The role of nitric oxide in endothelium-dependent vasodilation of hypercholesterolemic patients

The synergistic effect of obesity and dyslipidemia on hypertension: results from the STEPS survey

BACKGROUND

Obesity and dyslipidemia are important risk factors for hypertension (HTN). When these two conditions coexist, they may interact in a synergistic manner and increase the risk of developing HTN and its associated complications. The aim of this study was to investigate the synergistic effect of general and central obesity with dyslipidemia on the risk of HTN.

METHOD

Data from 40,387 individuals aged 25 to 64 years were obtained from a repeated cross-sectional study examining risk factors for non-communicable diseases (STEPS) in 2007, 2011 and 2016. Body mass index (BMI) was calculated as a measure of general obesity and waist circumference (WC) as a measure of central obesity. Dyslipidemia was defined as the presence of at least one of the lipid abnormalities. Hypertension was defined as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg or current use of antihypertensive medication. To analyze the synergistic effect between obesity and dyslipidemia and HTN, the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI) were calculated. A weighted logistic regression model was performed to estimate the odds ratios (ORs) for the risk of HTN.

RESULTS

The results showed an association between obesity, dyslipidemia and hypertension. The interaction between obesity and dyslipidemia significantly influences the risk of hypertension. In hypertensive patients, the presence of general obesity increased from 14.55% without dyslipidemia to 64.36% with dyslipidemia, while central obesity increased from 13.27 to 58.88%. This interaction is quantified by RERI and AP values of 0.15 and 0.06 for general obesity and 0.24 and 0.09 for central obesity, respectively. The corresponding SI of 1.11 and 1.16 indicate a synergistic effect. The OR also show that the risk of hypertension is increased in the presence of obesity and dyslipidemia.

CONCLUSION

Obesity and dyslipidemia are risk factors for HTN. In addition, dyslipidemia with central obesity increases the risk of HTN and has a synergistic interaction effect on HTN. Therefore, the coexistence of obesity and lipid abnormalities has many clinical implications and should be appropriately monitored and evaluated in the management of HTN.

Utilizing venous occlusion plethysmography to assess vascular effects: A study with buloxibutid, an angiotensin II type 2 receptor agonist

Buloxibutid (also known as C21) is a potent and selective angiotensin II type 2 receptor (AT2R) agonist, in development for oral treatment of fibrotic lung disease. This phase I, open-label, pharmacodynamic study investigated vascular effects of buloxibutid in five healthy male volunteers. Subjects were administered intra-arterial infusions of buloxibutid for 5 min in ascending doses of 3, 10, 30, 100, and 200 μg/min, infused sequentially in the forearm. Infusions of sodium nitroprusside (SNP) solution in doses of 0.8-3.2 μg/min were administered as a positive control. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. Safety and tolerability of intra-arterial administrations of buloxibutid were evaluated. Following infusion of buloxibutid in doses of 3-200 μg/min, the range of increase in FBF was 27.8%, 17.2%, 37.0%, 28.5%, and 60.5%, compared to the respective baseline. The largest increase was observed in the highest dose group. Infusions of SNP as a positive control, increased FBF 230-320% compared to baseline. Three adverse events (AEs) of mild intensity, not related to buloxibutid or SNP, were reported for two subjects. Two of these AEs were related to study procedures. There were no clinically relevant changes in arterial blood pressure during the study period. Intra-arterial infusion of buloxibutid in low, ascending doses increased FBF, indicating that buloxibutid may be effective in conditions associated with endothelial dysfunction. Venous occlusion plethysmography was found to be a useful method to explore pharmacodynamic vascular effects of novel AT2R agonists, while avoiding systemic adverse effects.

Studies on the Effects of Hypercholesterolemia on Mouse Ophthalmic Artery Reactivity

Atherogenic lipoproteins may impair vascular reactivity, leading to tissue damage in various organs, including the eye. This study aimed to investigate whether ophthalmic artery reactivity is affected in mice lacking the apolipoprotein E gene (ApoE-/-), a model for hypercholesterolemia and atherosclerosis. Twelve-month-old male ApoE-/- mice and age-matched wild-type controls were used to assess vascular reactivity using videomicroscopy. Moreover, the vascular mechanics, lipid content, levels of reactive oxygen species (ROS), and expression of pro-oxidant redox enzymes and the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were determined in vascular tissue. Unlike the aorta, the ophthalmic artery of ApoE-/- mice developed no signs of endothelial dysfunction and no signs of excessive lipid deposition. Remarkably, the levels of ROS, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NOX2, NOX4, and LOX-1 were increased in the aorta but not in the ophthalmic artery of ApoE-/- mice. Our findings suggest that ApoE-/- mice develop endothelial dysfunction in the aorta by increased oxidative stress via the involvement of LOX-1, NOX1, and NOX2, whereas NOX4 may participate in media remodeling. In contrast, the ophthalmic artery appears to be resistant to chronic apolipoprotein E deficiency. A lack of LOX-1 expression/overexpression in response to increased oxidized low-density lipoprotein levels may be a possible mechanism of action.

Dual pathway inhibition as compared to acetylsalicylic acid monotherapy in relation to endothelial function in peripheral artery disease, a phase IV clinical trial

Objective

Dual pathway inhibition (DPI) by combining acetylsalicylic acid (ASA) with low-dose rivaroxaban has been shown to reduce cardiovascular events in patients with peripheral arterial disease (PAD) when compared to ASA monotherapy. A potential explanation is that inhibition of factor Xa improves endothelial function through crosstalk between coagulation and inflammatory pathways, subsequently attenuating the occurrence of cardiovascular events. We hypothesize that the addition of rivaroxaban to ASA in PAD patients leads to improved endothelial function.

Design

An investigator-initiated, multicentre trial investigating the effect of DPI on endothelial function.

Methods

Patients, diagnosed with PAD, were enrolled in two cohorts: cohort A (Rutherford I-III) and cohort B (Rutherford IV-VI). Participants received ASA monotherapy for a 4-weeks run-in period, followed by 12 weeks of DPI. Macro- and microvascular endothelial dysfunction were studied by measuring carotid artery reactivity upon sympathetic stimulus and by measuring plasma endothelin-1 concentrations, respectively. All measurements were performed during the use of ASA (baseline) and after 12 weeks of DPI.

Results

159 PAD patients (111 cohort A, 48 cohort B) were enrolled. Twenty patients discontinued study drugs early. Carotid artery constriction upon sympathetic stimulation at baseline (ASA) and after 12 weeks of DPI was similar in the total group, 22.0 vs. 22.7% (p = 1.000), and in the subgroups (Cohort A 22.6 vs. 23.7%, p = 1.000; cohort B 20.5 vs. 20.5%, p = 1.000), respectively. The mean concentration of plasma endothelin-1 at baseline and after 12 weeks of DPI did not differ, 1.70 ± 0.5 vs. 1.66 ± 0.64 pmol/L (p = 0.440) in the total group, 1.69 ± 0.59 vs. 1.62 ± 0.55 pmol/L in cohort A (p = 0.202), and 1.73 ± 0.53 vs. 1.77 ± 0.82 pmol/L in cohort B (p = 0.682), respectively.

Conclusion

Macro- and microvascular endothelial dysfunction, as reflected by carotid artery reactivity and plasma endothelin-1 concentrations, are not influenced in PAD patients by addition of low-dose rivaroxaban to ASA monotherapy for 12 weeks.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT04218656.

Simvastatin is Efficacious in Treating Cirrhosis: A Meta-analysis

BACKGROUND

Statins can improve prognosis of patients with liver cirrhosis by suppressing inflammation and lowering portal pressure. Here, we performed a meta-analysis to evaluate the clinical efficacy of simvastatin in liver cirrhosis patients.

METHODS

We searched PubMed, EMBASE, and Cochrane library databases for randomized controlled trials targeting simvastatin in patients with liver cirrhosis. The primary and secondary outcomes were the efficacy of simvastatin on clinical outcomes and its safety, respectively.

RESULTS

A total of 554 relevant articles were downloaded, of which 9 (comprising 648 participants) were eligible and were finally included in the analysis. Four studies revealed the impact of simvastatin on patient mortality, with the overall death rate found to be significantly lower in the simvastatin relative to the control group [risk ratio (RR): 0.46; 95% confidence interval (CI), 0.29 to 0.73; P <0.01]. Further analysis of the cause of death showed that simvastatin significantly reduces incidence of fatal bleeding (RR: 0.35; 95% CI, 0.13 to 0.95; P =0.04), as well as cholesterol [mean difference (MD): -31.48; 95% CI, -52.80 to -10.15; P <0.01] and triglyceride (MD: -25.88; 95% CI, -49.90 to -1.86; P =0.03) levels. At the same time, simvastatin did not significantly elevate levels of alanine aminotransferase (ALT) (MD: 2.34; 95% CI, -31.00 to 35.69; P =0.89) and was not associated with incidence of other side effects.

CONCLUSIONS

The use of simvastatin in cirrhotic patients lowers mortality rates by suppressing incidences of fatal bleeding.

Dyslipidemia Increases the Risk of Incident Hypertension in a Large Taiwanese Population Follow-Up Study

Dyslipidemia is an important risk factor for hypertension and is strongly associated with an elevated risk of cardiovascular diseases including atherosclerosis and stroke. In this study, we investigated correlations between lipid profiles, including triglycerides, total cholesterol (Chol), high-and low-density lipoprotein cholesterol (HDL-C/LDL-C), and Chol/HDL-C, and baseline and incident hypertension. A total of 26,965 subjects with 4 years of follow-up data were enrolled from the Taiwan Biobank. In the cross-sectional cohort, associations between the prevalence of hypertension and lipid profiles were examined in all study participants (n = 26,965). In the longitudinal cohort, these associations were further assessed in the participants without baseline hypertension (n = 21,454). Multivariable analysis revealed that those in the second quartile (Q2) of triglycerides (compared to Q1; odds ratio (OR), 1.402; p < 0.001); Q3 of triglycerides (compared to Q1; OR, 1.365; p < 0.001); Q4 of triglycerides (compared to Q1; OR, 1.617; p < 0.001); Q3 of HDL-C (compared to Q1; OR, 0.886; p = 0.042); Q4 of HDL-C (compared to Q1; OR, 0.819; p = 0.002); Q2 of Chol/HDL-C (compared to Q1; OR, 1.144; p = 0.042); Q3 of Chol/HDL-C (compared to Q1; OR, 1.149; p = 0.034); and Q4 of Chol/HDL-C (compared to Q1; OR, 1.225; p = 0.002) were significantly associated with incident hypertension. In summary, high Chol/HDL-C, low HDL-C, and high triglycerides were associated with a higher risk of incident hypertension in the enrolled Taiwanese participants.

Sex Differences in Vascular Aging and Impact of GPER Deletion

Aging is a nonmodifiable risk factor for cardiovascular disease associated with arterial stiffening and endothelial dysfunction. We hypothesized that sex differences exist in vascular aging processes and would be attenuated by global deletion of the G protein-coupled estrogen receptor. Blood pressure was measured by tail cuff plethysmography, pulse wave velocity (PWV) and echocardiography were assessed with high resolution ultrasound, and small vessel reactivity was measured using wire myography in adult (25 weeks) and middle-aged (57 weeks) male and female mice. Adult female mice displayed lower blood pressure and PWV, but this sex difference was absent in middle-aged mice. Aging significantly increased PWV but not blood pressure in both sexes. Adult female carotids were more distensible than males, but this sex difference was lost during aging. Acetylcholine-induced relaxation was greater in female than male mice at both ages, and only males showed aging-induced changes in cardiac hypertrophy and function. GPER deletion removed the sex difference in PWV as well as ex vivo stiffness in adult mice. The sex difference in blood pressure was absent in KO mice and was associated with endothelial dysfunction in females. These findings indicate that the impact of aging on arterial stiffening and endothelial function is not the same in male and female mice. Moreover, nongenomic estrogen signaling through GPER impacted vascular phenotype differently in male and female mice. Delineating sex differences in vascular changes during healthy aging is an important first step in improving early detection and sex-specific treatments in our aging population.

Relationship Between Lipid Profiles and Hypertension: A Cross-Sectional Study of 62,957 Chinese Adult Males

Background

Patterns of dyslipidemia and incidence of hypertension have been rarely reported in Asian populations with inconsistent findings. To accumulate further evidence in Asian populations, the study aimed to investigate the relationship between lipid profiles and hypertension in Chinese adult males.

Methods

We conducted a cross-sectional study based on the data from the DATADRYAD database. The overall population was divided into hypertensive and non-hypertensive groups based on baseline blood pressure levels. For continuous variables, Mann-Whitney test was performed between two groups, while Kruskal-Wallis and Dunn tests were used among multiple groups. The chi-square test was carried out for dichotomous variables. Spearman's correlation coefficient was employed to assess the association between systolic blood pressure (SBP), diastolic blood pressure (DBP) and lipid profiles, whereas the relationship between lipid profiles and the incidence of hypertension was evaluated using multivariate logistic regression. The Bayesian network (BN) model was adopted to investigate the relationship between clinical characteristics and hypertension, and the importance of related predictor to the incidence of hypertension was obtained to make conditional probability analysis.

Results

Finally, totally 62,957 participants were included in this study. In the lipid profiles, total cholesterol (TC), low-density cholesterol (LDL-c), and non- high-density lipoprotein cholesterol (non-HDL-c) were higher in the hypertensive population (p <0.001). In the fully multivariate model, for every 1 mg/dl increase in TC, LDL-c and non-HDL, the risk of hypertension increased by 0.2% [1.002 (1.001–1.003)], 0.1% [1.001 (1.000–1.002)], and 0.1% [1.001 (1.000–1.002)]. Meanwhile, HDL-c became positively associated with the incidence of hypertension (p for trend < 0.001) after adjusting for the body mass index (BMI), and 1 mg/dl increment in HDL-c increased the risk of hypertension by 0.2% [1.002 (1.000–1.002)] after fully adjusting for multiple variables. Furthermore, the BN showed that the importance of age, BMI, fasting plasma glucose (FPG), and TC to the effect of hypertension is 43.3, 27.2, 11.8, and 5.1%, respectively.

Conclusion

Elevated TC, LDL-c, and non-HDL-c were related to incidence of hypertension in Chinese adult males, whereas triglycerides (TG) was not significantly associated. The relationship between HDL-c and hypertension incidence shifted from no association to a positive correlation after adjusting for the BMI. Moreover, the BN model displayed that age, the BMI, FPG, and TC were strongly associated with hypertension incidence.

Pathophysiology of Atherosclerosis

Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.

The relationship between lipid risk score and new-onset hypertension in a prospective cohort study

BACKGROUND

Dyslipidemia and hypertension are both important risk factors for atherosclerotic cardiovascular diseases. However, the relationship between dyslipidemia and incident hypertension remains to be elucidated comprehensively. The main purpose of this study was to construct the lipid risk score to explore the risk prediction effect of integrated lipid indices on new-onset hypertension.

METHODS

This prospective cohort study with 2116 non-hypertensive subjects was conducted from 2009 to 2020. New hypertension events during the follow-up period were recorded and verified. The lipid risk score was calculated by summing coded total cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol weighted with corresponding effect sizes. Cox regression analysis was used to estimate the association between the lipid risk score or lipid indices and incident hypertension in the subgroup of age (< 55 and≥ 55 years at baseline).

RESULTS

After a median of 10.75-year follow-up, 637 incident hypertension cases were identified. The restricted cubic spline showed that the lipid risk score had a positive linear correlation with hypertension (P< 0.001). Among people< 55 years, with every increase of 0.94 in lipid risk score, the risk of hypertension increased by 37% (adjusted HR [95%CI]: 1.369 [1.164-1.610]). This association was not modified by overweight or obesity.

CONCLUSIONS

The integrated lipid risk score, independent of traditional risk factors, has a significantly predictive effect on hypertension in people younger than 55 years. This finding may aid in identifying high-risk individuals for hypertension, as well as facilitating early intervention and management to reduce adverse cardiovascular events. Comprehensive lipid management should be attached importance in the prevention and control of hypertension.

Cholesterol-Induced Suppression of Endothelial Kir Channels Is a Driver of Impairment of Arteriolar Flow-Induced Vasodilation in Humans

Dyslipidemia-induced endothelial dysfunction is an important factor in the progression of cardiovascular disease; however, the underlying mechanisms are unclear. Our recent studies demonstrated that flow-induced vasodilation (FIV) is regulated by inwardly rectifying K⁺ channels (Kir2.1) in resistance arteries. Furthermore, we showed that hypercholesterolemia inhibits Kir2.1-dependent vasodilation. In this study, we introduced 2 new mouse models: (1) endothelial-specific deletion of Kir2.1 to demonstrate the role of endothelial Kir2.1 in FIV and (2) cholesterol-insensitive Kir2.1 mutant to determine the Kir2.1 regulation in FIV under hypercholesterolemia. FIV was significantly reduced in endothelial-specific Kir2.1 knock-out mouse mesenteric arteries compared with control groups. In cholesterol-insensitive Kir2.1 mutant mice, Kir2.1 currents were not affected by cyclodextrin and FIV was restored in cells and arteries, respectively, with a hypercholesterolemic background. To extend our observations to humans, 16 healthy subjects were recruited with LDL (low-density lipoprotein)-cholesterol ranging from 51 to 153 mg/dL and FIV was assessed in resistance arteries isolated from gluteal adipose. Resistance arteries from participants with >100 mg/dL LDL (high-LDL) exhibited reduced FIV as compared with those participants with <100 mg/dL LDL (low-LDL). A significant negative correlation was observed between LDL cholesterol and FIV in high-LDL. Expressing dominant-negative Kir2.1 in endothelium blunted FIV in arteries from low-LDL but had no further effect on FIV in arteries from high-LDL. The Kir2.1-dependent vasodilation more negatively correlated to LDL cholesterol in high-LDL. Overexpressing wild-type Kir2.1 in endothelium fully recovered FIV in arteries from participants with high-LDL. Our data suggest that cholesterol-induced suppression of Kir2.1 is a major mechanism underlying endothelial dysfunction in hypercholesterolemia.

Off-Target Effects of Antidepressants on Vascular Function and Structure

Depression emerges as a risk factor for cardiovascular disease, and it is thought that successful antidepressant treatment may reduce such a risk. Therefore, antidepressant treatment embodies a potential preventive measure to reduce cardiovascular events in patients with depression. Accumulating evidence indicates that antidepressants have off-target effects on vascular dysfunction and in the early stages of atherosclerosis, which form the basis for cardiovascular disease (CVD) pathogenesis. In this context, we performed a thorough review of the evidence pertaining to the effects of different classes of antidepressant medications on hemodynamic and early atherosclerosis markers. The preclinical and clinical evidence reviewed revealed a preponderance of studies assessing selective serotonin reuptake inhibitors (SSRI), whereas other classes of antidepressants are less well-studied. Sufficient evidence supports a beneficial effect of SSRIs on vascular inflammation, endothelial function, arterial stiffening, and possibly delaying carotid atherosclerosis. In clinical studies, dissecting the hypothesized direct beneficial antidepressant effect of SSRIs on endothelial health from the global improvement upon remission of depression has proven to be difficult. However, preclinical studies armed with appropriate control groups provide evidence of molecular mechanisms linked to endothelial function that are indeed modulated by antidepressants. This suggests at least a partial direct action on vascular integrity. Further research on endothelial markers should focus on the effect of antidepressants on treatment responders versus non-responders in order to better ascertain the possible beneficial vascular effects of antidepressants, irrespective of the underlying course of depression.

Sustained inflammation, coagulation activation and elevated endothelin-1 levels without macrovascular dysfunction at 3 months after COVID-19

INTRODUCTION

Endothelial damage and thrombosis caused by COVID-19 may imperil cardiovascular health. More than a year since the WHO declared COVID-19 pandemic, information on its effects beyond the acute phase is lacking. We investigate endothelial dysfunction, coagulation and inflammation, 3 months post-COVID-19.

MATERIALS AND METHODS

A cohort study was conducted including 203 patients with prior COVID-19. Macrovascular dysfunction was assessed by measuring the carotid artery diameter in response to hand immersion in ice-water. A historic cohort of 312 subjects served as controls. Propensity score matching corrected for baseline differences. Plasma concentrations of endothelin-1 were measured in patients post-COVID-19, during the acute phase, and in matched controls. Coagulation enzyme:inhibitor complexes and inflammatory cytokines were studied.

RESULTS AND CONCLUSIONS

The prevalence of macrovascular dysfunction did not differ between the COVID-19 (18.6%) and the historic cohort (22.5%, RD -4%, 95%CI: -15-7, p = 0.49). Endothelin-1 levels were significantly higher in acute COVID-19 (1.67 ± 0.64 pg/mL) as compared to controls (1.24 ± 0.37, p < 0.001), and further elevated 3 months post-COVID-19 (2.74 ± 1.81, p < 0.001). Thrombin:antithrombin(AT) was high in 48.3%. Markers of contact activation were increased in 16-30%. FVIIa:AT (35%) and Von Willebrand Factor:antigen (80.8%) were elevated. Inflammatory cytokine levels were high in a majority: interleukin(IL)-18 (73.9%), IL-6 (47.7%), and IL-1ra (48.9%). At 3 months after acute COVID-19 there was no indication of macrovascular dysfunction; there was evidence, however, of sustained endothelial cell involvement, coagulation activity and inflammation. Our data highlight the importance of further studies on SARS-CoV-2 related vascular inflammation and thrombosis, as well as longer follow-up in recovered patients.

Circadian Control of Sodium and Blood Pressure Regulation

The attention for the control of dietary risk factors involved in the development of hypertension, includes a large effort on dietary salt restrictions. Ample studies show the beneficial role of limiting dietary sodium as a lifestyle modification in the prevention and management of essential hypertension. Not until the past decade or so have studies more specifically investigated diurnal variations in renal electrolyte excretion, which led us to the hypothesis that timing of salt intake may impact cardiovascular health and blood pressure regulation. Cell autonomous molecular clocks as the name implies, function independently to maintain optimum functional rhythmicity in the face of environmental stressors such that cellular homeostasis is maintained at all times. Our understanding of mechanisms influencing diurnal patterns of sodium excretion and blood pressure has expanded with the discovery of the circadian clock genes. In this review, we discuss what is known about circadian regulation of renal sodium handling machinery and its influence on blood pressure regulation, with timing of sodium intake as a potential modulator of the kidney clock.

Reduced global longitudinal strain at rest and inadequate blood pressure response during exercise treadmill testing in male heterozygous familial hypercholesterolemia patients

Background

Heterozygous familial hypercholesterolemia (heFH) is a genetic disorder leading to premature coronary artery disease (CAD). We hypothesized that the subclinical pathophysiologic consequences of hypercholesterolemia may be detected before the occurrence of clinically overt CAD by stress testing and myocardial strain imaging.

Patients-methods

We evaluated the treadmill tests (ETTs) of 46 heFH men without known arterial hypertension/diabetes mellitus/vasculopathy like CAD and of 39 healthy men matched for age, baseline systolic/diastolic blood pressure (BP) and heart rate (HR), using Bruce protocol. Global longitudinal strain (GLS) of the left ventricle (LV) additionally to ejection fraction was obtained.

Results

heFH men reached a significantly higher peak systolic and diastolic BP compared to controls (p = 0.002 and p < 0.001, respectively). Mean rate pressure product was significantly higher in heFH patients (p = 0.038). Both duration of the ETT and workload in metabolic equivalents was lower in the heFH group (p < 0.001 and p < 0.001, respectively). Baseline to peak rise of systolic and diastolic BP in heFH men was higher (p = 0.008 and p < 0.001 for systolic and diastolic BP, respectively). Furthermore, heFH men had higher rise of HR from baseline to peak, compared to controls; (p = 0.047). GLS in heHF men was slightly decreased (p = 0.014), although the ejection fraction was similar in both groups.

Conclusion

heFH men have a higher rise in systolic/diastolic BP during ETT, which may reflect early, preclinical hypertension. Furthermore, slight impairment of LV GLS is present, despite the absence of apparent myocardial dysfunction in conventional 2D echocardiography.

Lipid profiles and the risk of new-onset hypertension in a Chinese community-based cohort

BACKGROUND AND AIMS

Dyslipidemia and hypertension, key risk factors for cardiovascular disease, may share similar pathophysiological processes. A longitudinal association was reported between dyslipidemia and new-onset hypertension, but few data were published in Asian. We aimed to investigate the association of lipid profiles with new-onset hypertension in a Chinese community-based non-hypertensive cohort without lipid-lowering treatment (n = 1802).

METHODS AND RESULTS

New-onset hypertension was defined as any self-reported history of hypertension, systolic blood pressure ≥140 mmHg, or diastolic blood pressure ≥90 mmHg, or receiving antihypertensive medications at follow-up. Logistic regression models were used to evaluate the associations. Participants were aged 53.97 ± 7.49 years, 31.19% were men, and 64.54% with dyslipidemia. During a median of 2.30 years follow-up, the incidence of new-onset hypertension was 12.99%. Multivariate adjusted risks of new-onset hypertension increased with triglyceride increases (odds ratio [OR] = 1.14, 95% confidence interval [CI]: 1.03-1.27) and high-density lipoprotein cholesterol (HDL-C) decreases (OR = 0.47, 95% CI: 0.29-0.76) for one unit. However, threshold effects were observed for total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and non-HDL-C. Compared with subjects with hyperlipidemia, in those with normal concentrations of TC, LDL-C, and non-HDL-C increased risks of new-onset hypertension were observed with OR (95% CI) of 1.65 (1.10-2.46), 1.58 (1.07-2.33), and 1.57 (1.15-2.15) for one unit increasement, respectively, after adjusting for all covariates.

CONCLUSION

Higher TG and lower HDL-C increased the risk of new-onset hypertension, but for TC, LDL-C and non-HDLC, the risk of new-onset hypertension was increased only at normal concentrations in a Chinese community-based cohort.

Comparative study of microvascular function: Forearm blood flow versus dynamic retinal vessel analysis

OBJECTIVE

Recently, dynamic retinal vessel analysis (DVA) has gained interest for investigation of microvascular function but comparative measurements with standard methods like the forearm blood flow technique (FBF) are uncommon till now.

METHODS

We recruited 23 high-risk cardiovascular patients (Risk) and 17 healthy persons (Ctrl). During the FBF experiment, postocclusive reactive hyperaemia (RH) as well as endothelium-dependent and independent vasodilation was measured by infusion of acetylcholine (ACh) and sodium nitroprusside (SNP) into the brachial artery. The dynamic vessel analyzer was applied for measurement of the retinal arterial and venous response to flickering light during DVA and for determination of the central retinal arterial (CRAE) and venous equivalent (CRVE).

RESULTS

Forearm blood flow technique was significantly attenuated in the patient group during postocclusive RH (p < .005). The increase of FBF in response to SNP did not differ significantly between the two groups (p = .09). In contrast, the FBF response to ACh was significantly blunted in the patient group (p < .05), indicating endothelial dysfunction. DVA did not detect any difference of retinal arterial (p = .68) or retinal venous (p = .93) vasodilation between both groups. The CRAE (p = .55) and CRVE (p = .83) did not differ significantly in either group.

CONCLUSIONS

Forearm blood flow and DVA cannot be regarded as equivalent methods for testing of microvascular function. Possible explanations include differences in the vascular beds and vessel diameters examined as well as differences in the trigger mechanisms applied. Further studies are needed to define the role of DVA in this context.

Endothelial function improvement in patients with familial hypercholesterolemia receiving PCSK-9 inhibitors on top of maximally tolerated lipid lowering therapy

BACKGROUND

Treatment with protein convertase subtilisin kexin type 9 inhibitors (PCSK-9i) reduced cholesterol levels and cardiovascular events in patients with hypercholesterolemia. We assessed changes in lipid profile, oxidation markers and endothelial function in patients with familial hypercholesterolemia (FH) after a 12-week treatment with a PCSK-9i.

METHODS

Patients with FH starting a treatment with PCSK-9i were included. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), lipoprotein(a) (Lp(a)), small dense LDL (assessed by LDL score), 11-dehydro-thromboxane (11-TXB2), 8-isoprostaglandin-2alpha (8-iso-PGF2α), flow-mediated dilation (FMD) and reactive hyperaemia index (RHI) were evaluated before starting PCSK-9i treatment and after a 12-week treatment.

RESULTS

Twenty-five subjects were enrolled (52% males, mean age 51.5 years). At the 12-week assessment, we observed a 38% median reduction in TC, 52% in LDL-C, 7% in Lp(a) and 46% in LDL score. In parallel, 11-TXB2 and 8-iso-PGF2α showed a reduction of 18% and 17%, respectively. FMD changed from 4.78% ± 2.27 at baseline to 10.6% ± 5.89 at 12 weeks (p < 0.001), with RHI changing from 2.37 ± 1.23 to 3.76 ± 1.36 (p < 0.001). A multivariate analysis showed that, after adjusting for potential confounders, change in LDL score was an independent predictor of changes in FMD (β = -0.846, p = 0.015) and in 8-iso-PGF2α (β = 0.778, p = 0.012).

CONCLUSIONS

Small dense LDL reduction (assessed by LDL score) is related to changes in oxidation markers and endothelial function in patients with FH treated with PCSK-9i.

The Associations between Liver Enzymes and Cardiovascular Risk Factors in Adults with Mild Dyslipidemia

Hypertension and dyslipidemia often occur as comorbidities, with both being strong risk factors for developing cardiovascular diseases (CVD). Abnormal liver function test could reflect a potential CVD risk even in patients with mild dyslipidemia. The aim of this study was to assess the compounding relationship between liver enzymes and cardiovascular risk factors in subjects with mild dyslipidemia. The present analysis was performed among 438 participants who had enrolled in at least one of the nine clinical studies done at the Chonbuk National University Hospital between 2009 and 2019. Significant linear increasing trends were observed in blood pressure level and other cardiovascular risk factors across quartiles of serum γ-glutamyltransferase (GGT) or alanine aminotransferase (ALT), with the increment in hypertension prevalence occurring across the quartiles of GGT and ALT. On multivariate logistic regression analyses, the odds ratios for hypertension, adjusted for smoking, drinking and obesity, in the highest quartiles of GGT, ALT, aspartate aminotransferase, and alkaline phosphatase were 3.688, 1.617, 1.372, and 1.166, respectively. Our study indicates that GGT is a superior marker for predicting CVD risk among liver enzymes. Routine screening of plasma GGT levels in patients with mild dyslipidemia will allow for early detection of CVD.

Caveolin-1 in Stroke Neuropathology and Neuroprotection: A Novel Molecular Therapeutic Target for Ischemic-Related Injury

Cardiovascular disease and associated cerebral stroke are a global epidemic attributed to genetic and epigenetic factors, such as diet, life style and an increasingly sedentary existence due to technological advances in both the developing and developed world. There are approximately 5.9 million stroke-related deaths worldwide annually. Current epidemiological data indicate that nearly 16.9 million people worldwide suffer a new or recurrent stroke yearly. In 2014 alone, 2.4% of adults in the United States (US) were estimated to experience stroke, which is the leading cause of adult disability and the fifth leading cause of death in the US There are 2 main types of stroke: Hemorrhagic (HS) and ischemic stroke (IS), with IS occurring more frequently. HS is caused by intra-cerebral hemorrhage mainly due to high blood pressure, while IS is caused by either embolic or thrombotic stroke. Both result in motor impairments, numbness or abnormal sensations, cognitive deficits, and mood disorders (e.g. depression). This review focuses on the 1) pathophysiology of stroke (neuronal cell loss, defective blood brain barrier, microglia activation, and inflammation), 2) the role of the membrane protein caveolin- 1 (Cav-1) in normal brain physiology and stroke-induced changes, and, 3) we briefly discussed the potential therapeutic role of Cav-1 in recovery following stroke.

In vitro and in vivo evaluation of 3D bioprinted small-diameter vasculature with smooth muscle and endothelium

The ability to fabricate perfusable, small-diameter vasculature is a foundational step toward generating human tissues/organs for clinical applications. Currently, it is highly challenging to generate vasculature integrated with smooth muscle and endothelium that replicates the complexity and functionality of natural vessels. Here, a novel method for directly printing self-standing, small-diameter vasculature with smooth muscle and endothelium is presented through combining tailored mussel-inspired bioink and unique 'fugitive-migration' tactics, and its effectiveness and advantages over other methods (i.e. traditional alginate/calcium hydrogel, post-perfusion of endothelial cells) are demonstrated. The biologically inspired, catechol-functionalized, gelatin methacrylate (GelMA/C) undergoes rapid oxidative crosslinking in situ to form an elastic hydrogel, which can be engineered with controllable mechanical strength, high cell/tissue adhesion, and excellent bio-functionalization. The results demonstrate the bioprinted vascular construct possessed numerous favorable, biomimetic characteristics such as proper biomechanics, higher tissue affinity, vascularized tissue manufacturing ability, beneficial perfusability and permeability, excellent vasculoactivity, and in vivo autonomous connection (∼2 weeks) as well as vascular remodeling (∼6 weeks). The advanced achievements in creating biomimetic, functional vasculature illustrate significant potential toward generating a complicated vascularized tissue/organ for clinical transplantation.

Microvascular endothelial dysfunction in rheumatoid arthritis

The systemic autoimmune disease rheumatoid arthritis (RA) is characterized by increased cardiovascular mortality and morbidity and is an independent cardiovascular risk factor. Cardiovascular diseases (CVDs) result from accelerated atherogenesis, which is a consequence of endothelial dysfunction in the early stages of the disease. Endothelial dysfunction is a functional and reversible alteration of endothelial cells and leads to a shift in the properties of the endothelium towards reduced vasodilation, a pro-inflammatory state, and proliferative and prothrombotic properties. In RA, endothelial dysfunction can occur in the large vessels (such as the conduit arteries) and in the small vessels of the microvasculature, which supply oxygen and nutrients to the tissue and control inflammation, repair and fluid exchange with the surrounding tissues. Growing evidence suggests that microvascular endothelial dysfunction contributes to CVD development, as it precedes and predicts the development of conduit artery atherosclerosis and associated risk factors. As such, numerous studies have investigated microvascular endothelial dysfunction in RA, including its link with disease activity, disease duration and inflammation, the effect of treatments on endothelial function, and possible circulating biomarkers of microvascular endothelial dysfunction. Such findings could have important implications in the cardiovascular risk management of patients with RA.

Peripheral Microvascular Function Reflects Coronary Vascular Function

Objectives- Coronary endothelial dysfunction is a precursor of atherosclerosis and adverse outcomes. Whether endothelial dysfunction is a localized or generalized phenomenon in humans remains uncertain. We simultaneously measured femoral and coronary vascular function with the hypothesis that peripheral vascular endothelial function will be reflective of coronary endothelial function. Approach and Results- Eighty-five subjects underwent coronary angiography for evaluation of chest pain or abnormal stress tests. Endothelium-dependent and -independent vascular function were measured using intracoronary and intrafemoral infusions of acetylcholine and sodium nitroprusside, respectively. Coronary flow reserve was assessed using intracoronary adenosine infusion. Flow velocity was measured in each circulation using a Doppler wire (FloWire, EndoSonics). Coronary vascular resistance and femoral vascular resistance were calculated as mean arterial pressure (mm Hg)/coronary blood flow (mL/min) and mean arterial pressure (mm Hg)/femoral average peak velocity (cm/s), respectively. Mean age was 53±11 years, 37% were female, 44% had hypertension, 12% had diabetes mellitus, and 38% had obstructive coronary artery disease. There was a correlation between the change in femoral vascular resistance with acetylcholine and acetylcholine-mediated changes in both the coronary vascular resistance ( r=0.27; P=0.014) and in the epicardial coronary artery diameter ( r=-0.25; P=0.021), indicating that subjects with normal endothelial function in the femoral circulation had normal endothelial function in the coronary epicardial and microcirculation and vice versa. The coronary vasodilator response to adenosine also correlated with the femoral vasodilatation with acetylcholine ( r=0.4; P=0.0002). There was no correlation between the coronary and femoral responses to sodium nitroprusside. Conclusions- Endothelial functional changes in the peripheral and coronary circulations were modestly correlated. Thus, peripheral microvascular endothelial function reflects endothelium-dependent coronary epicardial and microvascular function and the coronary flow reserve. Visual Overview- An online visual overview is available for this article.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Joint interaction effect of metabolic syndrome and obstructive sleep apnea on hypertension

Numerous studies have observed a relationship between obstructive sleep apnea and hypertension, but the effects of metabolic syndrome on hypertension, and their interaction with obstructive sleep apnea, remain unclear. For this study, a total of 2972 patients were recruited from the Shanghai Sleep Health Study. Data from overnight polysomnography parameters, serum lipids, fasting blood glucose, blood pressure, and anthropometric measurements were collected. The authors then explored the independent associations and multiplicative and additive interactions of predictors of metabolic syndrome with hypertension. A positive dose-response relationship was observed between systolic blood pressure and diastolic blood pressure and quartiles of fasting glucose, triglyceride, low-density lipoprotein cholesterol, body mass index, and apnea-hypopnea index. Furthermore, logistic regression analysis showed that, in men, a high triglyceride level, hyperglycemia, and overweight status (and their interaction effect on obstructive sleep apnea) were associated with hypertension. Being overweight and hyperglycemic may markedly augment the adverse effect of obstructive sleep apnea on hypertension in men. Therefore, hypertension therapy should be individualized based on the specific comorbidities of each patient.

Improved endothelial function after short-term therapy with evolocumab

BACKGROUND

The reduction of cholesterol levels with cholesterol-lowering therapy may improve endothelial function. Lipid-lowering therapy has been greatly enhanced by the introduction of proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies. Less is known of the effect of PCSK9 inhibitors on endothelial function of subjects with hypercholesterolemia.

OBJECTIVE

To assess whether treatment with PCSK9 inhibitors may improve endothelial function evaluated by brachial artery vasoreactivity test.

METHODS

Brachial artery vasoreactivity test was performed in 14 consecutive patients with previous myocardial infarction before and after 2 months of therapy with evolocumab 140 mg twice in a month. Mean brachial artery diameter, velocity time integral, flow-mediated dilation (FMD) and low-density lipoprotein (LDL) cholesterol levels were also evaluated.

RESULTS

After 2 months of treatment with evolocumab, mean total cholesterol levels decreased from 245 ± 41 to 128 ± 30 mg/dL (P < .001, -48%), and LDL levels from 176 ± 43 to 71 ± 26 mg/dL (P = .001, -59%); FMD conversely increased from 6.3 ± 4.1% to 8.8 ± 6.3% (P = .004, +40%). Improvement in FMD was proportional to reduction of LDL levels (r = 0.69, P = .006). Therapy with evolocumab increased brachial artery diameter during vasoreactivity test (peak values 0.39 ± 0.09 vs 0.36 ± 0.11 cm, P = .010; final values 0.36 ± 0.10 vs 0.34 ± 0.10 cm, P = .001), and velocity time integral (peak levels 96 ± 1 vs 85 ± 9 cm, P = .045).

CONCLUSIONS

Two months of treatment with evolocumab 140 mg may improve endothelial function in subjects with increased cardiovascular risk. The improvement in endothelial function is proportional to LDL reduction.

LDL-apheresis in Acute Anterior Ischemic Optic Neuropathy

Acute anterior ischemic optic neuropathy (AION) is a disabling disease which impairs visual function. Standard treatment is unable to affect the outcome and the visual damage persists. We describe the case of a 64-year-old patient affected by AION, whose only known risk factor was hypercholesterolemia. After a first onset of involvement of the right eye (RE), the patient presented four weeks later with an analogous episode affecting the left eye (LE). Since standard treatment, started at involvement of the RE, had not yielded any beneficial effect, the patient underwent three sessions of LDL apheresis. The scotomatous portion of the visual field reduced even after the first session, there was further improvement after the third, and after six months the condition remained stable. Corrected vision improved from 2/10 to 6/10 after the third session. LDL cholesterol and fibrinogen decresade after the third session from 239 mg/dL to 31 mg/dL and from 289 mg/dL to 92 mg/dL, respectively. In conclusion, thanks to its effect of antagonizing hemorheologic disorders of the ocular microcirculation, LDL apheresis seems to be an efficacious treatment of AION, especially in patients suffering from hypercholesterolemia.

Evaluation of intermediate coronary stenoses in acute coronary syndromes using pressure guidewire

Fractional flow reserve (FFR) is increasingly used to guide myocardial revascularisation. However, supporting evidence regarding its use originates from studies that have enrolled mainly patients with stable angina, while patients with acute coronary syndromes (ACS) have not been included. Notably, multifactorial microvascular dysfunction and an increased sympathetic tone in patients with ACS may lead to blunted response to adenosine and false-negative results of FFR due to submaximal hyperaemia. This may raise the possibility of deferring treatment of stenosis that instead would have needed dilatation, thus leaving a residual risk of preventable cardiac events. In this literature review, we aim at summarising laboratory and clinical investigations concerning the use of FFR in culprit and non-culprit lesions in ACS. Furthermore, we will report recent data on instantaneous wave-free ratio, an adenosine-free index of functional stenosis severity, in stable coronary artery disease and in patients with ACS.

Preventive effect of pravastatin on the development of hypertension in patients with hypercholesterolemia: A post-hoc analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study

BACKGROUND

It remains unclear whether treatment of dyslipidemia with 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) reduces the risk of developing hypertension.

OBJECTIVE

In this post-hoc analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, a large-scale primary prevention trial with pravastatin, we examined the preventive effect of pravastatin on the future development of hypertension in patients with hypercholesterolemia.

METHODS

Of the overall (MEGA) Study population, 3397 nonhypertensive patients at baseline were enrolled in this study. The patients were randomly assigned to either the diet alone group (n = 1722) or the diet plus pravastatin group (n = 1675) and then were followed-up for a median of 36 months to determine new-onset hypertension.

RESULTS

During the follow-up period, 1595 patients developed hypertension (49.1% in the diet alone group and 44.7% in the diet plus pravastatin group). After adjusting for multiple covariates, the diet plus pravastatin group showed a 10% reduction in the risk of developing hypertension (hazard ratio 0.90, 95% confidence interval 0.81-0.998), compared with the diet alone group. Subgroup analyses revealed that the preventive effect of pravastatin on the development of hypertension was pronounced in patients aged ≥60 years, men, those with chronic kidney disease or diabetes mellitus and those without obesity.

CONCLUSIONS

Pravastatin reduced the risk of developing hypertension in Japanese patients with hypercholesterolemia. The risk reduction of cardiovascular disease with statins could be partly explained by their preventive effect on the development of hypertension.

The role of inorganic nitrate and nitrite in CVD

CVD is the leading cause of death worldwide, a consequence of mostly poor lifestyle and dietary behaviours. Although whole fruit and vegetable consumption has been consistently shown to reduce CVD risk, the exact protective constituents of these foods are yet to be clearly identified. A recent and biologically plausible hypothesis supporting the cardioprotective effects of vegetables has been linked to their inorganic nitrate content. Approximately 60–80 % inorganic nitrate exposure in the human diet is contributed by vegetable consumption. Although inorganic nitrate is a relatively stable molecule, under specific conditions it can be metabolised in the body to produce NO via the newly discovered nitrate–nitrite–NO pathway. NO is a major signalling molecule in the human body, and has a key role in maintaining vascular tone, smooth muscle cell proliferation, platelet activity and inflammation. Currently, there is accumulating evidence demonstrating that inorganic nitrate can lead to lower blood pressure and improved vascular compliance in humans. The aim of this review is to present an informative, balanced and critical review of the current evidence investigating the role of inorganic nitrate and nitrite in the development, prevention and/or treatment of CVD. Although there is evidence supporting short-term inorganic nitrate intakes for reduced blood pressure, there is a severe lack of research examining the role of long-term nitrate intakes in the treatment and/or prevention of hard CVD outcomes, such as myocardial infarction and cardiovascular mortality. Epidemiological evidence is needed in this field to justify continued research efforts.

Impaired blood rheology is associated with endothelial dysfunction in patients with coronary risk factors

To investigate the relationship between blood rheology and endothelial function in patients with coronary risk factors, brachial arterial flow-mediated vasodilatation (FMD), an index of endothelial function and blood passage time (BPT), an index of blood rheology, and fasting blood cell count, glucose metabolism, and plasma fibrinogen, lipid, C-reactive protein, and whole blood viscosity levels were measured in 95 patients with coronary risk factors and 37 healthy controls. Brachial arterial FMD after reactive hyperemia was assessed by ultrasonography. BPT was assessed using the microchannel method. In healthy controls, BPT significantly correlated with FMD (r = - 0.325, p <  0.05), HDL cholesterol (r = - 0.393, p <  0.05), body mass index (BMI; r = 0.530, p <  0.01), and plasma fibrinogen concentration (r = 0.335, p <  0.05). In a multivariate regression analysis adjusted for all clinical variables, BPT remained significantly associated with BMI and fibrinogen, but not with FMD, in healthy controls. In patients with coronary risk factors, BPT significantly correlated with FMD (r = - 0.331, p <  0.01), HDL cholesterol (r = - 0.241, p <  0.05), BMI (r = 0.290, p <  0.01), hematocrit (r = 0.422, p <  0.001), white blood cell count (r = 0.295, p <  0.01), platelet count (r = 0.204, p <  0.05), and insulin (r = 0.210, p <  0.05). In a multivariate regression analysis adjusted for all clinical variables, BPT remained strongly associated with FMD and hematocrit in patients with coronary risk factors. These data indicate that BPT is closely associated with FMD in patients with coronary risk factors and suggest that the measurement of blood rheology using the microchannel method may be useful in evaluating brachial arterial endothelial function as a marker of atherosclerosis in these patients.

Contribution of Plasma Lipid Disturbances to Vascular Endothelial Function in Patients With Slow Coronary Flow

Previous studies have suggested that microcirculatory abnormalities cause slow coronary flow (SCF). However, the underlying mechanism of this phenomenon has not yet been well documented. Therefore, the aim of this study was to determine the role of plasma lipid disturbances in pathogenesis of slow coronary flow (SCF). Forty patients with SCF (group I) and 37 subjects with normal coronary arteries (group II) were included in the study. In each subject plasma lipid concentrations (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglyceride [TG]) and brachial artery flow-mediated dilatation (FMD) and nitroglycerin (NTG)-induced dilatation were measured. Total cholesterol level was found to be similar in the 2 groups. In group I, HDL-C level was lower than in group II (34 ±3 vs 40 ±4 mg/dL, p=0.0001). In group I, TG level was higher than in group II (213 ±29 vs 198 ±24 mg/dL p=0.002). In group I, FMD was smaller than that of group II (3.48 ±3.1% vs 10.4 ±5.6%, p=0.0001). The percent NTG-induced dilatation was not different between the groups (15.5 ±5.3% vs 17.3 ±6.9%, p=0.27). On regression analysis; there was a significant relationship between percent of FMD and HDL-C ( r =0.65, p=0.0001). When the 2 groups were analyzed separately, HDL-C was still related to percent of FMD in both groups ( r =0.47 p=0.002 and r =0.45 p=0.005, respectively). Multivariate regression analysis showed that only plasma HDL-C was independently related to FMD (F=7.5 p=0.0001). In patients with SCF, reduced flow-mediated dilatation was detected and was found to be associated with plasma lipid disturbances, principally low HDL and high TG levels.

Effect of ascorbic acid on forearm reactive hyperaemia in patients with hypercholesterolaemia

BACKGROUND

This study was designed to research the effect of hypercholesterolaemia and ascorbic acid on forearm blood flow (FBF) reactive hyperaemia (RH). Reactive hyperaemia seems to be at least partly endothelium-dependent. Endothelial dysfunction has been described in patients with hypercholesterolaemia, and has been reversed with ascorbic acid administration.

METHOD

Forearm blood flow was studied with venous occlusion plethsmography in 26 healthy volunteers and 46 hypercholesterolaemic patients. Hypercholesterolaemic patients were divided into two groups. Group A comprised 25 patients, who received ascorbic acid and group B comprised 21 patients, who received placebo. All subjects underwent measurement of FBF at baseline and during RH (phase A). Forearm blood flow during RH was measured every 15 seconds for three minutes. Subsequently patients in group A received 2 g of ascorbic acid orally in the form of effervescent tablets, and patients in group B received placebo orally in the same form. Forearm blood flow measurements at baseline and during RH were repeated two hours later (phase B).

RESULTS

Maximal percent increase of FBF was significantly higher in healthy subjects than in hypercholesterolaemic patients (139.1+/-12.1% versus 73.1+/-11.0% respectively, P<0.05). Duration of RH was smaller in hypercholesterolaemic patients compared to normal subjects (60.9+/-17.1 seconds versus 105.6+/-10.2 seconds, P<0.05). Administration of ascorbic acid but not of placebo increased the duration of RH (69.1+/-11.1 seconds versus 104.1+/-12.2 seconds, P<0.05) but not of peak RH FBF.

CONCLUSION

Hypercholesterolaemia seems to impair both the early and late phase of RH. Ascorbic acid improves only the duration of RH, possibly due to its antioxidant effect on endothelium.

Cholesterol Enrichment Impairs Capacitative Calcium Entry, eNOS Phosphorylation & Shear Stress-Induced NO Production

Endothelial dysfunction, characterized by decreased production or availability of nitric oxide (NO), is widely believed to be the hallmark of early-stage atherosclerosis. In addition, hypercholesterolemia is considered a major risk factor for development of atherosclerosis and is associated with impaired flow-induced dilation. However, the mechanism by which elevated cholesterol levels leads to decreased production of NO is unclear. NO is released in response to shear stress and agonist-evoked changes in intracellular calcium. Although calcium signaling is complex, we have previously shown that NO production by endothelial nitric oxide synthase (eNOS) is preferentially activated by calcium influx via store-operated channels. We hypothesized that cholesterol enrichment altered this signaling pathway (known as capacitive calcium entry; CCE) ultimately leading to decreased NO. Our results show that cholesterol enrichment abolished ATP-induced eNOS phosphorylation and attenuated the calcium response by the preferential inhibition of CCE. Furthermore, cholesterol enrichment also inhibited shear stress-induced NO production and eNOS phosporylation, consistent with our previous results showing a significant role for ATP autocrine stimulation and subsequent activation of CCE in the endothelial flow response.

Do Statins Lower Blood Pressure?

Hypercholesterolemia is present in many patients with hypertension and adds a significant component of cardiovascular risk. The 3-hydroxy-3 methyl-glutarylcoenzyme A reductase inhibitors (statins) lower low-density lipoprotein cholesterol but also inhibit many of the structural and functional components of the arteriosclerotic process. Structural effects include reductions in vascular smooth muscle hypertrophy and proliferation, fibrin deposition, and collagen cross-linking. Among the functional effects are improvements in endothelial function, reduction in inflammatory cytokines and reactive oxygen species, and down-regulation of angiotensin II and endothelin receptors. These would be expected to reduce blood pressure in patients with hypertension; 14 studies have shown statin-induced decrease in blood pressure, but 11 studies showed no effect. Many of the studies had no placebo controls, were of short duration, or had small sample sizes, or combinations of these. Despite predictions made on the basis of the vasoprotective actions of statins, the blood-pressure-lowering effects of statins are at best modest.

Dyslipidemia and the Risk of Developing Hypertension in a Working-Age Male Population

BACKGROUND

Hypertension is one of the main comorbidities associated with dyslipidemia. This study aimed to examine the extent to which dyslipidemia increases the risk of developing hypertension in a Japanese working-age male population.

METHODS AND RESULTS

We analyzed data from 14 215 nonhypertensive male workers (age 38±9 years) who underwent annual medical checkups. Subjects were followed up for a median of 4 years to determine new-onset hypertension, defined as blood pressure (BP) ≥140/90 mm Hg or use of antihypertensive medication. The associations between serum lipid levels and development of hypertension were examined. During the follow-up period, 1483 subjects developed hypertension. After adjusting for age, body mass index, impaired fasting glucose/diabetes, baseline BP category, alcohol intake, smoking, exercise, and parental history of hypertension, subjects with a total cholesterol (TC) level ≥222 mg/dL were at a significantly increased risk of developing hypertension (hazard ratio: 1.28; 95% CI: 1.06-1.56) compared to subjects with a TC level ≤167 mg/dL. Similar results were observed for subjects with high low-density lipoprotein cholesterol (LDLC) and non-high-density lipoprotein cholesterol (HDLC) levels. A U-shaped relationship was found between HDLC level and risk of hypertension; compared to the third quintile, the multiadjusted hazard ratio was 1.22 (95% CI: 1.03-1.43) in the lowest quintile and 1.34 (95% CI: 1.12-1.60) in the highest quintile.

CONCLUSIONS

Elevated serum levels of TC, LDLC, and non-HDLC were associated with an increased risk of hypertension in working-age Japanese men. For HDLC, risk of hypertension was increased at both low and high levels.

Effect of protein arginine methyltransferase-1 inhibition on hypoxia-induced vasoconstriction

Hypoxia is defined as a decrease in the oxygen supply to a level below physiological levels which is insufficient to maintain cellular function, in the presence of unrestricted coronary inflow. It is one of the leading causes of global mortality and morbidity, due to its association with the pathology of cancer, cardiovascular disease and stroke. The common feature in these pathologies is the limitation of oxygen availability that participates in the development of these conditions. The pulmonary response to hypoxia, when hypoxia is localized, is hypoxic pulmonary vasoconstriction (HPV). HPV is a physiological and self-regulatory mechanism by which pulmonary capillary blood flow is automatically adjusted to alveolar ventilation for maintaining the optimal balance of ventilation and perfusion. In pathological conditions, HPV occurs as an acute episode during progressive critical illness or as a sustained response with vascular remodeling and pulmonary hypertension. Inspite of the hypoxia-induced shift in the redox status to a more oxidized state, the endothelium-dependent mediators of HPV that cause vasoconstrictor response to hypoxia include nitric oxide (NO), endothelin-1 and angiotensin-II. Indeed, in chronic hypoxia, due to the enhanced reactive oxygen species (ROS) generation, inhibition of endothelial nitric oxide synthase (eNOS) activity and reduced nitric oxide (NO) production there is an imbalance in the vasoconstriction-vasodilation status toward constriction. It is our hypothesis that, in hypoxic stress, a key player in initiating this imbalance is the enzyme, protein arginine methyltransferase-1 (PRMT1) which indirectly affects eNOS activity by increased production of asymmetric dimethylarginine (ADMA), a NOS-inhibitor. Thus, pharmacological inhibition of PRMT1 should restore the cellular and vascular homeostasis in hypoxic conditions.

Forearm vasodilator reactivity in healthy male carriers of the 3q22.3 rs9818870 polymorphism

BACKGROUND

A genome wide association study has identified a robust risk locus for cardiovascular disease on 3q22.3. However, the mechanisms by which the [C]/[T] polymorphism rs9818870 increases cardiovascular risk are unknown. This forearm blood flow (FBF) study addressed the question if the genetic association with cardiovascular disease in patients is preceded by incipient vasodilator impairment in young, healthy carriers of this new risk locus on chromosome 3.

MATERIALS AND METHODS

After a pre-screening of 74 subjects 17 male healthy volunteers homozygous/heterozygous for a single nucleotide polymorphism (SNP) risk allele on 3q22.3 and a control group of 17 healthy volunteers not carrying the allele were included into this case-control study.

RESULTS

Forearm vascular endothelium-dependent and -independent vasodilator responses were in the normal range in both groups, although endothelium-dependent FBF reactivity to acetylcholine was significantly higher in SNP carriers of the risk allele.

CONCLUSION

The augmented endothelium-dependent vasodilation of the forearm resistance vasculature does not support the presence of endothelial dysfunction in young SNP carriers and indicates that other mechanisms are responsible for the strong association between coronary artery diseases and the rs9818870 polymorphism, located on 3q22.3.

Influence of habitual high dietary fat intake on endothelium-dependent vasodilation

High-fat diets are associated with an increased risk of cardiovascular disease. A potential underlying mechanism for the increased cardiovascular risk is endothelial dysfunction. Nitric oxide (NO)-mediated endothelium-dependent vasodilation is critical in the regulation of vascular tone and overall vascular health. The aim of this study was to determine the influence of dietary fat intake on endothelium-dependent vasodilation. Forty-four middle-aged and older sedentary, healthy adults were studied: 24 consumed a lower fat diet (LFD; 29% ± 1% calories from fat) and 20 consumed a high-fat diet (HFD; 41% ± 1% calories from fat). Four-day diet records were used to assess fat intake, and classifications were based on American Heart Association guidelines (<35% of total calories from fat). Forearm blood flow (FBF) responses to acetylcholine, in the absence and presence of the endothelial NO synthase inhibitor N(G)-monomethyl-l-arginine (L-NMMA), as well as responses to sodium nitroprusside were determined by plethysmography. The FBF response to acetylcholine was lower (∼15%; P < 0.05) in the HFD group (4.5 ± 0.2 to 12.1 ± 0.8 mL/100 mL tissue/min) than in the LFD group (4.6 ± 0.2 to 14.4 ± 0.6 mL/100 mL tissue/min). L-NMMA significantly reduced the FBF response to acetylcholine in the LFD group (∼25%) but not in the HFD group. There were no differences between groups in the vasodilator response to sodium nitroprusside. These data indicate that a high-fat diet is associated with endothelium-dependent vasodilator dysfunction due, in part, to diminished NO bioavailability. Impaired NO-mediated endothelium-dependent vasodilation may contribute to the increased cardiovascular risk with high dietary fat intake.

PPARγ activation does not affect endothelin activity in non-diabetic patients with hypertension or hypercholesterolemia

OBJECTIVES

This study tested the hypothesis that pioglitazone reduces endothelin-1 activity in the forearm vasculature in non-diabetic patients with hypertension or hypercholesterolemia and variable degrees of insulin resistance.

METHODS

We conducted a single center, randomized, double-blind, placebo controlled, cross-over trial in 80 patients with either hypertension or hypercholesterolemia and further classified as insulin-sensitive or insulin-resistant based on a published insulin sensitivity index. Participants received pioglitazone 45 mg daily or matching placebo for eight weeks. The main endpoint was the change in forearm vascular endothelin-1 activity, as assessed by intra-arterial infusion of the endothelin type A receptor blocker BQ-123, measured at the end of each 8-week treatment period.

RESULTS

Pioglitazone lowered plasma insulin (P < 0.001), improved insulin sensitivity (P < 0.001), increased HDL (P < 0.001), and reduced triglycerides (P = 0.003), free fatty acids (P = 0.005), and C-reactive protein (P = 0.001). However, pioglitazone did not affect the vasodilator response to BQ-123 in the whole group (P = 0.618) and in the diagnosis or insulin sensitivity subgroups. Hence, in non-diabetic patients with hypertension or hypercholesterolemia, PPARγ activation with pioglitazone does not affect endothelin-1 activity, despite enhancing insulin sensitivity and reducing plasma insulin and C-reactive protein levels.

CONCLUSIONS

In non-diabetic patients with hypertension or hypercholesterolemia, pioglitazone improves insulin sensitivity, lipid profile, and inflammation but does not affect endothelin activity. Our data suggest that the determinants of endothelin-1 vascular activity in vivo may differ and/or be more complex than those suggested by the results of previous in vitro studies.

Endothelial Dysfunction in Patients With Coronary Artery Disease

Background:

The use of flow-mediated dilation (FMD) as a surrogate indicator for the extent of coronary artery disease (CAD) remains largely unknown. We assessed FMD at the brachial artery in 89 consecutive patients undergoing coronary angiography.

Methods and Results:

Patients were classified in groups 0 to 3 according to the number of diseased vessels and the SYNTAX score was calculated. The FMD decreased significantly from groups 0 to 3 ( P < .001). There was a significant linear relation between SYNTAX score and FMD (corrected r2 = .64, P < .001). In multivariate analysis, a reduced FMD was the only significant independent predictor of the presence of CAD (odds ratio [OR] 1.78, P = .032) and of CAD severity (OR 1.85, P = .005).

Conclusion:

This study confirms that FMD is reduced in patients with CAD and that such reduction in FMD is related to the extent of the disease. Therefore, FMD at the brachial artery is likely to represent a reliable indicator of CAD burden.

Rho-kinase inhibition improves ischemic perfusion deficit in hyperlipidemic mice

Hyperlipidemia is a major cardiovascular risk factor associated with progressive cerebrovascular dysfunction and diminished collateral perfusion in stroke. Rho-associated kinase (ROCK) may be an important mediator of hyperlipidemic vascular dysfunction. We tested the efficacy of acute or chronic ROCK inhibition on the size of dynamic perfusion defect using laser speckle flowmetry in hyperlipidemic apolipoprotein E knockout mice fed on a high-fat diet for 8 weeks. Mice were studied at an age before the development of flow-limiting atherosclerotic stenoses in aorta and major cervical arteries. Focal ischemia was induced by distal middle cerebral artery occlusion (dMCAO) during optical imaging. The ROCK inhibitor fasudil (10 mg/kg) was administered either as a single dose 1 hour before ischemia onset, or daily for 4 weeks. Fasudil decreased both baseline arterial blood pressure and cerebrovascular resistance (CVR) by ∼15%, and significantly improved tissue perfusion during dMCAO. Interestingly, peri-infarct depolarizations were also reduced. Chronic treatment did not further enhance these benefits compared with acute treatment with a single dose. These data show that ROCK inhibition improves CVR and ischemic tissue perfusion in hyperlipidemic mice.

Exercise training and vascular cell phenotype in a swine model of familial hypercholesterolaemia: conduit arteries and veins

NEW FINDINGS

What is the central question of this study? Does endurance exercise training cause anti-atherogenic effects on the endothelium in a swine model of familial hypercholesterolaemia (FH), and how are these effects distributed across veins, arteries and multiple vascular territories within each system? What is the main finding and its importance? Coronary artery endothelium-dependent vasomotor function was depressed in sedentary FH pigs compared with sedentary control animals, and exercise training did not change vasomotor function within FH. In systemic conduit arteries and veins, few effects of FH on endothelial cell protein expression were noted, including both pro- and anti-atherogenic changes. These findings suggest that exercise training does not produce a consistently improved endothelial cell phenotype in either coronary or systemic conduit vessels in this swine model of FH. Exercise training has emerged as an intervention for the primary and secondary prevention of coronary artery disease, but the mechanisms through which training reduces relative risk are not completely understood. The goal of this study was to investigate the impact of endurance exercise training on vasomotor function and vascular cell phenotype in coronary arteries and systemic conduit arteries and veins against a background of advanced atherosclerosis. We tested the hypothesis that exercise training restores endothelial vasomotor function and produces an anti-atherogenic endothelial and smooth muscle cell phenotype in familial hypercholesterolaemic (FH) swine. The study included 30 FH (15 exercised and 15 sedentary) and 13 non-FH control male castrated swine. The exercise-training intervention consisted of treadmill running 5 days per week for 16-20 weeks. Tissues sampled at sacrifice included vascular rings from the coronary circulation for vasomotor function experiments (dose-dependent bradykinin-induced vasorelaxation) and endothelial cells (ECs) from isolated segments of the thoracic aorta, the carotid, brachial, femoral and renal arteries, as well as each corresponding regionally associated vein, and from the abdominal vena cava, the right coronary and internal mammary arteries. Smooth muscle cells were sampled from the right coronary artery only. Vascular cell phenotype was assessed by immunoblotting for a host of both pro- and anti-atherogenic markers [e.g. endothelial nitric oxide synthase, p67phox, superoxide dismutase 1 (SOD1)]. Coronary artery endothelium-dependent vasomotor function was depressed in sedentary FH pigs compared with sedentary control pigs, and exercise training did not change vasomotor function within FH. In contrast, only scattered effects of FH on EC phenotype were noted across the vasculature, which included both pro- and anti-atherogenic changes in EC protein expression (e.g. increased endothelial nitric oxide synthase in carotid artery ECs, decreased p67phox in brachial artery ECs, but decreased expression of the antioxidant protein SOD1 in thoracic vena cava; all P < 0.05). In thoracic vena cava ECs, this deficit was corrected by exercise training, while no other effects of exercise were observed in conduit vessel EC phenotype. Thus, while exercise training abrogated the adverse effect of hypercholesterolaemia on thoracic vena cava SOD1 expression, it appears that exercise training does not produce a consistently improved EC phenotype in either coronary or systemic conduit vessels in this FH swine model.

Endothelial dysfunction over the course of coronary artery disease

The vascular endothelium regulates blood flow in response to physiological needs. Endothelial dysfunction is closely related to atherosclerosis and its risk factors, and it constitutes an intermediate step on the progression to adverse events throughout the natural history of coronary artery disease (CAD), often affecting clinical outcomes. Understanding the relation of endothelial function with CAD provides an important pathophysiological insight, which can be useful both in clinical and research management. In this review, we summarize the current knowledge on endothelial dysfunction and its prognostic influence throughout the natural history of CAD, from early atherosclerosis to post-transplant management.

Randomized controlled trial assessing the effect of simvastatin in primary biliary cirrhosis

BACKGROUND

This study evaluated the effect of statins in Primary biliary cirrhosis (PBC) on endothelial function, anti-oxidant status and vascular compliance.

METHODS

Primary biliary cirrhosis patients with hypercholesterolaemia were randomized to receive 20 mg simvastatin or placebo in a single blind, randomized controlled trial. Body mass index, blood pressure, glucose, liver function, lipid profile, immunoglobulin levels, serological markers of endothelial function and anti-oxidant status were measured as well as vascular compliance, calculated from pulse wave analysis and velocity, at recruitment and again at 3, 6, 9 and 12 months.

RESULTS

Twenty-one PBC patients (F = 20, mean age = 55) were randomized to simvastatin 20 mg (n = 11) or matched placebo (n = 10). At completion of the trial, serum cholesterol levels in the simvastatin group were significantly lower compared with the placebo group (4.91 mmol/L vs. 6.15 mmol/L, P = 0.01). Low-density lipoprotein (LDL) levels after 12 months were also significantly lower in the simvastatin group (2.33 mmol/L vs. 3.53 mmol/L, P = 0.01). After 12 months of treatment, lipid hydroperoxides were lower (0.49 μmol/L vs. 0.59 μmol/L, P = 0.10) while vitamin C levels were higher (80.54 μmol/L vs. 77.40 μmol/L, P = 0.95) in the simvastatin group. Pulse wave velocity remained similar between treatment groups at 12 months (8.45 m/s vs. 8.80 m/s, P = 0.66). Only one patient discontinued medication owing to side effects. No deterioration in liver transaminases was noted in the simvastatin group.

CONCLUSIONS

Statin therapy in patients with PBC appears safe and effective towards overall reductions in total cholesterol and LDL levels. Our initial study suggests that simvastatin may also confer advantageous effects on endothelial function and antioxidant status.