Flow-mediated vasoactivity and circulating adhesion molecules in hypertriglyceridemia: association with small, dense LDL cholesterol particles

Relationship Between Serum Endocan Levels and Other Predictors of Endothelial Dysfunction in Obese Women

Endocan, or endothelial cell-specific molecule-1 (ESM-1), is a potential inflammatory marker implicated in endothelial dysfunction. The purpose of this study was to determine the correlation between serum endocan levels and the presence and severity of endothelial dysfunction, and the relationships with serum intracellular adhesion molecule-1 (ICAM-1), adiponectin (a marker of inflammation), high sensitivity C-reactive protein (hsCRP) levels, and carotid intima-media thickness (cIMT) in obese subjects. Serum endocan, ICAM-1, adiponectin, hsCRP levels, and cIMT were evaluated in 76 obese women (BMI > 30 kg/m2) and 53 controls (BMI < 25 kg/m2). ICAM-1 (P = .01), hs-CRP (p < 0.001), and cIMT (p < .001) were significantly higher, while adiponectin (P = .006) was significantly lower, in obese women compared with the controls. Serum endocan levels were similar between the obese (470.5 ± 171.3 pg/mL) and controls (471.9 ± 146.3 pg/mL) (P = .732). There was no correlation between serum endocan values and the endothelial dysfunction markers, hsCRP (r = -.021), ICAM-1 (r = -.054), adiponectin (r = .113), or cIMT (r = -.060) in obesity. Endocan is not a suitable marker of endothelial dysfunction in the context of obesity. More research is required to evaluate the role of endocan in the regulation of inflammatory processes in obesity.

Endothelial Function in Dyslipidemia: Roles of LDL-Cholesterol, HDL-Cholesterol and Triglycerides

Dyslipidemia is associated with endothelial dysfunction. Endothelial dysfunction is the initial step for atherosclerosis, resulting in cardiovascular complications. It is clinically important to break the process of endothelial dysfunction to cardiovascular complications in patients with dyslipidemia. Lipid-lowering therapy enables the improvement of endothelial function in patients with dyslipidemia. It is likely that the relationships of components of a lipid profile such as low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides with endothelial function are not simple. In this review, we focus on the roles of components of a lipid profile in endothelial function.

Effects of Exercise on Extracellular Vesicles in Patients with Metabolic Dysfunction: a Systematic Review

The aim of this study was to investigate the effect of exercise on extracellular vesicles (EVs) in patients with metabolic dysfunction. The literatures were searched until Apr 28, 2022, and 16 studies that met inclusion criteria were included in this review. The results showed that the concentrations of platelet-derived extracellular vesicles (PEVs) and endothelial cell-derived extracellular vesicles (EEVs) decreased after long-term exercise, especially for CD62E⁺ EEVs and CD105⁺ EEVs. Simultaneously, exercise improved the concentration of clinical evaluation indicators of metabolic diseases, and the changes in these indicators were positively correlated with the changes of EEVs and PEVs. The concentration of skeletal muscle-derived extracellular vesicles (SkEVs) increased after a single bout of exercise. The aforementioned results indicated that long-term exercise might improve endothelial function and hypercoagulability in patients with metabolic dysfunction. The changes in concentrations of EVs could assist in assessing effect of exercise on patients with metabolic dysfunction.

Advances and Challenges in Biomarkers Use for Coronary Microvascular Dysfunction: From Bench to Clinical Practice

Coronary microvascular dysfunction (CMD) is related to a broad variety of clinical scenarios in which cardiac microvasculature is morphologically and functionally affected, and it is associated with impaired responses to vasoactive stimuli. Although the prevalence of CMD involves about half of all patients with chronic coronary syndromes and more than 20% of those with acute coronary syndrome, the diagnosis of CMD is often missed, leading to the underestimation of its clinical importance. The established and validated techniques for the measurement of coronary microvascular function are invasive and expensive. An ideal method to assess endothelial dysfunction should be accurate, non-invasive, cost-effective and accessible. There are varieties of biomarkers available, potentially involved in microvascular disease, but none have been extensively validated in this heterogeneous clinical population. The investigation of potential biomarkers linked to microvascular dysfunction might improve the assessment of the diagnosis, risk stratification, disease progression and therapy response. This review article offers an update about traditional and novel potential biomarkers linked to CMD.

Hypertriglyceridemia: A Neglected Risk Factor for Ischemic Stroke?

Hypertriglyceridemia is caused by defects in triglyceride metabolism and generally manifests as abnormally high plasma triglyceride levels. Although the role of hypertriglyceridemia may not draw as much attention as that of plasma cholesterol in stroke, plasma triglycerides, especially nonfasting triglycerides, are thought to be correlated with the risk of ischemic stroke. Hypertriglyceridemia may increase the risk of ischemic stroke by promoting atherosclerosis and thrombosis and increasing blood viscosity. Moreover, hypertriglyceridemia may have some protective effects in patients who have already suffered a stroke via unclear mechanisms. Therefore, further studies are needed to elucidate the role of hypertriglyceridemia in the development and prognosis of ischemic stroke.

Association Between Lipids and Arterial Stiffness for Primary Cardiovascular Prevention in a General Middle-Aged European Population

Background

Dyslipidemia contributes to the progression of arterial stiffness (AS). The purpose of this study was to investigate the association of the different lipid parameters with arterial stiffness index (ASI) in a middle-aged population free of cardiovascular (CV) disease.

Methods

Among 71,326 volunteers from the UK Biobank population, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), lipoprotein (a) [Lp(a)], apolipoproteins A and B (Apo A and Apo B), and ASI were measured. Values for non-HDL, TC/HDL, TG/HDL, and LDL/HDL were calculated. AS was defined as an ASI > 10 m/s. Associations between lipid parameters and ASI were performed using multiple linear logistic regressions. The results reported from univariate models were the squared partial correlation coefficient, r ², and from multivariate models, the adjusted coefficient of determination, R ², to describe the contribution of ASI variability for each lipid parameter.

Results

We found that TG/HDL was mainly associated with ASI [β = 0.53 (0.01), r ² = 3.66%, p < 0.001 and adjusted β = 0.21 (0.01), R ² = 13.58%, p < 0.001] and AS [odds ratio (OR) = 1.86 (1.80-1.92), r ² = 1.65%, p < 0.001 and adjusted OR = 1.15 (1.13-1.17), R ² = 8.54%, p < 0.001] rather than the others. TG/HDL remained the only lipid parameter that showed added value in linear multivariate models. TG/HDL remained less associated with AS than age (r ² = 5.55%, p < 0.001), mean blood pressure (BP; r ² = 5.31%, p < 0.001), and gender (r ² = 4.44%, p < 0.001), but more highly associated than body mass index (BMI; r ² = 1.95%, p < 0.001), heart rate (HR; r ² = 0.81%, p < 0.001), fasting glucose (r ² = 0.18%, p < 0.001), tobacco (r ² = 0.05%, p < 0.001), and glomerular filtration rate (GFR; r ² = 0.01%, p < 0.001).

Conclusions

In primary CV prevention, lipids, especially through the TG/HDL ratio, could be more instructive in preventing the increase in AS than other modifiable factors.

The levels of hemoglobin are positively associated with arterial stiffness in community-dwelling Chinese adults

BACKGROUND AND AIMS

Hemoglobin (Hb) concentrations are known to be related to cardiovascular diseases. This study investigated the association between Hb levels and arterial stiffness, as assessed by measurement of the brachial-ankle pulse wave velocity (baPWV).

METHODS AND RESULTS

3576 adults (2139 males and 1437 females) from the general Chinese population who had their physical check-ups in the health examination centers of Jiangmen Central Hospital were enrolled into the study. The anthropometrics and laboratory data as well as the baPWV and Hb levels were subsequently obtained. Age-adjusted partial correlation and multivariable stepwise linear regression analyses were used to evaluate the relationships between Hb and baPWV for men and women separately. In both sexes, Hb levels were positively associated with body mass index, total cholesterol, low-density lipoprotein cholesterol, triglycerides, glutamic-pyruvic transaminase, γ-glutamyltranspeptidase, uric acid and baPWV, but negatively correlated with the estimated glomerular filtration rate. Multivariable linear regression analysis showed that Hb was significantly and independently associated with arterial stiffness in men (β = 0.043, 95% CI 0.010-0.077, p < 0.05) and women (β = 0.035, 95% CI 0.001-0.069, P < 0.05), after adjustment for confounding factors.

CONCLUSION

The data indicate that high Hb concentration significantly correlate with increased baPWV in general Chinese population.

Lower triglyceride levels are associated with better endothelial function

BACKGROUND

Increased serum triglyceride levels are independently associated with endothelial dysfunction. However, there is little evidence to define normal levels of triglycerides and there is little information on endothelial function in subjects with extremely low levels of triglycerides.

OBJECTIVE

The purpose of this study was to determine the relationship between triglycerides, especially low levels of triglycerides, and vascular function.

METHODS

We measured flow-mediated vasodilation (FMD) in 7047 subjects and nitroglycerine-induced vasodilation (NID) in 1017 subjects. We divided the subjects into eight groups by triglyceride levels: <50 mg/dL, 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL.

RESULTS

FMD was significantly higher in subjects with triglyceride levels of <50 mg/dL than in subjects with triglyceride levels of 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL (p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Using triglyceride levels of >200 mg/dL as a reference, the odds ratios for a lower quartile of FMD were significantly lower in the <50 mg/dL group, 50-69 mg/dL group, 70-89 mg/dL group, and 90-109 mg/dL group after adjustment for age, gender and other cardiovascular risk factors. There was a slight negative correlation between NID and triglycerides (r=-0.074; p=0.019). However, there was no significant differences in NID among the eight groups.

CONCLUSIONS

FMD values were highest in subjects with extremely low levels of triglycerides (<50 mg/dL). Lower triglyceride levels were associated with better endothelial function.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012950).

Atherogenic index of plasma is related to arterial stiffness but not to blood pressure in normotensive and never-treated hypertensive subjects

BACKGROUND AND AIMS

Atherogenic index of plasma (AIP), defined as the logarithm of triglycerides to high-density lipoprotein cholesterol (HDL-C) ratio, is a strong predictor of future cardiovascular disease. Our aim was to examine the association of AIP with haemodynamic variables in normotensive and never-treated hypertensive subjects in a cross-sectional study.

METHODS

Supine haemodynamics in 615 subjects without antihypertensive and lipid-lowering medications were examined using whole-body impedance cardiography and radial pulse wave analysis. Linear regression analysis was applied to investigate the association of AIP with haemodynamic variables and age, sex, body mass index (BMI), smoking status, alcohol consumption, plasma C-reactive protein, electrolytes, uric acid, low density lipoprotein cholesterol (LDL-C), estimated glomerular filtration rate, and quantitative insulin sensitivity check index.

RESULTS

The demographics and laboratory values of the study population were (mean ± 95% confidence interval): age 44.9 ± 1.0 years, BMI 26.8 ± 0.4 kg/m², office blood pressure 140.6 ± 1.6/89.4 ± 1.0 mmHg, total cholesterol 5.2 ± 0.08, LDL-C 3.1 ± 0.08, triglycerides 1.2 ± 0.08, HDL-C 1.6 ± 0.04 mmol/l, and AIP -0.15 ± 0.02. Age (standardized coefficient Beta 0.508, p < .001) and aortic systolic blood pressure (Beta 0.239, p < .001) presented with the strongest associations with pulse wave velocity. However, AIP was also associated with pulse wave velocity (Beta 0.145, p < .001). AIP was not related with aortic or radial blood pressure, cardiac output, systemic vascular resistance, or augmentation index.

CONCLUSIONS

AIP is directly and independently associated with arterial stiffness, a variable strongly related to cardiovascular risk. This supports more widespread use of AIP in standard clinical cardiovascular disease risk evaluation.

Combined aerobic and resistance training improves microcirculation in metabolic syndrome

BACKGROUND

Exercise intervention improves macrovascular function in metabolic syndrome (MeS) patients, but few studies have evaluated the effect of exercise on microcirculatory dysfunction, which plays a key role in the development of MeS and its correlated organ damage. We carried out this intervention study to evaluate the influence of an aerobic and resistance training on skin microvascular reactivity in MeS patients.

METHODS

Postocclusive reactive hyperemia (PORH) of the forearm skin was evaluated, by laser-Doppler flowmetry, before and after a 12-week program of aerobic and resistance training in 15 MeS patients referring to our Lipid Metabolism Outpatients Clinic, together with anthropometric, fitness and metabolic parameters; 15 matched MeS patients who did not exercise, served as a control group. The exercise training consisted of 2 sessions/week of aerobic and resistant exercise.

RESULTS

Following exercise program, we observed a significant reduction in body weight, fat mass, fasting blood glucose, serum HbA1c and triglycerides, while HDL-cholesterol significantly increased. The exercise-treated group experienced a significant improvement in the area of hyperemia (AH) after PORH, and in all fitness parameters: VO2max, strength on the pulldown lat machine, chest press, leg press and leg extension. A significant correlation emerged between the increase in AH and the reduction in HbA1c and between increase in AH and strength at the chest press, and at the leg extension.

CONCLUSIONS

Our study showed that a short-term combined aerobic-resistance training positively affects microvascular reactivity in MeS patients. This improvement is correlated with the reduction of HbA1c and fitness parameters, and particularly with increased muscle strength at the upper and lower limbs.

Atherogenic index of plasma is positively associated with the risk of all-cause death in elderly women : A 10-year follow-up

BACKGROUND

The blood concentrations of total cholesterol and low-density lipoprotein (LDL) do not predict survival in patients older than 60 years. The atherogenic index of plasma (AIP) is a logarithm of the triacylglycerol to high-density lipoprotein (HDL) ratio and a surrogate for the concentration of small dense LDL. It might be a better reflection of the risk of all-cause death in elderly patients.

METHODS

We conducted a prospective observational study of patients with arterial hypertension older than 60 years. The concentrations of total cholesterol, LDL, HDL and triacylglycerol were measured at the time of the recruitment and the patients were observed for 10 years. Cox regression analysis was performed to assess the effects of lipoproteins and AIP on survival.

RESULTS

A total of 500 patients were recruited and 473 of them (226 men, 247 women) either died or successfully completed the 10-year follow-up and were included in the analysis. The AIP was positively associated, while HDL concentration was negatively associated with the risk of all-cause death adjusted for age, smoking habits, statin use, history of diabetes mellitus, myocardial infarction, stroke and peripheral artery occlusive disease (PAOD) in elderly women but not in men. The LDL, total cholesterol, triacylglycerol and non-HDL concentrations were not associated with the risk of death in both sexes.

CONCLUSIONS

The AIP is positively associated with the risk of all-cause death in elderly women with arterial hypertension independent of age, smoking habits, statin therapy and comorbidities.

Lipoprotein ratios are better than conventional lipid parameters in predicting arterial stiffness in young men

Although dyslipidemia is associated with cardiovascular disease, there are conflicting data about the role of serum lipids and their ratios in promoting arterial stiffness. The authors aimed to compare serum lipid profiles to predict arterial stiffness, which was assessed by brachial-ankle pulse wave velocity in young Chinese men. A total of 1015 participants aged 18 to 44 years without serious comorbidities were recruited for conventional detection. Anthropometrics, brachial-ankle pulse wave velocity, serum lipids, and other laboratory data were measured. Univariate analysis and multivariate logistic regression were performed to examine the relationship between serum lipid profiles and brachial-ankle pulse wave velocity. Participants with high brachial-ankle pulse wave velocity exhibited higher levels of total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol (HDL-C), total cholesterol/HDL-C, TG/HDL-C, low-density lipoprotein cholesterol/HDL-C, and non-HDL-C/HDL-C. The subsequent multivariable logistic regression showed that TG/HDL-C, total cholesterol/HDL-C, non-HDL-C/HDL-C, and TG significantly increased the risk for arterial stiffness after adjustment for confounding factors. Results indicate that lipid ratios are superior to conventional lipid parameters for predicting arterial stiffness in young men and that the TG/HDL-C ratio has the strongest association with arterial stiffness.

Elevated plasma migration inhibitory factor in hypertension-hyperlipidemia patients correlates with impaired endothelial function

Migration inhibitory factor (MIF) has been shown to be critical in the pathology of early artherosclerosis; this article aim to investigate the plasma levels of MIF in hypertension plus hyperlipidemia patients.A total of 39 hypertension plus hyperlipidemia patients without any previous treatment were enrolled (HTN-HLP). Twenty-five healthy subjects were enrolled as the healthy control group (HEALTHY). Plasma MIF was measured by ELISA; laboratory and clinical characteristics were analyzed. HUVECs were treated with pooled plasma from HTN-HLP and HEALTHY groups, and the protein levels of adhesion molecules VCAM-1 and ICAM-1 were determined by ELISA. We found that plasma MIF was significantly elevated in the HTN-HLP group. Serum NO and eNOS levels were significantly lower; serum ET-1 (endothelin) levels were significantly higher in the HTN-HLP group. Furthermore, blood pressure, baPWV (brachial-ankle pulse wave velocity), and serum ET-1 level were significantly positively; serum NO and eNOS levels were negatively correlated with plasma MIF levels. Plasma from HTN-HLP significantly stimulated VCAM-1 and ICAM-1 protein expression on the surface of HUVECs.Plasma MIF was elevated in HTN-HLP patients and correlates with impaired endothelial function.

Twice weekly intake of farmed Atlantic salmon (Salmo salar) positively influences lipoprotein concentration and particle size in overweight men and women

The US Dietary Guidelines for Americans recommend twice weekly fish intake. Farmed Atlantic salmon is a good source of omega-3 (n-3) fatty acids which have positive lipid modifying effects; however, it is unknown whether these responses are dose-dependent. Our primary research objective was to determine the effect of dose-dependent intake of farmed Atlantic salmon on lipoprotein particle (P) size and concentration. We hypothesized that low-density lipoprotein (LDL)-P and high-density lipoprotein (HDL)-P size and concentration would increase with salmon intake in a dose-dependent manner. Overweight, adult participants (n = 19) were enrolled in a cross-over designed clinical trial evaluating intake of farmed Atlantic salmon. In random order, participants were assigned to 90, 180, or 270 g of salmon twice weekly for 4-week dietary treatments. Following a 4- to 8-week washout, participants crossed over to another dose of fish intake until all treatments were completed. Plasma lipid concentrations were determined and serum lipoprotein concentrations and particle size were determined by nuclear magnetic resonance. Intake of salmon reduced plasma and serum triglyceride (TG) concentrations and increased plasma HDL-C concentrations. The concentrations of large very low-density lipoprotein (VLDL)-P and chylomicron (CM)-P were reduced. Large LDL-P concentrations were increased in a dose-dependent manner. The mean size of VLDL-P was reduced and that of LDL was increased. Total TG was reduced as was the TG content of VLDL-P and CM-P. Twice weekly intake of farmed Atlantic salmon portions influences lipoprotein particle size and concentration in a manner associated with cardiovascular disease risk reduction.

Sucrose non-fermenting AMPK related kinase/Pentraxin 3 and DNA damage axis: a gateway to cardiovascular disease in systemic lupus erythematosus among Egyptian patients

Background

Systemic lupus erythematosus is a chronic multisystemic autoimmune disease characterized by chronic inflammatory processes and failure of immune-regulatory mechanisms. Systemic lupus erythematosus is associated with increased risk for cardiovascular disease. In view of immunometabolic derangements of systemic lupus erythematosus, we investigated the roles of sucrose non-fermenting AMPK related kinase, Pentraxin 3, and DNA damage in the pathogenesis of systemic lupus erythematosus complicated with cardiovascular disease.

Methods

Forty systemic lupus erythematosus women with cardiovascular disease (systemic lupus erythematosus cases), 40 systemic lupus erythematosus women without cardiovascular disease, and 40 healthy controls were enrolled in this study. Demographic and clinical data were recorded. Plasma concentrations of sucrose non-fermenting AMPK related kinase and Pentraxin 3 were immunoassayed. Carotid intima media thickness, atherogenic, and DNA damage indices were also assessed.

Results

Plasma sucrose non-fermenting AMPK related kinase and Pentraxin 3 concentrations were increased in systemic lupus erythematosus cases with cardiovascular disease compared to systemic lupus erythematosus controls and healthy controls ( P < 0.0001). In systemic lupus erythematosus cases, there was a positive correlation between sucrose non-fermenting AMPK related kinase and Pentraxin 3 (r = 0.57, P < 0.002).

Conclusions

These data highlight a novel role of sucrose non-fermenting AMPK related kinase/Pentraxin 3 axis in systemic lupus erythematosus pathogenesis. Sucrose non-fermenting AMPK related kinase/Pentraxin 3 combined role in immunometabolic signaling and DNA damage response is proposed to accelerate cardiovascular complications in systemic lupus erythematosus patients.

Arterial function in cardio-metabolic diseases: from the microcirculation to the large conduits

The metabolic syndrome (MetS) is characterized as a constellation of metabolic risk factors such as obesity, hypertension, dyslipidemia, and hyperglycemia that co-occur within a given individual. This consultation of risk factors exposes MetS to a 3-fold increased risk of cardiovascular disease and an even higher risk of developing type 2 diabetes compared to healthy individuals. The pathophysiological mechanisms underlying this increased cardiovascular risk are incompletely understood but likely include alterations to macro- and micro-vasculature. The vasculature plays an important role not only in delivery and adjusting the quantity of blood delivered to the tissues, but the dynamic changes in structure and compliance significantly alter the hemodynamic stress imposed on the heart and end-organs. This review will give an overview of the pathophysiological changes to the vasculature that accompany MetS in both human and animal models, as well as the possible mechanistic pathways.

Effects of fenofibrate on albuminuria in patients with hypertriglyceridemia and/or hyperuricemia: a multicenter, randomized, double-blind, placebo-controlled, crossover study

BACKGROUND

A slight increase in albuminuria (urinary albumin excretion [UAE] ≥30 mg/d) is associated with hypertension, type 2 diabetes mellitus, dyslipidemia (high triglyceride [TG] and low high-density lipoprotein cholesterol [HDL-C] concentrations), and hyperuricemia. Although antihypertensive and antidiabetic therapies have been reported to reduce UAE, an association between improvement in dyslipidemia and/or hyperuricemia and a reduction in UAE has not been reported.

OBJECTIVE

The aim of this study was to investigate the efficacy and tolerability of fenofibrate on albuminuria in patients with hypertriglyceridemia and/or hyperuricemia.

METHODS

Patients with hypertriglyceridemia and/or hyperuricemia were recruited from general clinics and lipid clinics in Japan; they received fenofibrate (300 mg once daily) in this randomized, double-blind, placebo-controlled, crossover study. Patients in group A received fenofibrate for 8 weeks followed by placebo for an additional 8 weeks, whereas those in group B received placebo for 8 weeks followed by fenofibrate for 8 additional weeks. UAE was measured at baseline and at the end of each 8-week period. Blood tests were performed at baseline and every 4 weeks until study end. Each physician who participated in the study was to record adverse events at each study visit.

RESULTS

A total of 43 patients entered this study (38 men, 5 women; mean [SE] age, 57.1 [1.4] years; mean [SE] body mass index, 24.3 [0.4] kg/m(2)). Twenty-one patients (18 men, 3 women) were randomly assigned to group A and 22 (20 men, 2 women) to group B. In group A, serum TG (P<0.001) and apolipoprotein (apo) C2, C3, and E (all P<0.01) concentrations decreased significantly with fenofibrate, and HDL-C and apo A1 and A2 increased significantly (all P<0.001). All of these parameters returned to near-baseline levels after placebo administration. In group B, serum TG, HDL-C, or apo A1, A2, B, C2, C3, and E concentrations did not change significantly with placebo, but TG (P<0.01), apo C3 (P<0.05), and apo E (P<0.05) were significantly decreased with fenofibrate. In addition, HDL-C (P<0.05), apo A1 (P<0.001), and apo A2 (P<0.01) were significantly increased with fenofibrate. Serum concentrations of TG (group A, P<0.001; group B, P<0.001); apo C2 (group A, P<0.01), C3 (group A, P<0.01; group B, P<0.05), and E (group A, P<0.01; group B, P<0.05); and uric acid (group A, P<0.001; group B, P<0.01) were significantly decreased with fenofibrate compared with placebo. HDL-C and apo A1 and A2 were significantly increased with fenofibrate compared with placebo (all P<0.001 in both groups). Fenofibrate treatment was associated with significant reductions in UAE (group A, P<0.05; group B, P<0.01). Spearman rank correlation analysis showed that changes in UAE were associated with changes in apo C2 (ρ = 0.43; P = 0.02) and apo C3 (ρ = 0.49; P = 0.01) concentrations. Multiple regression analysis revealed that a decrease in apo C3 concentration was independently and significantly associated with reductions in albuminuria (ρ = 0.48; P = 0.01). At the end of the study, neither drug-related nor clinical adverse events were evident in any of the patients, except for an increase in serum creatinine concentration above the upper limit of normal (1.40 mg/dL) in 3 patients (14.3%) in group A and 1 patient (4.5%) in group B.

CONCLUSIONS

In our study population of patients with hypertriglyceridemia and/or hyperuricemia, fenofibrate-induced ameliorations of impaired TG-rich lipoprotein metabolism were associated with reductions in albuminuria.

A randomized cross-over study of inhalation of diesel exhaust, hematological indices, and endothelial markers in humans

BACKGROUND

Exposure to traffic-related air pollution (TRAP) is considered a trigger for acute cardiovascular events. Diesel Exhaust (DE) is a major contributor to TRAP in the world. We evaluated the effect of DE inhalation on circulating blood cell populations, hematological indices, and systemic inflammatory cytokines in humans using a specialized facility.

METHODS

In a randomized double-blind crossover study balanced to order, 17 metabolic syndrome (MetS) and 15 healthy subjects inhaled filtered air (FA) or DE exposure in two-hour sessions on different days with a minimum 2-week washout period. We collected blood pre-exposure, 7, and 22 hours after exposure initiation and measured the complete blood count and differential. We performed multiplex cytokine assay to measure the changes in the systemic inflammatory cytokines, and endothelial adhesion molecules (n=15). A paired analysis compared the effect of DE and FA exposures for the change from pre-exposure to the subsequent time points.

RESULTS

A significant increase in the hematocrit was noted 7 hrs after DE [1.4% (95% CI: 0.9 to 1.9%)] compared to FA exposure [0.5% (95% CI: -0.09 to 1.0%); p=0.008. The hemoglobin levels increased non-significantly at 7 hrs post DE [0.3 gm/dL (95% CI: 0.2 to 0.5 gm/dL)] versus FA exposure [0.2 gm/dL (95% CI: 0 to 0.3 gm/dL)]; p=0.06. Furthermore, the platelet count increased 22 hrs after DE exposure in healthy, but not in MetS subjects [DE: 16.6 (95% CI: 10.2 to 23) thousand platelets/mL versus [FA: 3.4 (95% CI: -9.5 to 16.3) thousand platelets/mL)]; p=0.04. No DE effect was observed for WBC, neutrophils, lymphocytes or erythrocytes. Using the multiplex assay, small borderline significant increases in matrix metalloproteinase-9, interleukins (IL)-1 beta, 6 and 10 occurred 7 hrs post exposure initiation, whereas E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule -1, and myeloperoxidase 22 hrs post exposure.

CONCLUSIONS

Our results suggest that short-term DE exposure results in hemoconcentration and thrombocytosis, which are important determinants of acute cardiovascular events. Multiplex assay showed a non-significant increase in IL-1β and IL-6 immediately post exposure followed by myeloperoxidase and endothelial activation molecules. Further specific assays in a larger population will improve our understanding of the systemic inflammatory mechanisms following acute exposure to TRAP.

Anthracycline causes impaired vascular endothelial function and aortic stiffness in long term survivors of childhood cancer

Vascular and endothelial functions were investigated in long term survivors of childhood cancer exposed to anthracycline treatment. We enrolled 96 long-term survivors (57 males and 39 females, mean age 14.9 ± 5.3 year) of different childhood cancers and 72 age-, sex-, bodyweight- and blood pressure matched controls (39 males and 33 females, mean age 13.7 ± 4.9 year). Aortic stiffness was characterized by echocardiography. Brachial artery endothelial function was assessed by flow-mediated dilatation (FMD%) and nitrate-mediated dilatation (NTG%). Results were compared between three subgroups: anthracycline treated, only chemotherapy treated and control subgroups. The cumulative anthracycline dose was less than 350 mg/m². The healthy control subgroup had a significantly greater FMD response (13.13 ± 2.40 %), and lower stiffness index (2.08 ± 0.6) than both the anthracycline (7.12 ± 6.28 % and 6.45 ± 3.25, respectively) and only chemotherapy treated (10.17 ± 4.23 % and 4.12 ± 2.32, respectively) subgroups. In the anthracycline treated subgroup a significantly (p < 0.01) lower FMD% response, and higher stiffness index were detected than in the only chemotherapy treated subgroup. Higher triglyceride level, higher cumulative anthracycline dose and lower age at the start of treatment were found to be associated independently with impairment of FMD% response and aortic stiffness. We found a significant negative correlation between FMD and aortic stiffness (p < 0.001) and a positive correlation between FMD and distensibility (p < 0.0001). Childhood cancer long term survivors exposed to anthracycline treatment exhibit a marked preclinical vasculopathy, characterized by endothelial dysfunction and increased arterial stiffness, contributing to a deteriorated cardiovascular function.

Time-dependent changes of erectile function in diabetic rats: role of systemic endothelial dysfunction

PURPOSE

To understand the potential contribution of systemic endothelial dysfunction to diabetic erectile dysfunction, and the time course of erectile dysfunction in a streptozotocin (STZ)-induced diabetic rat model.

MATERIALS AND METHODS

Among 84, 12-week-old Sprague-Dawley rats, 48 rats received intraperitoneal STZ and were classified into six groups of diabetes by the period of observation (n=8). The remaining 36 rats were also grouped, similar to the diabetic groups, and served as normal controls. After 4, 6, 8, 10, 12, and 14 weeks of diabetes (serum glucose >250 mg%), all rats underwent cavernous nerve electrostimulation (3 V, 0.2 ms, 30 sec) with varying frequency (2.5~20 Hz). At the end of the study, 8 ml of blood was taken to measure the plasma markers of endothelial function and glycosylated hemoglobin.

RESULTS

Compared to the control, significant reduction of erectile response was not observed until eight weeks after diabetes induction. The diabetic rats had elevation of all plasma markers except for l-selectin. However, the correlation analysis revealed that no systemic marker of endothelial dysfunction was associated with change in erectile function. Only the level of hemoglobin A1c (HbA1c) showed a modest but significant correlation with the peak intracavernosal pressure, corrected by mean arterial pressure (ρ=-0.183), and the area under the curve of the cavernosometry (ρ=-0.207).

CONCLUSIONS

Significant reduction of erectile function was not observed until eight weeks after the induction of diabetes. Except for HbA1c, there was no systemic marker associated with endothelial activation and erectile function in the diabetic rats.

Metabolic syndrome and its components associated with endothelial dysfunction in chronic kidney disease patients

BACKGROUND

Cardiovascular disease is more common in patients with chronic kidney disease (CKD) than in the general population. Endothelial dysfunction is an early predictor of cardiovascular events.

OBJECTIVE

We conducted a cross-sectional study in CKD patients to explore the association of metabolic syndrome (MetS) components with endothelial cell function.

METHODS

We evaluated clinical and laboratory data in 161 CKD patients from stage 1 to stage 5. Endothelial function was estimated by flow-mediated dilatation (FMD) of the brachial artery and expressed as percentage change relative to baseline diameter. MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III criteria.

RESULTS

Patients were grouped into two groups according to whether or not they had MetS. FMD was significantly lower in the MetS group than in the group without MetS (P = 0.012). In a Pearson's correlation analysis, FMD was significantly negatively correlated with waist circumference in women (r = -0.223, P = 0.03) and fasting blood glucose (r = -0.186, P = 0.001). Multiple linear regression analysis showed that fasting blood glucose was an independently associated factor for FMD.

CONCLUSION

MetS and some components of MetS (waist circumference in women and fasting blood glucose) are closely associated with a decreased FMD in CKD patients.

Dietary, lifestyle and pharmacogenetic factors associated with arteriole endothelial-dependent vasodilatation in schizophrenia patients treated with atypical antipsychotics (AAPs)

PURPOSE

Within schizophrenia cardiovascular disease (CVD) is highly prevalent secondary to atypical antipsychotic (AAP) use. Thorough assessments of diet, lifestyle, and endothelial functioning have not been done in this population. Omega 3 Fatty Acids (N-3 FAs) have garnered attention in relation to psychopathology as well as cardioprotection. This study examined the status of endothelial function within the schizophrenia population and determined pharmacogenetic, medication, dietary, and lifestyle factors associated with this functioning.

METHODS

Schizophrenia subjects were screened for the metabolic syndrome along with physical activity, smoking, and variants related to folate pharmacogenetics in this cross-sectional analysis. Arteriole endothelial-dependent vasodilatation was measured using non-invasive peripheral arterial tonometry (RH-PAT, EndoPAT2000). A 24h dietary food recall was used to construct intake profiles using the Nutrition Data Systems for Research software (NDSR). We examined associations between AAP use and RH-PAT values, and the influence of N-3 FA dietary intake on this measure. Preliminary data are reported in 83 subjects with a mean age (±s.d.) of 45.89 (±11.49), 64% were Caucasian (n=53), 64% were male (n=53), and 77% were receiving AAP treatment (n=63).

RESULTS

A significant positive relationship was found between RH-PAT values and N-3 FA intake (F=17.7(1,16), p=0.0007) in subjects not receiving AAPs. This relationship was lost in those treated with AAPs (F=0.25(1,43), p>0.6). Regression analysis confirmed the interaction effect of AAP treatment on the relationship between RH-PAT and N-3 FAs (p=0.0105). Endothelial dysfunction was also related to folate pharmacogenetic variants.

CONCLUSIONS

AAPs may counteract some vascular health benefits of a diet high in N-3 FAs. AAP use may necessitate a higher N-3 FA dose to regain these effects, but additional research is necessary to strengthen the preliminary findings. Pharmacogenetic variants related to folate and homocysteine metabolism may also increase endothelial dysfunction risk.

Examination of adhesion molecules, homocysteine and hs-CRP in patients with polygenic hypercholesterolemia and isolated hypertriglyceridemia

BACKGROUND

Increased levels of selectins, adhesion molecules, hs-CRP and homocysteine are considered important as indicators of atherosclerosis. There is a significant amount of evidence that high LDL-C levels are a risk factor for coronary artery disease, whereas the relevance of isolated triglycerides is controversial. The present study aims to compare the levels of homocysteine, hs-CRP, E-selectin, sP-selectin, VCAM-1, ICAM-1 in patients with isolated hypertriglyceridemia and polygenic hypercholesterolemia.

METHODS

The following three groups were formed: polygenic hypercholesterolemia group (n=30), isolated hypertriglyceridemia group (n=30) and control group (n=30). These three groups were matched in terms of BMI, waist circumference and gender. Plasma high sensitive CRP, homocysteine, sVCAM-1, sICAM-1, sP-selectin, sE-Selectin levels of patients in these three groups were measured.

RESULTS

In the present study, mean values for sE-selectin, sVCAM-1 and sICAM-1 in the polygenic hypercholesterolemia group were significantly higher than in the other two groups (p<0.001). Homocysteine and hs-CRP levels were higher in the polygenic hypercholesterolemia group, compared to the isolated hypertriglyceridemia group (p=0.019, p<0.001; respectively) and the control group (p<0.001, p<0.001; respectively). Comparison of patients with hypertriglyceridemia to individuals in the control group did not yield a significant difference in terms of sE-selectin, sP-selectin, sVCAM-1, sICAM and homocysteine (p>0.05), where as the hs-CRP value was significantly higher in patients with isolated hypertriglyceridemia compared to the control group (p=0.001).

CONCLUSION

The increase of adhesion molecules, homocysteine and hs-CRP in polygenic hypercholesterolemia subjects compared to the isolated hypertriglyceridemia group reflects their high cardiovascular risk.

Assessment of atherosclerosis: the role of flow-mediated dilatation

Evidence suggests that endothelial dysfunction is on the causal pathway for both atherogenesis and destabilization of established plaques. In this review, the role of flow-mediated dilatation (FMD) as a non-invasive method to assess endothelial function is discussed. Technical modifications and development of analysis software have significantly improved the variability of the method. Following a strict standardized protocol enables reproducible measurements to be achieved and export of the technique from specialized laboratories to population studies and multicentre settings. Endothelial function assessed by FMD has been shown to be affected by cardiovascular risk factors, to be related to structural arterial disease and to cardiovascular outcome, validating its use for studying the pathophysiology of arterial disease. Numerous studies have also demonstrated that it is responsive to physiological and pharmacological interventions. Flow-mediated dilatation provides unique opportunities in drug development programmes to assess an early rapidly responsive signal of risk or benefit, complementing endpoints of structural arterial disease and cardiovascular outcomes that take much longer and are more expensive.

Asymmetric dimethylarginine as a mediator of vascular dysfunction and a marker of cardiovascular disease and mortality: an intriguing interaction with diabetes mellitus

Asymmetric dimethylarginine (ADMA) has evolved as an important regulator of nitric oxide (NO) synthesis in recent years. Elevated levels of ADMA have been reported in many conditions associated with a high cardiovascular risk. Moreover, ADMA is a biomarker for major cardiovascular events and mortality in cohorts with high, intermediate and low overall cardiovascular risk. Discrepant data have been reported on cardiovascular risk in people with and without diabetes mellitus, and the association of ADMA with diabetes mellitus per se has also remained controversial, possibly relating to type and stage of diabetes. Clinical and experimental data suggest that there is a multifaceted link between ADMA and insulin metabolism and action on one hand, and ADMA and glucose utilisation on the other. This interplay may be regulated by the enzyme involved in the metabolic degradation of ADMA, dimethylarginine dimethylaminohydrolase (DDAH). Recent data from prospective clinical studies suggest that whilst ADMA may be a marker for total mortality in patients without diabetes, elevated ADMA may exert beneficial effects in patients with diabetes. In this respect, ADMA could serve as a re-coupling agent overcoming endothelial nitric oxide synthase (eNOS) uncoupling in patients with diabetes. Anticipated advances in clinical and experimental investigation will help us to better understand this complex interrelationship between diabetes, eNOS, DDAH and ADMA.

Endothelial dysfunction in metabolic syndrome: prevalence, pathogenesis and management

The metabolic syndrome (MetS) is characterized by the presence of central obesity, impaired glucose metabolism, dyslipidemia and hypertension. Several studies showed that MetS is associated with increased risk for type 2 diabetes mellitus (T2DM) and vascular events. All components of MetS have adverse effects on the endothelium. Endothelial dysfunction plays a role in the pathogenesis of atherosclerosis and might also increase the risk for insulin resistance and T2DM. We review the prevalence and pathogenesis of endothelial dysfunction in MetS. We also discuss the potential effects of lifestyle measures and pharmacological interventions on endothelial function in these patients. It remains to be established whether improving endothelial function in MetS will reduce the risk for T2DM and vascular events.

Glucose intolerance and decreased early insulin response in mice with severe hypertriglyceridemia

Hypertriglyceridemia (HTG) is one of the key features of dyslipidemia in type 2 diabetes, caused by the overproduction and/or decreased clearance of triglyceride (TG)-rich lipoproteins, and significantly promotes the development of cardiovascular diseases in diabetes. However, the effect of severe HTG on glucose metabolism has not previously been determined. Lipoprotein lipase (LPL) deficiency results in severe HTG in humans. By using LPL-deficient mice with severe HTG, we assessed the impact of severe HTG on insulin secretion and glucose tolerance in the present study. While young LPL-deficient mice (4 months of age) showed higher fasting blood glucose (7.42 ± 0.84 versus 4.8 ± 0.80 mmol/L, P < 0.01) and lower insulin concentrations (0.16 ± 0.03 versus 0.48 ± 0.14 ng/mL, P < 0.05), old mice (12 months of age) had higher insulin (1.70 ± 0.35 versus 0.77 ± 0.04 ng/mL, P < 0.05) but normal fasting blood glucose concentrations. Both young and old mice had elevated free fatty acid (FFA) concentrations and exhibited decreased early insulin response; however, only old mice showed impaired glucose tolerance, as compared with wild-type mice of a similar age. Morphological assessment showed enlarged islets in old LPL-deficient mice. These findings suggest that different tests for glucose homeostasis may be needed for patients with LPL deficiency and severe HTG, even though their glucose concentrations are normal at initial screening.

The Effect of Ciprofibrate on Flow-Mediated Dilation and Inflammatory Markers in Patients with Combined Hyperlipidemia

Impairment of flow-mediated dilation (FMD) has been shown to be associated with hypercholesterolemia and hypertriglyceridemia and reduction of cholesterol and/or triglyceride levels can improve FMD. In hyperlipidemia the role of inflammatory substances on endothelial function requires further clarification. In patients with combined hyperlipidemia (n = 29), the capacity of FMD was weaker whereas the levels of interleukin (IL)-lalpha, tumor necrosis factor alpha (TNFalpha), soluble intercellular adhesion molecule (sICAM), and fibrinogen were higher compared to normolipemic controls with normal FMD adjusted for age and sex. Patients were randomized to a diet-only or to a ciprofibrate treatment group. After 8 weeks FMD levels rose significantly both in the diet-only (10.2%) and the ciprofibrate treatment (79.4%) groups. In the diet-only group improvement of FMD was significantly associated with the reduction of triglyceride (by 15.9%) and cholesterol (6.9%) levels. The much larger improvement of FMD due to ciprofibrate therapy was accompanied by significant reductions of cholesterol (by 14.4%), fibrinogen, IL-1alpha, and sICAM levels and by significant increase of high-density lipoprotein (HDL) cholesterol concentration, but the change in FMD correlated only with the reduction of the cholesterol level. In line with previous data the authors emphasize that improvement of FMD in patients with combined hyperlipidemia treated with diet and/or ciprofibrate is linked directly to the reduction of cholesterol and triglyceride concentrations rather than to changes in the level of the investigated inflammatory markers.

Endothelial activation, inflammation and premature atherosclerosis in children with familial dyslipidemia

OBJECTIVES

Prospective studies demonstrated an increased cardiovascular risk in subjects with high levels of either the endothelial-platelet activation marker P-selectin or high-sensitivity C-reactive protein (hs-CRP). Both children with heterozygous familial hypercholesterolemia (FH) and those with familial combined hyperlipidemia (FCHL) are prone to premature atherosclerosis. Our objective was to investigate in children with either FH or FCHL whether P-selectin and hs-CRP contribute to carotid intima-media thickness (IMT), along with increased plasma lipid levels.

METHODS

Carotid IMT, serum lipids and soluble P-selectin and hs-CRP levels were measured in 88 children (mean age 10.5+/-4.3 years) including 44 dyslipidemic children (25 with FH and 19 with FCHL) and 44 non-dyslipidemic controls.

RESULTS

Carotid IMT was significantly higher among dyslipidemic than in control children (0.46+/-0.06mm vs 0.43+/-0.06mm, p=0.003) and serum P-selectin levels as well [129(50-254)ng/mL vs 50(24.5-130)ng/mL, p<0.001]. FH but not FCHL children had higher hs-CRP levels than controls [0.7(0.01-6.9)mg/L vs 0.3(0.1-1.2)mg/L, p=0.006]. In the entire sample of dyslipidemic children, carotid IMT was positively associated with soluble P-selectin levels (rho=0.30, p=0.049), but not with hs-CRP. The association between P-selectin and carotid IMT was independent from confounders, including plasma lipid levels.

CONCLUSION

Endothelial-platelet activation, more than low-grade systemic inflammation, correlates with premature atherosclerosis among children with familial dyslipidemia, this association being independent from plasma lipid levels.

Flow-mediated vasodilatation: variation and interrelationships with plasma lipids and lipoproteins

OBJECTIVE

Endothelial dysfunction is a critical, prerequisite step in atherosclerosis, and may be evaluated by flow-mediated vasodilatation (FMD). The objective of this study was to examine interrelationships between FMD and plasma lipids and lipoproteins, and to determine the between-operator and within-subject variability associated with this technique.

MATERIAL AND METHODS

FMD, plasma lipids and lipoproteins, including small dense LDL (sdLDL), were measured twice in 40 healthy volunteers, 4 weeks apart. Interrelationships between mean FMD responses and plasma lipids and lipoproteins were examined by correlation analysis. FMD measurements were taken by two independent operators, allowing determination of between-operator variability. Within-subject variability was determined by obtaining two measurements, 4 weeks apart, in every subject, and carried out by the same operator.

RESULTS

FMD was inversely related to plasma triglycerides (r = -0.47, p = 0.002), total cholesterol/HDL cholesterol (r = -0.35, p = 0.03) and apolipoprotein B (r = -0.36, p = 0.02), but not to other plasma lipids and lipoproteins. When measuring variation in FMD, the following results were found: Between operators (SD = 4.0 FMD%) and within subjects (SD = 2.9 FMD%).

CONCLUSIONS

The associations between FMD, plasma triglycerides and apoB provide evidence supporting a role for triglyceride-rich lipoproteins in endothelial dysfunction.

Influence of n-3 polyunsaturated fatty acids on soluble cellular adhesion molecules as biomarkers of cardiovascular risk in young healthy subjects

BACKGROUND AND AIM

Serum levels of soluble cellular adhesion molecules (CAMs) and blood lipid parameters have been used as markers of inflammatory processes associated with cardiovascular disease (CVD) events. The present study evaluated the effects of the intake of n-3 polyunsaturated fatty acids (PUFAs) in fish and fish oil within energy-restricted diets, on soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular adhesion molecule-1 (sVCAM-1).

METHODS AND RESULTS

Two hundred and seventy-five healthy European subjects aged between 20 and 40 years, were randomized to one of four hypocaloric dietary groups: control (sunflower oil capsules, no seafood), lean fish (3 x 150 g portions of cod/week), fatty fish (3 x 150 g portions of salmon/week), fish oil ((docosahexaenoic acid (DHA)+eicosapentaenoic acid (EPA) capsules, no seafood)). Diets rich in lean fish significantly decreased ICAM-1 levels, around 5% from baseline to endpoint (p<0.05), and had no effect on VCAM-1 levels. No significant differences were observed in sICAM-1 levels after the intervention with fatty fish or fish oils. On the other hand, these two seafood based diets were responsible for a significant increase of VCAM-1 levels [fatty fish; 16.1% and fish oil; 21.9%] respectively (p<0.05).

CONCLUSIONS

CAMs as inflammatory biomarkers in young and healthy subjects are not conclusive for the evaluation of CVD risk. Hypocaloric fish diets had a different effect on CAMs, being lean fish responsible for the highest decrease in ICAM-1. On the other hand, VCAM-1 results allow speculation that a low dose of n-3 PUFA may be anti-inflammatory contrarily to a high dose which can have a pro-inflammatory effect. CAMs mechanism is complex and affected by multiple factors such as lifestyle, gender, and n-3 dose and source.

A meal rich in oleic acid beneficially modulates postprandial sICAM-1 and sVCAM-1 in normotensive and hypertensive hypertriglyceridemic subjects

This study investigated whether subjects with permanent activated endothelium have altered soluble forms of intercellular adhesion molecule 1 (sICAM-1) and vascular cell adhesion molecule 1 (sVCAM-1) postprandial response to a high-fat meal and whether this phenomenon is modulated by the nature of dietary fats. Twenty-eight hypertriglyceridemic (14 normotensives and 14 hypertensives) and 14 healthy male subjects were placed in a randomized and crossover design on diets enriched in refined olive oil (ROO) or high-palmitic sunflower oil (HPSO) for a 1-week lead-in period. Thereafter, subjects ate the corresponding fat-rich meal as a breakfast and underwent sampling hourly for 8 h. Plasma triglycerides (TG), sICAM-1 and sVCAM-1 were assayed. sICAM-1 and sVCAM-1 postprandial peak levels were significantly higher and occurred later in hypertriglyceridemic subjects (all P<.001) compared with healthy subjects. ROO meal resulted in smaller areas under the curve for sICAM-1 and sVCAM-1 in hypertriglyceridemic (normotensive and hypertensive) and healthy subjects compared to HPSO meal. Hypertension did not aggravate the postprandial response of TG, sICAM-1 and sVCAM-1. We conclude that the challenge of a meal with ROO appears to have a significant postprandial benefit on sICAM-1 and sVCAM-1 as surrogate markers of endothelial activation and vascular inflammation in healthy and more importantly in hypertriglyceridemic (normotensive and hypertensive) subjects.

Effects of weight loss from a very-low-carbohydrate diet on endothelial function and markers of cardiovascular disease risk in subjects with abdominal obesity

BACKGROUND

The effects of a very-low-carbohydrate, high-saturated-fat weight-loss diet (LC) on brachial artery flow-mediated dilatation (FMD) and markers of endothelial function are unknown.

OBJECTIVE

The effect of an LC on markers of endothelial function and cardiovascular disease (CVD) risk was compared with that of an isocaloric high-carbohydrate, low-saturated-fat diet (HC).

DESIGN

FMD and markers of endothelial function (n = 70) and CVD risk were measured before and after 8 wk of weight loss. Ninety-nine subjects aged 50.0 +/- 8.3 y with a body mass index (in kg/m2) of 33.7 +/- 4.1 completed the study.

RESULTS

Mean (+/-SD) FMD did not change significantly (P = 0.55) with either diet. Pulse wave velocity improved with both diets (P < 0.01). Endothelial markers, E- and P selectin, intracellular and cellular-adhesion molecule-1, tissue-type plasminogen activator, and plasminogen activator inhibitor-1 decreased (P < 0.001), with no diet effect. Adiponectin did not change significantly. More weight (P = 0.05 for diet x time interaction) and more abdominal fat mass (P = 0.05 for diet x time interaction) were lost with the LC than with the HC. LDL cholesterol decreased more with the HC than with the LC (P < 0.05, time x diet), and C-reactive protein decreased more with the HC than with the LC (P < 0.05 for diet x time interaction). Homocysteine increased more with the LC (P < 0.01 for diet x time interaction). Folate decreased with the LC and increased with the HC (P < 0.05, time; P < 0.001 for diet x time interaction).

CONCLUSION

An LC does not impair FMD. We observed beneficial effects of both diets on most of the CVD risk factors measured. This trial was registered with the Australian Clinical Trials Registry as ACTR N0 12606000203550.

Insulin resistance is the major determinant for microalbuminuria in severe hypertriglyceridemia: implication for high-risk stratification

OBJECTIVE

The significance of high triglyceride levels as a risk factor for coronary heart disease is uncertain. We hypothesized that oral glucose tolerance test (OGTT) and certain novel markers may help to identify high-risk patients.

PATIENTS AND METHODS

We recruited 80 subjects with severe hypertriglyceridemia (age 27-73 years) without clinical proteinuria and diabetes mellitus (DM) which were diagnosed by fasting glucose <126 mg/dL from Hyperlipidemia Clinic of National Taiwan University Hospital for this study. We applied OGTT to evaluate occult DM and homeostasis model assessment (HOMA)-insulin resistance (IR) score to evaluate insulin resistance, and the measurements of microalbuminuria as a marker of vascular damage. In addition, serum or plasma markers of inflammation and fibrinolysis, fasting glucose and insulin as well as traditional cardiovascular risk factors were also evaluated.

RESULTS

The serum level of triglyceride was higher in patients with microalbuminuria than in those without (14.1+/-5.7 vs. 9.6+/-3.9 mmol/L, p=0.025). Patients with microalbuminuria had higher fasting blood glucose and insulin, higher post-OGTT glucose and insulin, higher prevalence of newly developed diabetes mellitus (DM) (39% vs. 11%, p=0.007) and higher HOMA-IR (6.2+/-4.4 vs. 3.3+/-2.0, p<0.001). Among all the inflammatory and fibrinolytic markers, only soluble intercellular adhesion molecule showed significant different between these two groups. Multiple logistic regression analysis showed that among the serum markers, only HOMA-IR level was significantly related to microalbuminuria.

CONCLUSIONS

HOMA-IR is the major determinant for microalbuminuria in patients with severe hypertriglyceridemia. Impaired glucose metabolism is evident in patients with both severe hypertriglyceridemia and microalbuminuria.

Endothelial function in young adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Adult survivors of childhood acute lymphoblastic leukemia (ALL) have an earlier than expected mortality from cardiovascular disease. This study examined endothelial function in 75 young (age 30.2+/-7.1 y) adult survivors of childhood ALL who received chemotherapy without cranial radiation (n=25) or chemotherapy combined with cranial radiation (n=50) compared with a healthy control group of similar sex, age, and weight (n=59).

PROCEDURE

As part of a clinical follow-up study, endothelial-dependent flow-mediated dilation (FMD: % change in artery diameter after 5 min of occlusion) was assessed using high-resolution ultrasound of the brachial artery. Fifteen minutes after the measurement of FMD, sublingual nitroglycerin (0.4 mg) was administered and the brachial artery was imaged using ultrasound to assess endothelial-independent dilation (EID). All ultrasound imaging data were adjusted for baseline diameter.

RESULTS

The healthy comparison group had a significantly greater FMD response (9.5%+/-2.9%) than both the chemotherapy only (6.5%+/-2.6%) and chemotherapy combined with radiation (7.1%+/-2.6%) groups. No statistical differences were observed in nitrate-mediated EID between the healthy comparison group (27.0%+/-5.0%) and the chemotherapy only (24.7%+/-6.7%) or chemotherapy combined with radiation (25.2%+/-7.1%) groups. Among the ALL survivors, female subjects had a significantly greater FMD and nitrate-mediated EID than male subjects even after correcting for baseline brachial artery diameter.

CONCLUSIONS

These data suggest that young adults treated for ALL during childhood are at risk for impaired FMD regardless of whether or not they received cranial irradiation. The extent to which this mechanism relates to early development of cardiovascular disease in long-term childhood ALL survivors remains to be determined.

Post-prandial endothelial dysfunction in hypertriglyceridemic subjects: Molecular mechanisms and gene expression studies

OBJECTIVE

Triglyceride-rich lipoproteins (TGRLs) are a cardiovascular risk factor and induce endothelial dysfunction. In the present study, we investigated the effects of post-prandial TGRLs from type IV hyperlipidemic subjects on endothelial activation addressing the effects of the lipoproteins on intracellular pathways and gene expression.

METHODS

Thirty fasted hypertriglyceridemic patients were given an oral fat load (OFL) and blood samples were collected before the OFL (T0) and 2, 4, 6 and 8h thereafter. Endothelial function, determined as flow-mediated dilatation of the brachial artery, was assessed at the same time points. TGRLs were isolated at T0 and T4 (PP-TGRL) for in vitro studies.

RESULTS

Compared with TGRLs, PP-TGRLs induced to a larger extent phosphorylation of p38 MAPK, CREB and IKB-alpha in human endothelial cells and increased the DNA binding activity of CREB, NFAT and NF-kappaB. Furthermore, PP-TRGLs upregulated the expression of several pro-inflammatory genes including vascular cell adhesion molecule-1 (VCAM-1), PECAM-1, ELAM-1, intercellular adhesion molecule-1 (ICAM-1), P-selectin, MCP-1, interleukin-6 (IL-6), TLR-4, CD40, ADAMTS1 and PAI-1.

CONCLUSION

These effects may relate to the severe impairment of endothelial function seen during the post-prandial phase in hypertriglyceridemic patients.

Endothelial and leukocyte adhesion molecules in primary hypertriglyceridemia

Hypertriglyceridemia is known to be associated to functional impairment of the endothelium and, consequently, to higher risk of atherosclerosis. Nevertheless, some crucial steps in the development of the atherosclerotic plaque are still unknown in primary hypertriglyceridemia. The aim of the present study was to explore the expression of soluble and leukocyte-associated cell adhesion molecules in a group of patients with primary hypertriglyceridemia, both including (n=50) and excluding (n=24) subjects with metabolic syndrome, in comparison with control normotriglyceridemic individuals (n=30). Lipid profile, CETP activity, HDL and VLDL chemical composition were evaluated. Soluble (VCAM-1, ICAM-1 and E-selectin) and leukocyte cell adhesion molecules (CD18, CD49d and CD54) were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Patients with primary hypertriglyceridemia as compared with control subjects showed significantly higher VCAM-1 (15.6+/-4.5 ng/ml versus 13.9+/-3.8 ng/ml, respectively; p<0.05) and ICAM-1 (16.9+/-3.1 ng/ml versus 15.2+/-3.2 ng/ml, respectively; p<0.05). Regarding leukocyte cell adhesion molecules, significant increases were also detected in monocyte CD18 (398+/-180 versus 332+/-136 arbitrary units, respectively; p<0.05) and CD54 (49+/-14 versus 42+/-12 arbitrary units, respectively; p<0.05), and lymphocyte CD18 (122+/-53 versus 101+/-33 arbitrary units, respectively; p<0.05). ICAM-1 plasma levels, as well as monocyte CD18 and CD54, and lymphocyte CD18 persisted elevated even if patients with metabolic syndrome were discarded among those with hypertriglyceridemia. The increase in circulating and leukocyte cell adhesion molecules in primary hypertriglyceridemic patients would highlight the inflammatory process which is a key event in atherogenesis.

Triglyceride level is associated with wave reflections and arterial stiffness in apparently healthy middle-aged men

OBJECTIVE

To investigate the relationship of arterial stiffness and wave reflections, which are predictors of cardiovascular risk, with serum triglyceride level in healthy adults.

DESIGN

Cross-sectional study at the University Department of Cardiology. 213 healthy individuals (141 men and 72 premenopausal women) not taking any medication and without known cardiovascular disease and risk factors, except for smoking.

MAIN OUTCOME MEASURES

Central (aortic) augmentation index (AIx, a composite measure of arterial stiffness and wave reflections), fasting lipid profile (including triglycerides) and 10-year Framingham Risk Score (FRS).

RESULTS

Compared with women, men had higher serum triglyceride level (median (interquartile range) (89 (67-117) vs 73 (54-96) mg/dl, p<0.01) and lower AIx (17.7 (1.0) vs 26.3 (1.4), p<0.001). In both genders, serum triglyceride levels were significantly associated with FRS (men: r = 0.43, p<0.001; women: r = 0.37, p<0.01) and AIx (men: r = 0.21, p<0.05; women: r = 0.26, p<0.05). In men, multivariate linear regression analysis showed an association between triglyceride level and AIx (standardised beta coefficient = 0.19, p = 0.009), independent of age, blood pressure, heart rate, height, weight, smoking habits, total cholesterol and HDL-cholesterol levels. On the other hand, in women, the unadjusted correlation between triglyceride level and AIx was largely explained when the above mentioned confounders were taken into account (beta = -0.016, p = 0.86).

CONCLUSION

In healthy men, serum triglyceride levels are associated with indices of arterial stiffness and wave reflections, which are important determinants of cardiovascular function and risk. The role of triglycerides in the vascular function of women warrants further investigation.

Association of endothelial function and vascular data with LDL-c and HDL-c in a homogeneous population of middle-aged, healthy military men: Evidence for a critical role of optimal lipid levels

BACKGROUND

Modifying lipids levels underpins atherosclerosis prevention. Flow-mediated dilation (FMD) could advise which patients to treat and to what extent. Little is known about the influence of near-normal lipid levels on the endothelium and the mechanisms related to different lipid fractions. We studied associations between FMD and lipids, focusing on normal lipid levels.

METHODS

An age-homogeneous sample of 171 healthy, untreated military men (mean age 35.5+/-1.1 years) was studied: serum lipid determination and brachial artery ultrasound with a forearm ischemia cuff and automated measurement were performed. NCEP-ATP III groups were used.

RESULTS

Significantly smaller vessel diameters were found among individuals with high HDL-c (4.10 mm vs. 4.24 mm), optimal LDL-c (4.00 mm vs. 4.22 mm), and normal triglycerides (<150 mg/dl) (4.15 mm vs. 4.31 mm). Basal diameter correlated significantly with HDL-c and triglycerides. There were significant differences in FMD between low HDL-c compared to the rest (4.13% vs. 5.07%) and between optimal and near-optimal LDL-c compared to the rest (5.28% vs. 4.56%). HDL-c and LDL-c correlated with FMD. The inverse relation of high LDL-c and FMD is partially due to a decreased stimulus. Besides, stimulus heterogeneity may mask HDL-c link with FMD.

CONCLUSION

Those subjects naturally (not pharmacologically) in the healthy tail-end of the lipid distributions have the best endothelial function and smaller vessels. Functional vascular remodeling might precede anatomical remodeling and, in early stages, vessel size should be considered a risk indicator rather than an atherosclerotic sign. Furthermore, controlling the stimulus seems necessary for detecting the relationship between HDL-c and FMD, and should be performed regularly.

Metabolic syndrome and preclinical atherosclerosis: focus on femoral arteries

Several evidences revealed the relationship between the earliest stages of atherosclerosis and the components of metabolic syndrome. The aim of this study was to disclose preclinical atherosclerotic lesions in a cross-sectional observational study involving 147 patients with metabolic syndrome by the assessment of brachial flow-mediated vasodilation (FMV) and intima-media thickening at both carotid and femoral sites. The purpose was to investigate the association of this metabolic disorder with prevalent atherosclerotic damage in different vascular sites. A control group of 87 healthy subjects was also investigated. Patients had lower values of FMV and a higher mean intima-media thickness (IMT) at both the carotid and femoral sites with respect to controls. Flow-mediated vasodilation had a positive correlation with high-density lipoprotein (HDL) cholesterol and a negative one with low-density lipoprotein (LDL) cholesterol, glycemia, and insulinemia. Carotid mean IMT was directly related to LDL cholesterol and age, and inversely with HDL cholesterol; femoral mean IMT had a direct association with LDL cholesterol, triglycerides, glycemia, and insulinemia and an inverse correlation with HDL cholesterol and LDL size. LDL cholesterol, HDL cholesterol, insulin, and brachial artery diameter were predictive of brachial FMV (beta=-0.17, 0.21, -0.27, and -0.29, respectively; P<.05), whereas age, LDL cholesterol, and HDL cholesterol were independent predictors of mean carotid IMT (beta=0.19, 0.37, and -0.27, respectively; P<.05); on the other hand, LDL cholesterol, triglycerides, and insulin were independent predictors of mean femoral IMT (beta=0.32, 0.26, and 0.25, respectively; P<.05). In conclusion, the present study documented an altered endothelial function and intima-media thickening in patients with metabolic syndrome without overt cardiovascular disease. Moreover, it focused on the strong influence of metabolic syndrome on preclinical atherosclerotic lesions at the femoral site.

A high-fat meal is accompanied by increased plasma interleukin-6 concentrations

BACKGROUND AND AIM

Enhanced and prolonged postprandial lipaemia is associated with coronary heart disease (CHD). However, the mechanisms linking postprandial lipaemia to the increased risk of atherosclerosis and CHD remain to be determined. The aim of the present study was to examine the effects of a high-fat meal on plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) and cellular adhesion molecules in CHD patients and control subjects.

METHODS AND RESULTS

Forty-one middle-aged men with premature CHD and 26 healthy male controls were investigated. The plasma triglyceride response to the high-fat meal was significantly greater among cases than controls. The oral fat load induced a twofold increase in plasma concentrations of IL-6, an increase that was similar in CHD patients and control subjects. No changes could be detected in plasma concentrations of cellular adhesion molecules in response to postprandial lipaemia in either CHD patients or control subjects.

CONCLUSION

The results of the present study suggest that a high-fat meal affects mechanisms that induce increased inflammatory activity, which is recognised as a key modulator in the development of atherosclerosis and CHD. However, the increased levels of plasma IL-6 appear not to be determined by the magnitude of the postprandial triglyceridaemia.

Detailed exploration of the endothelium: parameterization of flow-mediated dilation through principal component analysis

Endothelial dysfunction is associated with cardiovascular diseases and their risk factors (CVRF), and flow-mediated dilation (FMD) is increasingly used to explore it. In this test, artery diameter changes after post-ischaemic hyperaemia are classically quantified using maximum peak vasodilation (FMDc). To obtain more detailed descriptors of FMD we applied principal component analysis (PCA) to diameter-time curves (absolute), vasodilation-time curves (relative) and blood-velocity-time curves. Furthermore, combined PCA of vessel size and blood-velocity curves allowed exploring links between flow and dilation. Vessel diameter data for PCA (post-ischaemic: 140 s) were acquired from brachial ultrasound image sequences of 173 healthy male subjects using a computerized technique previously reported by our team based on image registration (Frangi et al 2003 IEEE Trans. Med. Imaging 22 1458). PCA provides a set of axes (called eigenmodes) that captures the underlying variation present in a database of waveforms so that the first few eigenmodes retain most of the variation. These eigenmodes can be used to synthesize each waveform analysed by means of only a few parameters, as well as potentially any signal of the same type derived from tests of new patients. The eigenmodes obtained seemed related to visual features of the waveform of the FMD process. Subsequently, we used eigenmodes to parameterize our data. Most of the main parameters (13 out of 15) correlated with FMDc. Furthermore, not all parameters correlated with the same CVRF tested, that is, serum lipids (i.e., high LDL-c associated with slow vessel return to a baseline, while low HDL-c associated with a lower vasodilation in response to similar velocity stimulus), thus suggesting that this parameterization allows a more detailed and factored description of the process than FMDc.

Clinical importance and therapeutic modulation of small dense low-density lipoprotein particles

The National Cholesterol Education Programme Adult Treatment Panel III accepted the predominance of small dense low-density lipoprotein (sdLDL) as an emerging cardiovascular disease (CVD) risk factor. Most studies suggest that measuring low-density lipoprotein (LDL) particle size, sdLDL cholesterol content and LDL particle number provides additional assessment of CVD risk. Therapeutic modulation of small LDL size, number and distribution may decrease CVD risk; however, no definitive causal relationship is established, probably due to the close association between sdLDL and triglycerides and other risk factors (e.g., high-density lipoprotein, insulin resistance and diabetes). This review addresses the formation and measurement of sdLDL, as well as the relationship between sdLDL particles and CVD. The effect of hypolipidaemic (statins, fibrates and ezetimibe) and hypoglycaemic (glitazones) agents on LDL size and distribution is also discussed.

Resistance exercise does not affect the serum concentrations of cell adhesion molecules

BACKGROUND

Cell adhesion molecules are proteins expressed on the surface of a variety of cells and mediate the leucocyte response to inflammation. Some of these molecules are released to the plasma as soluble forms, whose presence indicates the degree of vascular endothelial activation or dysfunction. Increased concentrations of soluble adhesion molecules are thought to hamper the immune response and mediate the atherosclerotic inflammatory process. Studies on the effect of exercise on the concentrations of soluble adhesion molecules have almost exclusively used aerobic exercise.

AIM

To assess the effect of resistance exercise on the serum concentrations of five cell adhesion molecules during and immediately after 30 min of exercise in lean and obese participants.

METHODS

Fourteen healthy young men (eight lean and six obese) performed 3 sets of 10 resistance exercises with 10-12 repetitions at 70-75% of one repetition maximum in a circuit training fashion. Venous blood samples were drawn at baseline and at the end of the first, second and third sets. The serum concentrations of vascular cell adhesion molecule-1, intercellular cell adhesion molecule-1, E-selectin, P-selectin and L-selectin were measured in a biochip array analyser.

RESULTS

No significant changes were observed in the concentrations of these cell adhesion molecules during exercise, or between lean and obese participants.

CONCLUSION

Our data indicate that resistance exercise of moderate to high intensity does not affect the serum concentrations of cell adhesion molecules in healthy young lean or obese men, suggesting no considerable negative effect on immune function.