foremost physical consequence of obesity is atherosclerotic CVD, and an intriguing example of obesity-related cardiovascular complications affecting young women is the polycystic ovary syndrome (PCOS).

Additive value of immunoassay-measured fibrinogen and high-sensitivity C-reactive protein levels for predicting incident cardiovascular events

BACKGROUND

Current guidelines suggest measuring high-sensitivity C-reactive protein (hs-CRP) as an aid to coronary risk assessment in adults without cardiovascular disease (CVD). Whether other inflammatory biomarkers, such as fibrinogen, add further prognostic information is uncertain.

METHODS AND RESULTS

In a prospective study of 27,742 initially healthy middle-aged women, the associations of baseline immunoassay fibrinogen and hs-CRP measurements with incident CVD were examined over a 10-year follow-up period. Compared with women in the bottom biomarker quintile, age-adjusted hazard ratios (95% confidence intervals [CIs]) for incident CVD for quintiles 2 to 5 of fibrinogen were 1.10 (0.86 to 1.41), 1.30 (1.03 to 1.65), 1.46 (1.16 to 1.85), and 2.43 (1.95 to 3.02); for hs-CRP they were 1.48 (1.06 to 2.05), 1.70 (1.24 to 2.33), 2.20 (1.63 to 2.96), and 3.24 (2.43 to 4.31). After further adjustment for established risk factors, both biomarkers remained associated (P for trend < or = 0.001) with incident CVD (hazard ratio, 1.35; 95% CI, 1.07 to 1.71 for top fibrinogen quintile; and hazard ratio, 1.68; 95% CI, 1.22 to 2.29 for top hs-CRP quintile compared with the bottom quintiles). Further adjustment for the other biomarker resulted in hazard ratios of 1.23 and 1.56 (P for trend = 0.02 and 0.002), respectively. Although fibrinogen correlated positively with hs-CRP (rs = 0.41, P < 0.001), the highest CVD risk was associated with elevated levels of both fibrinogen and hs-CRP: age-adjusted hazard ratio of 3.45 (95% CI, 2.60 to 4.57) for women with fibrinogen > 393 mg/dL and hs-CRP > 3 mg/L compared with < 329 mg/dL and < 1 mg/L, respectively.

CONCLUSIONS

In this cohort of initially healthy women, baseline levels of fibrinogen measured with a high-quality immunoassay provided additive value to hs-CRP and traditional risk factors in predicting incident CVD.

Cardiovascular risk in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is not only a reproductive problem but a complex, endocrine, multifaceted disease with several health complications. Cardiovascular abnormalities represent important long-term sequelae of PCOS.

Building prediction models for coronary heart disease by synthesizing multiple longitudinal research findings

BACKGROUND

No methodology is currently available to allow the combining of individual risk factor information derived from different longitudinal studies for a chronic disease in a multivariate fashion. This paper introduces such a methodology, named Synthesis Analysis, which is essentially a multivariate meta-analytic technique.

DESIGN

The construction and validation of statistical models using available data sets.

METHODS AND RESULTS

Two analyses are presented. (1) With the same data, Synthesis Analysis produced a similar prediction model to the conventional regression approach when using the same risk variables. Synthesis Analysis produced better prediction models when additional risk variables were added. (2) A four-variable empirical logistic model for death from coronary heart disease was developed with data from the Framingham Heart Study. A synthesized prediction model with five new variables added to this empirical model was developed using Synthesis Analysis and literature information. This model was then compared with the four-variable empirical model using the first National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study data set. The synthesized model had significantly improved predictive power (chi = 43.8, P<0.00001).

CONCLUSIONS

Synthesis Analysis provides a new means of developing complex disease predictive models from the medical literature.

Acromegaly and the cardiovascular system

Acromegaly is characterized by an increased cardiovascular morbidity and mortality. In fact, growth hormone and insulin-like growth factor-I excess induces a specific cardiomyopathy. The heart is involved from the very early stages of the disease in which the hyperkinetic syndrome (high heart rate and increased systolic output) takes place. Frequently, if the disease is untreated for many years or unsuccessfully treated, concentric biventricular hypertrophy and diastolic dysfunction can develop and, at least, lead to diastolic congestive heart failure. Rhythm disturbances and valve dysfunction are also frequently described in acromegaly. The coexistence of other complications, such as diabetes and arterial hypertension, can induce the worsening of acromegalic cardiomyopathy. Control of acromegaly by surgery or pharmacotherapy could improve cardiovascular morbidity thanks to decreasing left ventricular mass and reducing cardiac dysfunction. In conclusion, an early diagnosis and a careful evaluation of cardiac function, morphology and activity seem to be mandatory in acromegaly.

Dialysis Patients and Cardiovascular Problems: Can Technology Help Solve the Complex Equation?

Patients with end-stage kidney disease undergoing chronic hemodialysis (HD) present higher mortality rates compared with the general population. Once patients are on HD, the risk of cardiovascular death is approximately 30 times higher than in the general population and remains 10-20 times higher after stratification for age, gender, and the presence of diabetes. About half the deaths of patients on dialysis are attributed to cardiovascular causes including coronary heart disease, cerebrovascular disease, peripheral vascular disease, and heart failure. The cardiovascular burden of the HD patient arises from three different sources: risks inherent to the patient and the uremic syndrome, traditional risk factors, and risk factors related to the dialysis therapy. Based on these considerations and the fact that several aspects of the dialysis procedure can either add to the cardiovascular burden or modify the existing burden, new technologies should be directed towards the approach of a potential 'cardioprotective dialysis therapy'; such an approach may be facilitated by the application of new techniques and advanced dialysis machines. Created to make dialysis easy and safe, new machines feature several options that make patient monitoring and online hemodiafiltration therapy routine procedures. These and other features will possibly make dialysis better tolerated and more efficient in protecting patients from undesirable or potentially fatal cardiovascular events.

Cardiovascular alteration and treatment of hypertension: do men and women differ?

Cardiovascular disease is one of the most common causes of mortality affecting both men and women in industrialized nations. Sex-related differences have been well established with regard to heart and vascular function as well as cardiovascular disease processes. Nevertheless, the precise mechanisms of action behind these gender-related differences are poorly understood. Premenopausal women have a relatively lower arterial blood pressure compared to age-matched men and post-menopausal women, suggesting a role of ovarian hormones in blood pressure regulation. Sex-related differences in vasculature and neuroendocrine systems are also present that can affect hemostasis, vascular reactivity, and vascular tone. Treatment for cardiovascular disease and hypertension has been challenging and unsatisfactory. Men and women may require different antihypertensive regimens due to differences in the progression and presentation of hypertension. Additionally, hormone replacement therapy in postmenopausal women has been controversial, producing both beneficial and detrimental effects. Therefore, this review will focus on sex-related differences in the heart and vasculature, and treatments for cardiovascular disease, such as hypertension.

No association between pulmonary embolism or deep vein thrombosis and the -455G/A beta-fibrinogen gene polymorphism

Hyperfibrinogenaemia has been reported to be associated with deep vein thrombosis (DVT). However, whether or not the "fibrinogen-raising"-455G/A polymorphism of the beta-fibrinogen gene is associated with DVT is uncertain and there are no data on whether this polymorphism is associated with pulmonary embolism (PE). We have studied relationships between the -455G/A beta-fibrinogen gene polymorphism and the occurrence of PE and/or DVT (n = 339) (PE only, n = 76; DVT only, n = 216; PE and DVT, n = 47). There was no difference between the -455A allelic frequencies for the control (n = 190) and patient groups - PE, 0.187 and 0.171, respectively [P = 0.6087, chi test; odds ratio (OR), 1.12; 95% confidence interval (CI), 0.72-1.74]; DVT, 0.187 and 0.171, respectively (P = 0.5408, chi test; OR, 1.11; 95% CI, 0.78-1.59). This also applied when only Caucasian individuals were considered - PE allelic frequencies, 0.192 and 0.193, respectively (P = 0.9764, chi test; OR, 0.99; 95% CI, 0.62-1.60); DVT allelic frequencies, 0.192 and 0.186, respectively (P = 0.8404, chi test; OR, 1.04; 95% CI, 0.71-1.51). While the results should be interpreted with caution as the frequency of the -455A allele is rare, the -455A allele of the beta-fibrinogen gene does not appear to be associated with an increased risk of PE or DVT.

Traditional and non-traditional risk factors as contributors to atherosclerotic cardiovascular disease in end-stage renal disease

Cardiovascular disease (CVD) remains the main cause of morbidity and mortality in patients with end-stage renal disease (ESRD). Although traditional risk factors, such as diabetes mellitus, hypertension, dyslipidemia and advanced age, are prevalent in ESRD patients they may not be sufficient by themselves to account for the high prevalence of CVD in patients with this condition. Thus, the search for other, non-traditional, risk factors that may be involved in the pathogenesis of uremic CVD has been an area of intense study. Data suggest that the accelerated atherosclerotic process of ESRD may involve several interrelated processes, such as oxidative stress, endothelial dysfunction and vascular calcification, in a milieu of constant low-grade inflammation. The cause(s) of inflammation in ESRD are multifactorial and, while it may reflect underlying CVD, an acute-phase reaction may also be a direct cause of vascular injury via several pathogenetic mechanisms. Available data suggest that pro-inflammatory cytokines play a central role in the genesis of both malnutrition and CVD in ESRD. Thus, it could be speculated that suppression of the vicious cycle of malnutrition, inflammation and atherosclerosis (MIA syndrome) would improve survival in dialysis patients. Recent evidence has demonstrated strong associations between inflammation and both increased oxidative stress and endothelial dysfunction in ESRD patients. As there is not yet any recognized, or even proposed, treatment for ESRD patients with chronic inflammation it would be of obvious interest to study the long-term effect of various anti-inflammatory treatment strategies on the nutritional and cardiovascular status as well as outcome of these patients.

Prescribe by Risk: The Utility of a Biomarker-Based Risk Calculation in Disease Management to Prevent Heart Disease

Preventive treatment for those most at risk of heart disease rather than those with the highest blood pressure or cholesterol values may be a more efficacious strategy for disease management. This depends on accurate biomarker-based risk assessment tools. An evidence-based model of heart disease risk was developed using the Framingham model with an additional five risk factors, including three of the newer blood biomarkers. This was applied to the adult population of the 3rd National Health and Nutrition Examination Survey cohort. Additionally, the selection criteria for therapeutic intervention from the Adult Treatment Panel III guidelines (for hyperlipidemia) and the 7th Report of the Joint National Committee (for hypertension) were applied to the same subjects. Of this cohort 54% qualified for at least one of these medications while 18% qualified for both. Using this 18% cutoff, the 18% of the subjects with the highest calculated heart disease risk were also identified using the developed risk model. We applied established therapeutic reductions in heart disease probability to those identified by guidelines and to those identified by risk. Applying both drugs to the high-risk group (one third the size of the guidelines group) achieved the same reduction in population risk (about one fourth) as applying the drugs to the guideline groups and required only half as many prescriptions. Intermediate results were found when an intervention group was identified by a combination of both high risk and high levels of risk factors. In this simulation, identifying patients by heart disease risk level resulted in substantially fewer people being treated with fewer drugs and achieving a similar reduction in disease risk.

Strain-dependent beta-adrenergic receptor function influences myocardial responses to isoproterenol stimulation in mice

Recently, we showed that compared with the A/J inbred mouse strain, C57BL/6J (B6) mice have an athlete's cardiac phenotype. We postulated that strain differences would result in greater left ventricular (LV) hypertrophy in response to isoproterenol in B6 than A/J mice and tested the hypothesis that a differential response could be explained partly by differences in beta-adrenergic receptor (beta-AR) density and/or coupling. A/J and B6 mice were randomized to receive daily isoproterenol (100 mg/kg sc) or isovolumic vehicle for 5 days. Animals were studied using echocardiography, tail-cuff blood pressure, histopathology, beta-AR density and percent high-affinity binding, and basal and stimulated adenylyl cyclase activities. One hundred twenty-eight mice (66 A/J and 62 B6) were studied. Isoproterenol-treated A/J mice demonstrated greater percent increases in echocardiographic LV mass/body weight (97 +/- 11 vs. 20 +/- 10%, P = 0.001) and in gravimetric heart mass/body weight versus same-strain controls than B6 mice. Histopathology scores (a composite of myocyte hypertrophy, nuclear changes, fibrosis, and calcification) were greater in isoproterenol-treated A/J vs. B6 mice (2.8 +/- 0.2 vs.1.9 +/- 0.3, P < 0.05), as was quantitation of myocyte damage (22.3 +/- 11.5 vs. 4.3 +/- 3.5%). Interstrain differences in basal beta-AR density, high-affinity binding, and adenylyl cyclase activity were not significant. However, whereas isoproterenol-treated A/J mice showed nonsignificant increases in all beta-AR activity measures, isoproterenol-treated B6 mice had lower beta-AR density (57 +/- 6 vs. 83 +/- 8 fmol/mg, P < 0.05), percent high-affinity binding (15 +/- 2 vs. 26 +/- 3%, P < 0.005), and GTP + isoproterenol-stimulated adenylyl cyclase activity (10 +/- 1.1 vs. 5.8 +/- 1.5 pmol cAMP.mg(-1).min(-1)) compared with controls. High-dose, short-term isoproterenol produces greater macro- and microscopic cardiac hypertrophy and injury in A/J than B6 mice. A/J mice, unlike B6 mice, do not experience beta-AR downregulation or uncoupling in response to isoproterenol. Abnormalities in beta-adrenergic regulation may contribute to strain-related differences in the vulnerability to isoproterenol-induced cardiac changes.

Renal transplant recipients with coronary artery disease exhibit impairment in fibrinolysis and structural changes in carotid arteries

Cardiovascular disease (CVD) is the main cause of mortality and morbidity among kidney transplant recipients (Tx). Intima-media thickness (IMT) of the common carotid artery is related to CVD. Hemostatic disturbances may contribute to the CVD pathogenesis in Tx. The aim of the study was to evaluate some hemostatic factors in Tx with and without coronary artery disease (CAD) and their correlations with IMT. Patients with CAD were significantly older, with thicker IMT, lower plasmin-antiplasmin complexes (PAP), higher fibrinogen, cholesterol, triglycerides, Thrombin-activatable fibrinolysis inhibitor (TAFI) antigen and activity, prolonged euglobulin clot lysis time when compared to those without CAD. Kidney transplant recipients have higher mean blood pressure, serum lipids, fibrinogen, TAFI antigen, TAFI activity, markers of coagulation and fibrinolysis, thicker IMT and lower PAP relative to healthy volunteers. In univariate analysis, IMT correlated significantly with age, time on dialysis prior to transplantation, PAP, fibrinogen, hematocrit, body mass index (BMI). Multiple regression analysis showed that only age, hematocrit, PAP, and time on dialysis prior to transplantation were positive independent predictors of IMT. Hypofibrinolysis may contribute to the arterial remodeling in Tx. Dialysis therapy before transplantation makes detrimental changes in arterial vasculature.

Analysis of the cardiovascular risk profile in stable kidney transplant recipients after 50% cyclosporine reduction

BACKGROUND

Long-term use of cyclosporine (CsA) contributes to post-transplant cardiovascular disease (CVD). Hence, a reduction in CsA dosage in kidney transplant recipients (KTR) may improve long-term outcomes. We analyzed the effects of 50% CsA dose reduction on the CVD risk profile in stable KTR.

METHOD

Thirty-one KTR on a regimen of CsA, prednisone and mycophenolate mofetil (MMF) were studied. Patients were randomized to either a) continue their previously determined CsA dose (control group, n = 15) or b) lower their CsA dose by 50% (CsA reduction group, n = 16). Renal function, blood pressure, lipid profile, plasma homocysteine (HCY), C-reactive protein (CRP), fibrinogen, and uric acid were compared at baseline and at 6 months.

RESULTS

At 6 months, there was a significant improvement in allograft function, systolic blood pressure, number of anti-hypertensive medications and serum uric acid levels in the CsA reduction group. No significant decrease in plasma HCY, CRP, fibrinogen or improvement in lipid profile was found. In contrast, in the Control group, there was a significant increase in HCY, uric acid, and triglycerides. No acute rejection occurred in either group.

CONCLUSIONS

A greater reduction in CsA dose could further improve CVD risk profiles, although this may increase the risk of acute or subclinical rejection.