Multimarker approach to evaluate correlates of vascular stiffness: the Framingham Heart Study

COMPARING STAGES OF DIABETIC RETINOPATHY WITH SYSTEMIC VASCULAR STATUS USING FINGER PHOTOPLETHYSMOGRAPHY

PURPOSE

To evaluate systemic vascular fitness measured by finger photoplethysmography in diabetic retinopathy (DR).

METHODS

This was a cross-sectional observational study on patients with Type II diabetes mellitus from October 2020 to May 2021. Data collected include systolic/diastolic blood pressure, visual acuity, glycated hemoglobin, and central macular thickness. Diabetic retinopathy severity was categorized using the Early Treatment Diabetic Retinopathy Study classification. Photoplethysmography signals were acquired using pulse-oximeter modules (OEM-60; Dolphin Medical, Inc) measured for 90 seconds at 275 Hz sampling rate and 16-bit resolution, which records photoplethysmography fitness index, vascular risk prediction index, and vascular age.

RESULTS

One hundred and forty-one patients were equally distributed into six DR categories. Mean age was 58.8 ± 9.9 years, with female-to-male ratio of 1.27. There were significant differences in mean systolic (125.5 ± 10.0 mmHg, P = 0.007) and diastolic blood pressure (80.0 ± 8.8 mmHg), mean glycated hemoglobin (7.6 ± 1.9%, P = 0.005), median log unit of minimal angle of resolution (0.3, interquartile range: 0.2-0.5, P < 0.001), and central macular thickness ( P = 0.003) across DR severity. Significant differences were also seen in photoplethysmography fitness index ( P = 0.001), vascular risk prediction index ( P < 0.001), and vascular age ( P = 0.001), with poorer values in severe compared with mild/moderate DR. After adjusting for age, blood pressure, and glycated hemoglobin, photoplethysmography fitness reduces by 3.3% (regression coefficient, b = -3.27, P < 0.001), vascular age increases by 2.5 years ( b = 2.54, P = 0.002), and vascular risk prediction index increases by 3.1 ( b = 3.08, P < 0.001) with every DR worsening.

CONCLUSION

More severe DR stages were associated with poorer photoplethysmography vascular markers.

Characterizing the Origins of Primary Aldosteronism

BACKGROUND

Renin-independent aldosterone production in normotensive people increases risk for developing hypertension. In parallel, normotensive adrenal glands frequently harbor aldosterone-producing micronodules with pathogenic somatic mutations known to induce primary aldosteronism (PA). A deeper understanding of these phenomena would inform the origins of PA and its role in hypertension pathogenesis.

METHODS

Prospectively recruited normotensives underwent detailed characterization of PA features via the following: oral sodium suppression test to evaluate renin-independent aldosterone production, dexamethasone suppression and adrenocorticotropic hormone-stimulation tests to evaluate adrenocorticotropic hormone-mediated aldosterone production, and 24-hour ambulatory blood pressure monitoring. The magnitude of renin-independent aldosterone production was defined via tertiles of 24-hour urinary aldosterone production during the oral sodium suppression test to create unbiased categorizations of the magnitude of PA. Serum aldosterone, serum 18-hybrid steroids, urine tetrahydroaldosterone (biomarkers of aldosterone synthase activity), urinary potassium, and blood pressure (biomarkers of mineralocorticoid receptor activation) were evaluated across tertiles.

RESULTS

There was a spectrum of autonomous, nonsuppressible, and renin-independent production of aldosterone, 18-hybrid steroids, and 24-hour urinary tetrahydroaldosterone (P-trend <0.01). Correspondingly, there was a continuum of adrenocorticotropic hormone-mediated aldosterone production and 18-hybrid steroid production that also paralleled renin-independent aldosterone production. The spectrum of PA pathophysiology was associated with higher ambulatory daytime systolic BP (P-trend <0.05), even within the normotensive range, and greater urinary potassium excretion (P-trend <0.05), indicating a continuum of mineralocorticoid receptor activation.

CONCLUSIONS

The pathophysiologic continuum of PA, characterized by renin-independent and adrenocorticotropic hormone-mediated aldosterone production, and enhanced aldosterone synthase and mineralocorticoid receptor activity, is evident in normotensive people. These findings provide mechanistic explanations to implicate PA in the pathogenesis of a substantial proportion of hypertension.

Relationship Between Renin, Aldosterone, Aldosterone-to-Renin Ratio and Arterial Stiffness and Left Ventricular Mass Index in Young Adults

BACKGROUND

Primary aldosteronism, characterized by renin-independent aldosterone production, is associated with adverse cardiovascular remodeling and outcomes. Elevated cardiovascular risk is observed even in subclinical forms of primary aldosteronism according to studies conducted primarily in middle-aged and elderly populations. This study aimed to assess whether early changes in primary aldosteronism biomarkers during young adulthood are associated with arterial stiffness and left ventricular mass index (LVMI) before the onset of overt disease.

METHODS

The Raine Study is a longitudinal, population-based cohort study in Western Australia that enrolled women during pregnancy. We analyzed the data from the offspring of these women at 17 (2006-2009) and 27 (2016-2018) years of age. Participants with elevated high-sensitivity C-reactive protein (>10 mg/L) and female participants who were on oral contraception were excluded. Pulse wave velocity and aortic augmentation index were measured by SphygmoCor Pulse Wave System at both ages, and aortic distensibility and LVMI were measured by cardiac magnetic resonance imaging at 27 years. Multivariable linear regression was used to examine the relationship between plasma renin, aldosterone, or aldosterone-to-renin ratio and arterial stiffness and LVMI. Mediation analysis was used to test the role of systolic blood pressure.

RESULTS

This study included 859 participants at 17 (38.0% female) and 758 participants at 27 (33.2% female) years of age. Females had lower renin concentration at both 17 (20.7 mU/L versus 25.7 mU/L; P<0.001) and 27 (12.0 mU/L versus 15.4 mU/L; P<0.001) years of age; hence, the aldosterone-to-renin ratio was significantly higher at both 17 (18.2 versus 13.5; P<0.001) and 27 (21.0 versus 15.6; P<0.001) years of age in females compared with males. At 27 years of age, a significant association was detected between aldosterone and LVMI in males (β=0.009 [95% CI, 0.001-0.017]; P=0.027) and between aldosterone-to-renin ratio and LVMI in females (β=0.098 [95% CI, 0.001-0.196]; P=0.050) independently of systolic blood pressure and other confounders. No association was found between primary aldosteronism biomarkers and measures of arterial stiffness (pulse wave velocity, aortic augmentation index, and aortic distensibility) at either age.

CONCLUSIONS

Aldosterone concentration and aldosterone-to-renin ratio were positively associated with the LVMI in young males and females, respectively, independently of systolic blood pressure. Long-term follow-up is required to determine whether the relationship persists over time, and clinical trials are needed to assess the cardiovascular benefits of early interventions to block aldosterone.

PAI-1 Regulates the Cytoskeleton and Intrinsic Stiffness of Vascular Smooth Muscle Cells

BACKGROUND

Plasma concentration of PAI-1 (plasminogen activator inhibitor-1) correlates with arterial stiffness. Vascular smooth muscle cells (SMCs) express PAI-1, and the intrinsic stiffness of SMCs is a major determinant of total arterial stiffness. We hypothesized that PAI-1 promotes SMC stiffness by regulating the cytoskeleton and that pharmacological inhibition of PAI-1 decreases SMC and aortic stiffness.

METHODS

PAI-039, a specific inhibitor of PAI-1, and small interfering RNA were used to inhibit PAI-1 expression in cultured human SMCs. Effects of PAI-1 inhibition on SMC stiffness, F-actin (filamentous actin) content, and cytoskeleton-modulating enzymes were assessed. WT (wild-type) and PAI-1-deficient murine SMCs were used to determine PAI-039 specificity. RNA sequencing was performed to determine the effects of PAI-039 on SMC gene expression. In vivo effects of PAI-039 were assessed by aortic pulse wave velocity.

RESULTS

PAI-039 significantly reduced intrinsic stiffness of human SMCs, which was accompanied by a significant decrease in cytoplasmic F-actin content. PAI-1 gene knockdown also decreased cytoplasmic F-actin. PAI-1 inhibition significantly increased the activity of cofilin, an F-actin depolymerase, in WT murine SMCs, but not in PAI-1-deficient SMCs. RNA-sequencing analysis suggested that PAI-039 upregulates AMPK (AMP-activated protein kinase) signaling in SMCs, which was confirmed by Western blotting. Inhibition of AMPK prevented activation of cofilin by PAI-039. In mice, PAI-039 significantly decreased aortic stiffness and tunica media F-actin content without altering the elastin or collagen content.

CONCLUSIONS

PAI-039 decreases intrinsic SMC stiffness and cytoplasmic stress fiber content. These effects are mediated by AMPK-dependent activation of cofilin. PAI-039 also decreases aortic stiffness in vivo. These findings suggest that PAI-1 is an important regulator of the SMC cytoskeleton and that pharmacological inhibition of PAI-1 has the potential to prevent and treat cardiovascular diseases involving arterial stiffening.

Should aortic stiffness parameters be used in MIS-C patient follow-up?

We evaluated the short- and long-term effects of multisystem inflammatory syndrome in children (MIS-C) on their cardiovascular system. The study population consisted of 38 MIS-C patients and 55 control patients. Standard echocardiographic measurements and aortic stiffness parameters were compared between the two groups at different time points. During the standard echocardiographic examination at the time of diagnosis, mitral valve insufficiency was detected in 42% of the cases, left ventricular systolic dysfunction in 36%, aortic valve insufficiency in 3%, tricuspid valve insufficiency in 13%, and coronary artery dilatation in 31%. The ejection fraction, pulse pressure of the experimental group were significantly lower than the control group (p < 0.01, p = 0.045, respectively). When aortic stiffness parameters were compared, it was seen that the parameters increased in the experimental group and the difference was significant for aortic distensibility. (p = 0.105, p = 0.029 respectively). When comparing the experimental group's results at diagnosis and at the sixth month, there was a decrease in aortic stiffness parameters at the sixth month compared to the time of diagnosis, but the difference wasn't significant (p = 0.514, p = 0.334). However, no statistically significant difference was detected when comparing the aortic distensibility results of the experimental group with the control group at the sixth month (p = 0.667). Our results showed that many pathological echocardiographic findings detected at diagnosis in MIS-C patients returned to normal within six months. Therefore, we believe that the cardiovascular follow-up period of MIS-C cases should be at least six months.

Past, Present, and Future Perspectives of Plasminogen Activator Inhibitor 1 (PAI-1)

Plasminogen activator inhibitor 1 (PAI-1), a SERPIN inhibitor, is primarily known for its regulation of fibrinolysis. However, it is now known that this inhibitor functions and contributes to many (patho)physiological processes including inflammation, wound healing, cell adhesion, and tumor progression.This review discusses the past, present, and future roles of PAI-1, with a particular focus on the discovery of this inhibitor in the 1970s and subsequent characterization in health and disease. Throughout the past few decades diverse functions of this serpin have unraveled and it is now considered an important player in many disease processes. PAI-1 is expressed by numerous cell types, including megakaryocytes and platelets, adipocytes, endothelial cells, hepatocytes, and smooth muscle cells. In the circulation PAI-1 exists in two pools, within plasma itself and in platelet α-granules. Platelet PAI-1 is secreted following activation with retention of the inhibitor on the activated platelet membrane. Furthermore, these anucleate cells contain PAI-1 messenger ribonucleic acid to allow de novo synthesis.Outside of the traditional role of PAI-1 in fibrinolysis, this serpin has also been identified to play important roles in metabolic syndrome, obesity, diabetes, and most recently, acute respiratory distress syndrome, including coronavirus disease 2019 disease. This review highlights the complexity of PAI-1 and the requirement to ascertain a better understanding on how this complex serpin functions in (patho)physiological processes.

Association of arterial stiffness with a prothrombotic state in uncomplicated nondiabetic hypertensive patients

Background and aims

Past studies reported a significant contribution of a prothrombotic state to the development and progression of target organ damage in hypertensive patients. Stiffening of arterial vessels is associated with aging and hypertension, and additional factors could contribute to this process. This study was designed to examine the relationships between arterial stiffening and the hemostatic and fibrinolytic system.

Methods

In 128 middle-aged, nondiabetic, essential hypertensive patients without major cardiovascular and renal complications, we measured coagulation markers that express the spontaneous activation of the hemostatic and fibrinolytic system and assessed stiffness of the arterial tree by measurement of the carotid/femoral pulse wave velocity (cfPWV) and pulse wave analysis with calculation of the brachial augmentation index (AIx).

Results

Levels of fibrinogen (FBG), D-dimer (D-d), and plasminogen activator-inhibitor 1 (PAI-1) were significantly higher in patients with PWV and AIx above the median of the distribution. FBG, D-d, and PAI-1 were significantly and directly related with both cfPWV and AIx, and multivariate regression analysis indicated that the relationships of D-d and PAI-1 with both cfPWV and AIx and of FBG with AIx, were independent of age, body mass index, severity and duration of hypertension, use of antihypertensive drugs, blood glucose, and plasma lipids.

Conclusion

In middle-aged, uncomplicated, nondiabetic patients with essential hypertension, spontaneous activation of plasma hemostatic cascade and impaired fibrinolysis is significantly and independently associated with stiffening of the arterial tree.

Relationship between the volume of perivascular adipose tissue and the vascular wall lesion

Aim. To study the relationship between the volume of perivascular adipose tissue (PVAT) and the vascular wall lesion.

Material and methods. The study included 318 patients without cardiovascular disease (mean age, 63,5±13,7 years). Hypertension was detected in 268 (84,3%) patients. All patients underwent assessment of anthropometric characteristics, lipid profile, arterial wall stiffness with the estimation of cardio-ankle vascular index, intima-media thickness, brachial artery endothelial vasomotor function. Chest computed tomography was performed with the estimation of the volumes of PVAT and pericardial adipose tissue (PAT).

Results. The volume of PVAT, on average, was 0,3 [0,2; 0,4] cm3 . The VAT volume was significantly higher in obese individuals when compared with patients with normal body weight: 0,4 [0,3; 0,5] vs 0,25 [0,2; 0,4] cm3 (p=0,0007). The VAT volume was higher in individuals with an increased CAVI level when compared with patients with normal CAVI values: 0,4 [0,3; 0,5] vs 0,3 [0,25; 0,3] (p=0,02). A significant correlation was found between the VAT volume and body mass index (r=0,27, p<0,005), waist circumference (r=0,41, p<0,005), CAVI (r=0,49, p<0,05), impaired endothelium-dependent brachial artery vasodilation (r=0,38, p<0,05). When performing multiple linear regression, a significant relationship of CAVI was found with age (β±SE, 0,51±0,15; p=0,002) and volume of PVAT (β±SE, 0,41±0,13; p=0,005).

Conclusion. The results indicate the relationship of PVAT with visceral obesity and vascular wall stiffness parameters.

Adipokines and Arterial Stiffness in Obesity

Adipokines are active molecules with pleiotropic effects produced by adipose tissue and involved in obesity-related metabolic and cardiovascular diseases. Arterial stiffness, which is a consequence of arteriosclerosis, has been shown to be an independent predictor of cardiovascular morbidity and mortality. The pathogenesis of arterial stiffness is complex but incompletely understood. Adipokines dysregulation may induce, by various mechanisms, vascular inflammation, endothelial dysfunction, and vascular remodeling, leading to increased arterial stiffness. This article summarizes literature data regarding adipokine-related pathogenetic mechanisms involved in the development of arterial stiffness, particularly in obesity, as well as the results of clinical and epidemiological studies which investigated the relationship between adipokines and arterial stiffness.

A Serpin With a Finger in Many PAIs: PAI-1's Central Function in Thromboinflammation and Cardiovascular Disease

Plasminogen activator inhibitor 1 (PAI-1) is a member of the serine protease inhibitor (serpin) superfamily. PAI-1 is the principal inhibitor of the plasminogen activators, tissue plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA). Turbulence in the levels of PAI-1 tilts the balance of the hemostatic system resulting in bleeding or thrombotic complications. Not surprisingly, there is strong evidence that documents the role of PAI-1 in cardiovascular disease. The more recent uncovering of the coalition between the hemostatic and inflammatory pathways has exposed a distinct role for PAI-1. The storm of proinflammatory cytokines liberated during inflammation, including IL-6 and TNF-α, directly influence PAI-1 synthesis and increase circulating levels of this serpin. Consequently, elevated levels of PAI-1 are commonplace during infection and are frequently associated with a hypofibrinolytic state and thrombotic complications. Elevated PAI-1 levels are also a feature of metabolic syndrome, which is defined by a cluster of abnormalities including obesity, type 2 diabetes, hypertension, and elevated triglyceride. Metabolic syndrome is in itself defined as a proinflammatory state associated with elevated levels of cytokines. In addition, insulin has a direct impact on PAI-1 synthesis bridging these pathways. This review describes the key physiological functions of PAI-1 and how these become perturbed during disease processes. We focus on the direct relationship between PAI-1 and inflammation and the repercussion in terms of an ensuing hypofibrinolytic state and thromboembolic complications. Collectively, these observations strengthen the utility of PAI-1 as a viable drug target for the treatment of various diseases.

Biological Pathways in Adolescent Aortic Stiffness

Background

Aortic stiffening begins in youth and antedates future hypertension. In adults, excess weight, systemic inflammation, dyslipidemia, insulin resistance, neurohormonal activation, and altered adipokines are implicated in the pathogenesis of increased aortic stiffness. In adolescents, we assessed the relations of comprehensive measures of aortic stiffness with body mass index (BMI) and related but distinct circulating biomarkers.

Methods and Results

A convenience sample of 246 adolescents (mean age, 16±2 years; 45% female, 24% Black, and 43% Hispanic) attending primary care or preventive cardiology clinics at 2 tertiary hospitals was grouped as normal weight (N=98) or excess weight (N=148, defined as BMI ≥age‐ and sex‐referenced 85th percentile). After an overnight fast, participants underwent anthropometry, noninvasive arterial tonometry, and assays for serum lipids, CRP (C‐reactive protein), glucose, insulin, renin, aldosterone, and leptin. We used multivariable linear regression to relate arterial stiffness markers (including carotid‐femoral pulse wave velocity) to BMI z score and a biomarker panel. Carotid‐femoral pulse wave velocity was higher in excess weight compared with normal weight group (5.0±0.7 versus 4.6±0.6 m/s; P<0.01). After multivariable adjustment, carotid‐femoral pulse wave velocity was associated with BMI z score (0.09 [95% CI, 0.01–0.18]; P=0.04) and with low‐density lipoprotein cholesterol (0.26 [95% CI, 0.03–0.50]; P=0.03).

Conclusions

Higher BMI and low‐density lipoprotein cholesterol were associated with greater aortic stiffness in adolescents. Maintaining optimal BMI and lipid levels may mitigate aortic stiffness.

Can the Absence of Hypertension Refine the Risk Assessment of Older Adults for Future Cardiovascular Events?

We sought to determine if the absence of hypertension in older adults can be used to identify those at lower risk of atherosclerotic cardiovascular disease (ASCVD). We identified participants ≥75 years old free of cardiovascular disease (CVD) in the National Institutes of Health Pooled Cohorts with and without hypertension. We assessed the association between systolic blood pressure (BP), diastolic BP, and cardiovascular events using multivariable modeling. The association between predicted ASCVD risk and observed events was compared. Of 2,667 adults aged ≥75 years, 67.9% had hypertension. Lower systolic BP correlated with lower CVD event rates. ASCVD predicted risk score and systolic BP were both independently associated with ASCVD event rates. Among adults with similar ASCVD predicted risk estimates, those without (vs with) hypertension had lower observed event rates across the predicted risk spectrum. The absence of hypertension may help refine the risk stratification of older adults, particularly those with intermediate predicted risk.

Modification of ventriculo-arterial coupling by spironolactone in nonischemic dilated cardiomyopathy

Aims

We sought to clarify the role of ventriculo–arterial (V–A) coupling in the treatment of nonischemic dilated cardiomyopathy (NIDCM) by adding a mineralocorticoid receptor antagonist (MRA) to conventional anti‐failure therapy.

Methods and results

We employed cardiac magnetic resonance imaging to quantify left ventricular (LV) contractility and V–A coupling in normal subjects at rest (n = 11) and in patients with NIDCM (n = 12) before and after long term anti‐failure therapy, in which MRA was added to conventional anti‐failure therapy. After ≥6 months' treatment in NIDCM patients, LV volumes and mass decreased, and the LV ejection fraction increased from a median of 24% (17, 27) (interquartile range IQR) to 47 (42, 52) (P < 0.002), with a marked reduction in arterial elastance (Ea) from 2.89 mmHg/mL (2.34, 4.0) to 1.50 (1.29, 1.95) (P < 0.002), similar to Ea of normal subjects, 1.53 (1.34, 1.67) (P > 0.05). The V–A coupling ratio, Ea/end‐systolic elastance (single‐beat method), decreased by −1.08 (−1.96, −0.55), (P = 0.003), as did Ea/end‐systolic pressure/end‐systolic pressure ratio, −0.54 (0.35, 0.87), (P = 0.002). The preload recruitable stroke work (PRSW) increased as did PRSW indexed for Ea (both P = 0.002), which reflected ‘total circulatory performance’.

Conclusions

In NIDCM, adding MRA to conventional anti‐failure therapy markedly improved LV ejection fraction and reduced peripheral vascular resistance, due to both improved LV contractility and especially to enhanced V–A coupling, as Ea decreased to normal. Total circulatory performance was a sensitive indicator of both LV pump performance and the arterial loading conditions.

Aldosterone-to-renin ratio is related to arterial stiffness when the screening criteria of primary aldosteronism are not met

Aldosterone-to-renin ratio (ARR) is a screening tool for primary aldosteronism (PA), but the significance of ARR when the PA criteria are not met remains largely unknown. In this cross-sectional study we investigated the association of ARR with haemodynamic variables in 545 normotensive and never-medicated hypertensive subjects (267 men, 278 women, age range 19-72 years) without suspicion of PA. Supine haemodynamic data was recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis. In sex-adjusted quartiles of ARR, determined as serum aldosterone to plasma renin activity ratio, the mean values were 282, 504, 744 and 1467 pmol/µg of angiotensin I/h, respectively. The only difference in haemodynamic variables between the ARR quartiles was higher pulse wave velocity (PWV) in the highest quartile versus other quartiles (p = 0.004), while no differences in blood pressure (BP), heart rate, wave reflections, cardiac output or systemic vascular resistance were observed between the quartiles. In linear regression analysis with stepwise elimination, ARR was an independent explanatory factor for PWV (β = 0.146, p < 0.001, R2 of the model 0.634). In conclusion, ARR was directly and independently associated with large arterial stiffness in individuals without clinical suspicion of PA. Therefore, ARR could serve as a clinical marker of cardiovascular risk.Trial registration: ClinicalTrails.gov: NCT01742702.

Plasminogen activator inhibitor-1 activity and the 4G/5G polymorphism are prospectively associated with blood pressure and hypertension status

OBJECTIVES

Plasminogen activator inhibitor-1 (PAI-1) has consistently shown positive associations with blood pressure (BP). Whether elevations in PAI-1 levels precede or result from raised BP is still under debate and data on prospective studies are limited. Hence, we investigated the prospective associations of PAI-1 and the 4G/5G polymorphism with brachial and central BP and pulse pressure (PP) over a 10-year period.

METHODS

Black South Africans aged 30 years and older were included. Baseline data collection commenced in 2005 (n = 2010) with follow-up data collection in 2010 (n = 1288) and 2015 (n = 926). Plasma PAI-1 activity (PAI-1act), 4G/5G polymorphism genotyping, waist circumference and BP measurements were performed and analysed using sequential regression and mixed models.

RESULTS

In multivariable adjusted analyses, PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension in the total group [1.04 (1.01; 1.08) and 1.82 (1.07; 3.12) respectively]. Furthermore, PAI-1act was prospectively associated with brachial SBP (r = 0.0815) and PP (r = 0.0832) in the total group, and with central PP in women (r = 0.1125; all P < 0.05). Addition of waist circumference to the models either decreased or nullified the contribution of PAI-1act to BP and hypertension development.

CONCLUSION

PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension. Furthermore, PAI-1act associated prospectively with both brachial and central BP. These associations were mediated in part by central adiposity. The study supports the hypothesis that PAI-1 also contributes to hypertension development rather than solely being a consequence thereof.

Triglyceride/HDL-cholesterol ratio and plasminogen activator inhibitor-1 independently predict high pulse pressure in sickle cell trait and disease

We hypothesised that TG/HDL-C ratio and PAI-1 would be associated with high pulse pressure (PP) in young adults with sickle cell trait (SCT) and sickle cell disease (SCD). We compared the clinical, biochemical, and cardiometabolic parameters among individuals with normal genotype (HbAA; n = 60), SCT (HbAS; n = 60), and SCD (HbSS; n = 60), all in steady state. Using multivariate linear regression analysis, high PP was positively related to TG/HDL-C ratio in SCT (β = 0.307; p = .014) and PAI-1 (β = 0.499; p = .001) in SCD. The curve of receiver operating characteristic also showed that TG/HDL-C ratio and PAI-1 are efficient predictors of high PP in SCT carriers and SCD patients, respectively. This study suggests that increased levels of TG/HDL-C ratio and PAI-1 may be salient risk factors that would promote the development of arterial stiffness and other CVD in SCT carriers and SCD patients.

Unbiased proteomics identifies plasminogen activator inhibitor-1 as a negative regulator of endothelial nitric oxide synthase

Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is a critical mediator of vascular function. eNOS is tightly regulated at various levels, including transcription, co- and posttranslational modifications, and by various protein-protein interactions. Using stable isotope labeling with amino acids in cell culture (SILAC) and mass spectrometry (MS), we identified several eNOS interactors, including the protein plasminogen activator inhibitor-1 (PAI-1). In cultured human umbilical vein endothelial cells (HUVECs), PAI-1 and eNOS colocalize and proximity ligation assays demonstrate a protein-protein interaction between PAI-1 and eNOS. Knockdown of PAI-1 or eNOS eliminates the proximity ligation assay (PLA) signal in endothelial cells. Overexpression of eNOS and HA-tagged PAI-1 in COS7 cells confirmed the colocalization observations in HUVECs. Furthermore, the source of intracellular PAI-1 interacting with eNOS was shown to be endocytosis derived. The interaction between PAI-1 and eNOS is a direct interaction as supported in experiments with purified proteins. Moreover, PAI-1 directly inhibits eNOS activity, reducing NO synthesis, and the knockdown or antagonism of PAI-1 increases NO bioavailability. Taken together, these findings place PAI-1 as a negative regulator of eNOS and disruptions in eNOS-PAI-1 binding promote increases in NO production and enhance vasodilation in vivo.

Memory impairment in spontaneously hypertensive rats is associated with hippocampal hypoperfusion and hippocampal vascular dysfunction

We investigated the effect of chronic hypertension on hippocampal arterioles (HippAs) and hippocampal perfusion as underlying mechanisms of memory impairment, and how large artery stiffness relates to HippA remodeling. Using male spontaneously hypertensive rats (SHR) and normotensive Wistar rats (n = 12/group), long-term (LTM) and spatial memory were tested using object recognition and spontaneous alternation tasks. Hippocampal blood flow was measured via hydrogen clearance basally and during hypercapnia. Reactivity of isolated and pressurized HippAs to pressure and pharmacological activators and inhibitors was investigated. To determine large artery stiffness, distensibility and elastin content were measured in thoracic aorta. SHR had impaired LTM and spatial memory associated with decreased basal blood flow (68 ± 12 mL/100 g/min) vs. Wistar (111 ± 28 mL/100 g/min, p < 0.01) that increased during hypercapnia similarly between groups. Compared to Wistar, HippAs from SHR had increased tone at 60 mmHg (58 ± 9% vs. 37 ± 7%, p < 0.01), and decreased reactivity to small- and intermediate-conductance calcium-activated potassium (SK/IK) channel activation. HippAs in both groups were unaffected by NOS inhibition. Decreased elastin content correlated with increased stiffness in aorta of SHR that was associated with increased stiffness and hypertrophic remodeling of HippAs. Hippocampal vascular dysfunction during hypertension could potentiate memory deficits and may provide a therapeutic target to limit vascular cognitive impairment.

Association of homocysteine with carotid-femoral pulse wave velocity in a southern Chinese population

This study aimed to investigate whether plasma homocysteine levels were associated with carotid-femoral pulse wave velocity (cfPWV), a golden standard of arterial stiffness, in a population from southern China. A cross-sectional study was conducted on 713 patients admitted to the First Affiliated Hospital of Fujian Medical University from February 2016 to August 2017. They were divided into four groups based on gender-specific quartile of homocysteine levels. Age, cfPWV, uric acid levels, and percentage of hypertension increased with ascending quartiles. The duration of hypertension and systolic blood pressure were higher in the highest quartile than in the lowest quartile. Pearson's correlation analysis and multivariate regression showed a correlation of homocysteine levels with cfPWV. A nearly twofold increased risk of cfPWV ≥10 m/s was observed in the highest quartile compared with the lowest quartile (in the highest quartile: odds ratio = 2.917, 95% confidence interval: 1.635-5.202, P < 0.001). After stratification, this correlation was present in both sexes, in patients aged over 65 years, and those with hypertension. The plasma homocysteine levels were independently associated with cfPWV in the population from southern China, especially in the elderly and those with hypertension.

Glycine supplementation extends lifespan of male and female mice

Diets low in methionine extend lifespan of rodents, though through unknown mechanisms. Glycine can mitigate methionine toxicity, and a small prior study has suggested that supplemental glycine could extend lifespan of Fischer 344 rats. We therefore evaluated the effects of an 8% glycine diet on lifespan and pathology of genetically heterogeneous mice in the context of the Interventions Testing Program. Elevated glycine led to a small (4%-6%) but statistically significant lifespan increase, as well as an increase in maximum lifespan, in both males (p = 0.002) and females (p < 0.001). Pooling across sex, glycine increased lifespan at each of the three independent sites, with significance at p = 0.01, 0.053, and 0.03, respectively. Glycine-supplemented females were lighter than controls, but there was no effect on weight in males. End-of-life necropsies suggested that glycine-treated mice were less likely than controls to die of pulmonary adenocarcinoma (p = 0.03). Of the 40 varieties of incidental pathology evaluated in these mice, none were increased to a significant degree by the glycine-supplemented diet. In parallel analyses of the same cohort, we found no benefits from TM5441 (an inhibitor of PAI-1, the primary inhibitor of tissue and urokinase plasminogen activators), inulin (a source of soluble fiber), or aspirin at either of two doses. Our glycine results strengthen the idea that modulation of dietary amino acid levels can increase healthy lifespan in mice, and provide a foundation for further investigation of dietary effects on aging and late-life diseases.

Cardiovascular protection in females linked to estrogen-dependent inhibition of arterial stiffening and macrophage MMP12

Arterial stiffening is a consequence of aging and a cholesterol-independent risk factor for cardiovascular disease (CVD). Arterial stiffening and CVD show a sex bias, with men more susceptible than premenopausal women. How arterial stiffness and sex interact at a molecular level to confer risk of CVD is not well understood. Here, we used the sexual dimorphism in LDLR-null mice to show that the protective effect of female sex on atherosclerosis is linked to reduced aortic stiffness and reduced expression of matrix metalloproteinase-12 (MMP12) by lesional macrophages. Deletion of MMP12 in LDLR-null mice attenuated the male sex bias for both arterial stiffness and atherosclerosis, and these effects occurred despite high serum cholesterol. Mechanistically, we found that oxidized LDL stimulates secretion of MMP12 in human as well as mouse macrophages. Estrogen antagonizes this effect by downregulating MMP12 expression. Our data support cholesterol-independent causal relationships between estrogen, oxidized LDL-induced secretion of macrophage MMP12, and arterial stiffness that protect against atherosclerosis in females and emphasize that reduced MMP12 functionality can confer atheroprotection to males.

Relationship between plasma plasminogen activator inhibitor-1 and hypertension in American Indians: findings from the Strong Heart Study

OBJECTIVES

Deficient plasminogen activator inhibitor-1 (PAI-1) prevented hypertension in mice. Plasma PAI-1 was associated with hypertension in cross-sectional analyses, but the prospective association of PAI-1 with incident hypertension in large epidemiological studies is scarce.

METHODS

Leveraging two longitudinal cohorts of American Indians in the Strong Heart Study (SHS, N = 1019) and the Strong Heart Family Study (SHFS, N = 1502), we examined the prospective association of plasma PAI-1 with incident hypertension by multivariate logistic regression, adjusting for age, sex, study site, smoking, drinking, dietary sodium, obesity, lipids, fasting glucose, kidney function, inflammation, and follow-up years. Family relatedness in the SHFS was accounted for using the GLIMMIX procedure. Plasma PAI-1 level at baseline was measured by immunoassay. All participants were free of hypertension, cardiovascular diseases, and chronic kidney disease at baseline.

RESULTS

A total of 305 and 258 participants, respectively, from the SHS (57 ± 7 years) and the SHFS (33 ± 13 years) developed incident hypertension during follow-up. In the SHS, higher level of log-transformed PAI-1 was associated with 1.35-fold increased risk of hypertension [odds ratio (OR) (95% confidence interval): 1.35 (1.06-1.72)]. Analysis using categorical PAI-1 (in tertiles) showed that participants in the highest tertile (≥58 ng/ml) had 63% increased risk for hypertension [OR = 1.63 (1.12-2.37)] compared with those in the lowest tertile (<33 ng/ml). This association was confirmed in the SHFS with similar effect sizes [OR = 1.41 (1.11-1.81) for log-transformed PAI-1; OR = 1.64 (1.08-2.50) for categorical PAI-1: ≥58 vs. <33 ng/ml].

CONCLUSION

A higher level of plasma PAI-1 is significantly associated with hypertension in American Indians, independent of established risk factors. The potential causality warrants further investigation.

Association between serum total homocysteine and arterial stiffness in adults: a community-based study

Both increased arterial stiffness and higher total homocysteine (tHcy) are associated with an elevated risk for cardiovascular disease. However, the relationship between tHcy and arterial stiffness is still inconclusive. The authors aimed to test the relationship of tHcy with carotid-femoral pulse wave velocity (cfPWV) and examine the possible effect modifiers in adults. A study was conducted from July to September 2016 in Jiangsu Province, China. A total of 16 644 participants were enrolled in the final analysis. Increased arterial stiffness is defined as a cfPWV ≥10 m/s. Overall, there was a positive association between tHcy and cfPWV levels (per 5-μmol/L tHcy increase: β = 0.10; 95% confidence interval [CI], 0.08-0.13) and increased arterial stiffness (per 5-μmol/L tHcy increase: odds ratio, 1.11; 95% CI, 1.07-1.14). Compared with participants with tHcy <10 μmol/L, the significantly higher cfPWV levels were observed in those with tHcy ≥15 μmol/L (β = 0.37; 95% CI, 0.28-0.47). Accordingly, a higher prevalence of increased arterial stiffness was found in patients with tHcy10 to <15 μmol/L (odds ratio, 1.18; 95% CI, 1.05-1.33) and tHcy ≥15 μmol/L (odds ratio, 1.50; 95% CI, 1.32-1.71) as compared with participants with tHcy <10 μmol/L. Furthermore, the stronger positive association was found in participants who were older (≥60 years, P for interaction = .008), had low body mass index (<25 kg/m² , P for interaction = .026), high systolic blood pressure levels (≥145 mm Hg [median], P for interaction = .048), or diabetes mellitus (P for interaction = .045). The present study demonstrated that serum tHcy concentrations were positively associated with cfPWV and the prevalence of increased arterial stiffness. These results suggest that the cardiovascular effects of tHcy may partly be mediated through arterial stiffness.

A null mutation in SERPINE1 protects against biological aging in humans

Plasminogen activator inhibitor-1 (PAI-1) has been shown to be a key component of the senescence-related secretome and a direct mediator of cellular senescence. In murine models of accelerated aging, genetic deficiency and targeted inhibition of PAI-1 protect against aging-like pathology and prolong life span. However, the role of PAI-1 in human longevity remains unclear. We hypothesized that a rare loss-of-function mutation in SERPINE1 (c.699_700dupTA), which encodes PAI-1, could play a role in longevity and metabolism in humans. We studied 177 members of the Berne Amish community, which included 43 carriers of the null SERPINE1 mutation. Heterozygosity was associated with significantly longer leukocyte telomere length, lower fasting insulin levels, and lower prevalence of diabetes mellitus. In the extended Amish kindred, carriers of the null SERPINE1 allele had a longer life span. Our study indicates a causal effect of PAI-1 on human longevity, which may be mediated by alterations in metabolism. Our findings demonstrate the utility of studying loss-of-function mutations in populations with geographic and genetic isolation and shed light on a novel therapeutic target for aging.

Relation between Arterial Stiffness and Markers of Inflammation and Hemostasis - Data from the Population-based Gutenberg Health Study

The relation between inflammation, hemostasis and arterial stiffness is of pathophysiological relevance for the development of cardiovascular disease (CVD). Data investigating this interplay using stiffness index (SI) by digital photoplethysmography are not available yet. Therefore, sex-specific relation between SI and inflammatory and hemostatic biomarkers was investigated within 13,724 subjects from the population-based Gutenberg Health Study. C-reactive protein (CRP), white blood cell count (WBCC), neopterin, interleukin-18, interleukin-1 receptor antagonist (IL-1RA), fibrinogen and hematocrit were measured. Multivariable linear regression analysis with adjustment for cardiovascular risk factors, medication, and hormonal status (in females) revealed an independent association between SI and WBCC, IL-1RA and hematocrit in both sexes, and with fibrinogen in women. There was a joint effect of increasing tertiles of SI and biomarker concentrations for future CVD risk prediction. Subjects with both SI and biomarker concentration above the median had the worst overall survival and with both below the median the best survival during a follow-up period of 6.2 ± 1.7 years, except for hematocrit. The results support the relation between inflammation, hemostasis and arterial stiffness measured by digital photoplethysmography. Markers of inflammation and hemostasis modulate the ability of SI to identify subjects at risk for future CVD or higher mortality.

Aortic stiffness and change in glomerular filtration rate and albuminuria in older people

Background

Aortic stiffness increases with age and increases pulsatile stress in the microcirculation. Abnormalities in kidney microvascular structure and function may contribute to development or progression of chronic kidney disease in older people.

Methods

We performed a longitudinal analysis of 629 community-dwelling elderly Icelandic adults from the Age, Gene/Environment Susceptibility-Reykjavik Study with two visits over a mean follow-up of 5.3 years. We evaluated the associations of carotid-femoral pulse wave velocity (CFPWV), carotid pulse pressure (CPP) and augmentation index (AI), with the change in estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) assessed as annual change and dichotomized as large changes. Models were adjusted for age, sex, height, heart rate, traditional cardiovascular disease risk factors and baseline kidney measures.

Results

When eGFR was analyzed as a continuous variable, higher baseline CFPWV and CPP, but not AI, were significantly associated with a larger annual decline in eGFR in models adjusted for age, sex, height, heart rate and baseline eGFR, but not after additional adjustment for the mean arterial pressure. When eGFR was analyzed as a categorical variable, higher CFPWV was significantly associated with a decrease in eGFR of ≥3 mL/min/1.73 m 2 /year [odds ratio (OR) 1.53, 95% confidence interval (CI) 1.11-2.13] and higher AI was associated with 30% eGFR decline during follow-up (OR 1.44 and 95% CI 1.03-2.00) in fully adjusted models. None of the tonometry measures was associated with change in UACR.

Conclusions

Abnormalities in vascular health may play a role in large declines in eGFR beyond the traditional cardiovascular disease risks in this older Icelandic cohort.

Plasma Fibroblast Growth Factor 23: Clinical Correlates and Association With Cardiovascular Disease and Mortality in the Framingham Heart Study

Background

Fibroblast growth factor 23 (FGF23) is emerging as a novel biomarker of bone metabolism, chronic kidney disease, and cardiovascular disease (CVD). However, its clinical correlates and potential predictive role in a community‐based setting are incompletely understood.

Methods and Results

We evaluated participants of the Framingham Heart Study (seventh examination cycle of the Offspring cohort plus second examination cycle of the multiethnic Omni cohort) to identify clinical correlates of plasma FGF23 (N=3236) and examine its cross‐sectional association with vascular function (N=2209), and longitudinal association with 10‐year incidence of CVD (N=2823), and all‐cause mortality (N=3223).

Circulating FGF23 concentrations were positively related to African‐American and Asian ethnicity, waist circumference, current smoking, serum glucose, history of CVD, and antihypertensive medication use; and negatively related to male sex, hormone replacement therapy, and estimated glomerular filtration rate. Multivariable‐adjusted cross‐sectional analyses showed no consistent association of FGF23 with vascular function measures. During a median follow‐up time of 10.8 years, 347 incident CVD events and 412 deaths occurred. Multivariable‐adjusted Cox regression models revealed a positive association of FGF23 with all‐cause mortality (hazard ratio [HR] per SD increase, 1.31; 95% CI, 1.20–1.42), but not with incident CVD (HR per SD increase, 1.05; 95% CI, 0.94–1.17).

Conclusions

In our large, community‐based sample, FGF23 was associated with mortality risk, but not with vascular function or incident CVD.

Clinical validation for the aldosterone-to-renin ratio and aldosterone suppression testing using simultaneous fully automated chemiluminescence immunoassays

BACKGROUND

As larger numbers of hypertensive patients are screened for primary aldosteronism with the aldosterone-to-renin ratio (ARR), automated analyzers present a practical solution for many laboratories. We report the method-specific ARR cutoff determined with direct, automated chemiluminescence immunoassays allowing the simultaneous measurement of plasma aldosterone concentrations (PACs) and plasma renin concentrations (PRCs).

METHODS

Method comparisons to commonly employed assays and tandem mass spectrometry were undertaken. Patients were previously diagnosed based on the local ARR cutoff of 1.2 (ng/dl)/(μIU/ml) in samples collected in upright seated position. Lack of aldosterone suppression in response to salt load to less than 5 ng/dl confirmed primary aldosteronism. For the new assays, the optimal ARR cutoff was established in 152 patients with essential hypertension, 93 with primary aldosteronism and 147 normotensive patients. Aldosterone suppression was assessed in 73 essential hypertensive and 46 primary aldosteronism patients.

RESULTS

PAC and PRC were significantly correlated to values determined with currently available methods (P < 0.001). In patients with primary aldosteronism, patients with essential hypertension and controls, mean (95% confidence interval) PAC was 28.4 (25.4-31.8), 6.4 (5.9-6.9) and 6.2 (5.6-6.9) ng/dl, respectively. In the same groups, PRC was 6.6 (5.6-7.7), 12.9 (11.2-14.8) and 26.5 (22.2-31.5) μIU/ml. An ARR cutoff of 1.12 provided 98.9% sensitivity and 78.9% specificity. Employing the new assay aldosterone suppression confirmed the diagnosis of primary aldosteronism and essential hypertension using the cutoff of 5 ng/dl.

CONCLUSION

Our data demonstrate that the new assays present a convenient alternative for the measurement of PAC and PRC on a single automated analyzer. Availability of these simultaneous assays should facilitate screening and diagnosis of primary aldosteronism.

Relations of circulating GDF-15, soluble ST2, and troponin-I concentrations with vascular function in the community: The Framingham Heart Study

BACKGROUND AND AIMS

Growth differentiation factor-15 (GDF-15), soluble (s)ST2, and high-sensitivity troponin-I (hs-TnI) are associated with incident cardiovascular disease (CVD) including heart failure, yet the underlying mechanisms are not fully understood. We investigated if GDF-15, sST2, and hs-TnI are related to subclinical vascular dysfunction in the community, which may explain the relations of these biomarkers with CVD.

METHODS

We evaluated 1823 Framingham Study participants (mean age 61 ± 10 years, 54% women) who underwent routine assessment of vascular function. We related circulating GDF-15, sST2, and hs-TnI concentrations to measures of arterial stiffness (carotid-femoral pulse wave velocity, CFPWV; augmentation index; and forward pressure wave amplitude, FW), endothelial-dependent vasodilation (flow-mediated dilation, FMD), and baseline and hyperemic brachial flow velocities using linear regression adjusting for standard risk factors.

RESULTS

After multivariable adjustment, GDF-15 levels were positively associated with CFPWV (0.044 [95% confidence interval 0.007-0.081] standard deviation [SD] change per SD increase in loge[GDF-15], p = 0.02) and FW (0.076 [0.026-0.126] SD change per SD increase in loge[GDF-15], p = 0.003) and inversely related to FMD (-0.051 [-0.101-0.0003] SD change per SD increase in loge[GDF-15], p = 0.048). sST2 was positively associated with CFPWV (0.032 [0.0005-0.063] SD change per SD increase in loge[sST2], p = 0.046), and hs-TnI inversely associated with hyperemic flow velocity (-0.041 [-0.082-0.0004] SD change per SD increase in loge[hs-TnI], p = 0.048).

CONCLUSION

In our community-based investigation, individual cardiac stress biomarkers were differentially related to select aspects of vascular function. These findings may contribute to the associations of circulating GDF-15, sST2, and hs-TnI with incident CVD and heart failure.

Cardiovascular disease following hematopoietic stem cell transplantation: Pathogenesis, detection, and the cardioprotective role of aerobic training

Advances in hematopoietic cell transplantation (HCT) techniques and supportive care strategies have led to dramatic improvements in relapse mortality in patients with high-risk hematological malignancies. These improvements, however, conversely increase the risk of late-occurring non-cancer competing causes, mostly cardiovascular disease (CVD). HCT recipients have a significantly increased risk of CVD-specific mortality, including elevated incidence of coronary artery disease (CAD), cerebrovascular disease, and heart failure (HF) compared to age-matched counterparts. Accordingly, there is an urgent need to identify techniques for the detection of early CVD in HCT patients to inform early prevention strategies. Aerobic training (AT) is established as the cornerstone of primary and secondary disease prevention in multiple clinical settings, and may confer similar benefits in HCT patients at high-risk of CVD. The potential benefits of AT either before, immediately after, or in the months/years following HCT have received limited attention. Here, we discuss the risk and extent of CVD in adult HCT patients, highlight novel tools for early detection of CVD, and review existing evidence in oncology and non-oncology populations supporting the efficacy of AT to attenuate HCT-induced CVD. This knowledge can be utilized to optimize treatment, while minimizing CVD risk in individuals with hematological malignancies undergoing HCT.

Circulating adhesion molecules and arterial stiffness

Aim

VCAM-1 and ICAM-1 are two important members of the immunoglobulin gene superfamily of adhesion molecules, and their potential role as biomarkers of diagnosis, severity and prognosis of cardiovascular disease has been investigated in a number of clinical studies. The aim of the present study was to determine the relationship between circulating ICAM-1 and VCAM-1 levels and aortic stiffness in patients referred for echocardiographic examination.

Methods

Aortic distensibility was determined by echocardiography using systolic and diastolic aortic diameters in 63 consecutive patients referred for echocardiography. Venous samples were collected in the morning after a 12-hour overnight fast, and serum concentrations of ICAM-1 and VCAM-1 were measured using commercial enzyme immunoassay kits.

Results

Data of a total of 63 participants (mean age 55.6 ± 10.5 years, 31 male) were included in the study. Circulating levels of adhesion molecules were VCAM-1: 12.604 ± 3.904 ng/ml and ICAM-1: 45.417 ± 31.429 ng/ml. We were unable to demonstrate any correlation between indices of aortic stiffness and VCAM-1 and ICAM-1 levels.

Conclusion

The role of soluble adhesion molecules in cardiovascular disease has not been fully established and clinical studies show inconsistent results. Our results indicate that levels of circulating adhesion molecules cannot be used as markers of aortic stiffness in patients.

The association between sleep-disordered breathing and aortic stiffness in a community cohort

OBJECTIVE

Sleep-disordered breathing is associated with hypertension and cardiovascular disease. Increased aortic stiffness is one possible linking mechanism. We evaluated the association between sleep-disordered breathing and aortic stiffness in a community-based sample.

METHODS

Our community-based cross-sectional observational study included 381 participants from the Framingham Heart Study (55% women, mean age 58.0 S.D. = 9.4 years, 51% ethnic minorities). Polysomnographically derived apnea-hypopnea index and CT90% (cumulative % sleep time with oxyhemoglobin saturation <90%) quantified sleep-disordered breathing severity. Carotid-femoral pulse wave velocity, the gold-standard measure of aortic stiffness, was calculated using arterial applanation tonometry-derived waveforms and body surface measured transit distance. We assessed associations between sleep-disordered breathing and carotid-femoral pulse wave velocity using multivariable regression. We adjusted for age, sex, race, body mass index, diabetes, alcohol consumption, hormone replacement therapy, cholesterol/high-density lipoprotein, lipid-lowering therapy, anti-hypertensive medication, smoking, hypertension, and prevalent cardiovascular disease.

RESULTS

After multivariable adjustment, carotid-femoral pulse wave velocity was associated with both apnea-hypopnea index (β = 0.03, 95% CI: 0.002-0.07, p= 0.04) and CT90% (β = 0.05, 95% CI: 0.005-0.1, p= 0.03). The adjusted mean carotid-femoral pulse wave velocity was 9.43 (95% CI: 9.12-9.74), 9.76 (95% CI: 9.25-10.26), and 10.15 (95% CI: 9.37-10.92) m/s, respectively, in subjects with apnea-hypopnea index <5, 5-14.9, and ≥15 events/h.

CONCLUSIONS

In a community-based sample of middle aged and older men and women, sleep-disordered breathing was associated with increased carotid-femoral pulse wave velocity, a strong predictor of cardiovascular risk.

Plasma Homocysteine is a Predictive Factor for Arterial Stiffness: A Community-Based 4.8-Year Prospective Study

The authors investigated whether plasma total homocysteine (tHcy) is a predictive factor for arterial stiffness (carotid-femoral pulse wave velocity [cf-PWV] and carotid-radial PWV) in 1447 patients from a 4.8-year prospective study in Beijing, People's Republic of China. Baseline tHcy showed a significant relationship with follow-up cf-PWV (β=0.817, P=.015) in a multivariable linear regression analysis. A stepwise logistic regression model showed that baseline levels of tHcy were significantly associated with follow-up cf-PWV in the adjusted models. Furthermore, the baseline tHcy levels showed a significant association with increases in cf-PWV. There was no association between the change in tHcy and increase in PWV. The present study clearly demonstrated an association between tHcy levels and arterial stiffness, indicating that tHcy is an independent predictive factor for arterial stiffness in a community-based population.

Plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women

Objectives

To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a community-based cohort. The gender differences in these associations were examined.

Methods

We evaluated the relationship between plasma homocysteine levels to three measures of vascular function [carotid-femoral pulse wave velocity (CF-PWV), carotid-ankle PWV (CA-PWV) and heart rate corrected augmentation index (AI)] in 1680 participants (mean age: 61.5 years; 709 men, 971 women) from communities of Beijing, China.

Results

In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV (r = 0.211, P < 0.0001) and CA-PWV (r = 0.148, P < 0.0001), whereas inversely associated with AI (r = −0.052, P = 0.016). In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV (standardized β = 0.065, P = 0.007) in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV (standardized β = 0.082, P = 0.023) in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women.

Conclusions

In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.

The effect of folate fortification on folic acid-based homocysteine-lowering intervention and stroke risk: a meta-analysis

OBJECTIVE

Folate and vitamin B12 are two vital regulators in the metabolic process of homocysteine, which is a risk factor of atherothrombotic events. Low folate intake or low plasma folate concentration is associated with increased stroke risk. Previous randomized controlled trials presented discordant findings in the effect of folic acid supplementation-based homocysteine lowering on stroke risk. The aim of the present review was to perform a meta-analysis of relevant randomized controlled trials to check the how different folate fortification status might affect the effects of folic acid supplementation in lowering homocysteine and reducing stroke risk.

DESIGN

Relevant randomized controlled trials were identified through formal literature search. Homocysteine reduction was compared in subgroups stratified by folate fortification status. Relative risks with 95 % confidence intervals were used as a measure to assess the association between folic acid supplementation and stroke risk.

SETTING

The meta-analysis included fourteen randomized controlled trials,

SUBJECTS

A total of 39 420 patients.

RESULTS

Homocysteine reductions were 26·99 (sd 1·91) %, 18·38 (sd 3·82) % and 21·30 (sd 1·98) %, respectively, in the subgroups without folate fortification, with folate fortification and with partial folate fortification. Significant difference was observed between the subgroups with folate fortification and without folate fortification (P=0·05). The relative risk of stroke was 0·88 (95 % CI 0·77, 1·00, P=0·05) in the subgroup without folate fortification, 0·94 (95 % CI 0·58, 1·54, P=0·82) in the subgroup with folate fortification and 0·91 (95 % CI 0·82, 1·01, P=0·09) in the subgroup with partial folate fortification.

CONCLUSIONS

Folic acid supplementation might have a modest benefit on stroke prevention in regions without folate fortification.

Multimarker Analysis for New Biomarkers in Relation to Central Arterial Stiffness and Hemodynamics in a Chinese Community-Dwelling Population

Central arterial stiffness and hemodynamics independently reflect the risk of cardiovascular events. This Chinese community-based analysis was performed to evaluate the relationships of new biomarkers with central arterial stiffness and hemodynamics by a multimarker method. This analysis consisted of 1540 participants who were fully tested for the new biomarkers including N-terminal prohormone of brain natriuretic peptide, lipid accumulation product, triglyceride-high-density lipoprotein cholesterol (TG-HDL-c) ratio, uric acid, high-sensitivity C-reactive protein, and homocysteine. Carotid-femoral pulse wave velocity (cfPWV), central pulse pressure (cPP), and central augmentation index (cAIx) were measured. The median (range) age of entire cohort was 62 years (21-96 years), and 40.5% were males. The median (interquartile range) of cfPWV, cPP, and cAIx was 11.0 m/s (9.6-13.0 m/s), 42 mm Hg (35-52 mm Hg), and 28% (21%-33%), respectively. In multivariate analysis, participants with higher cfPWV had significantly higher age, peripheral pulse pressure, TG, TG-HDL-c ratio, and homocysteine levels compared with others (P < .05 for all). Multimarker analysis in a Chinese community-dwelling population reinforced the potential clinical value of plasma TG-HDL-c ratio and homocysteine levels as the biomarkers of increased arterial stiffness.

The relation of red blood cell fatty acids with vascular stiffness, cardiac structure and left ventricular function: the Framingham Heart Study

Polyunsaturated fatty acids have been associated with beneficial influences on cardiovascular health. However, the underlying mechanisms are not clear, and data on the relations of polyunsaturated fatty acids to subclinical disease measures such as vascular stiffness and cardiac function are sparse and inconclusive. In a large community-based cohort, we examined the relations of omega-3 and other fatty acids to a comprehensive panel of vascular function measures (assessing microvascular function and large artery stiffness), cardiac structure and left ventricular function. Red blood cell (RBC) membrane fatty acid composition, a measure of long-term fatty acid intake, was assessed in participants of the Framingham Offspring Study and Omni cohorts and related to tonometry-derived measures of vascular stiffness and to a panel of echocardiographic traits using partial correlations. Up to n=3055 individuals (56% women, mean age 66 years) were available for analyses. In age- and sex-adjusted models, higher RBC omega-3 content was moderately associated (p≤0.002) with several measures of vascular stiffness and function in a protective direction. However, after multivariable adjustment, only an association of higher RBC omega-3 content with lower carotid-femoral pulse wave velocity (a measure of aortic stiffness) remained significant (r = -0.06, p=0.002). In secondary analyses, higher linoleic acid, the major nutritional omega-6 fatty acid, was associated with smaller left atrial size, even after multivariable adjustment (r = -0.064, p<0.001). In conclusion, in our cross-sectional community-based study, we found several associations consistent with the notion of protective effects of omega-3 and linoleic acid. The clinical significance of these modest associations remains to be elucidated.

Efficacy and safety of mineralocorticoid receptors in mild to moderate arterial hypertension

The mineralocorticoid receptor antagonists have been shown to have favourable safety and cost-effectiveness profiles across a broad range of clinical indications, including heart failure, primary aldosteronism and resistant hypertension. The clinical biology of the first aldosterone blocker, i.e. spironolactone, and its effects in several organ systems has been well elucidated from multiple studies. The range of adverse effects experienced with spironolactone has led to its modification and the consequent synthesis of eplerenone. Scientific evidence accumulated so far supports the role of eplerenone as first-choice drug in heart failure, with lower prevalence rates of sex-related adverse effects associated with eplerenone as compared to spironolactone. In Europe, eplerenone is currently marketed only in some countries and only with the indication of heart failure, whereas its clinical efficacy and safety in mild to moderate hypertension is said to be uncertain. A review of available scientific evidence, however, discloses that 11 randomized clinical trials assessing eplerenone in >3500 hypertensives have been reported so far. The results of these studies clearly show that eplerenone is an effective antihypertensive agent when used alone or in combination with other medications. In doses ranging from 25 to 100mg daily, eplerenone monotherapy results in a dose-dependent reduction in clinic blood pressure. As compared to placebo, eplerenone reduces significantly blood pressure from baseline. In general, 100mg daily eplerenone has a blood pressure lowering that is 50 to 75% that of spironolactone. Eplerenone results in a greater reduction in blood pressure as compared with losartan, and comparison between eplerenone and amlodipine shows that both treatments decrease systolic blood pressure to a similar extent but eplerenone is better tolerated. In conclusion, there is now evidence that eplerenone can play an important role in the treatment of mild to moderate arterial hypertension and therefore scientific experts and regulatory authorities should support its wider use in clinical practice worldwide.

SIRT1-mediated epigenetic downregulation of plasminogen activator inhibitor-1 prevents vascular endothelial replicative senescence

The inactivation of plasminogen activator inhibitor-1 (PAI-1) has been shown to exert beneficial effects in age-related vascular diseases. Limited information is available on the molecular mechanisms regarding the negatively regulated expression of PAI-1 in the vascular system. In this study, we observed an inverse correlation between SIRT1, a class III histone deacetylase, and PAI-1 expression in human atherosclerotic plaques and the aortas of old mice, suggesting that internal negative regulation exists between SIRT1 and PAI-1. SIRT1 overexpression reversed the increased PAI-1 expression in senescent human umbilical vein endothelial cells (HUVECs) and aortas of old mice, accompanied by decreased SA-β-gal activity in vitro and improved endothelial function and reduced arterial stiffness in vivo. Moreover, the SIRT1-mediated inhibition of PAI-1 expression exerted an antisenescence effect in HUVECs. Furthermore, we demonstrated that SIRT1 is able to bind to the PAI-1 promoter, resulting in a decrease in the acetylation of histone H4 lysine 16 (H4K16) on the PAI-1 promoter region. Thus, our findings suggest that the SIRT1-mediated epigenetic inhibition of PAI-1 expression exerts a protective effect in vascular endothelial senescence.

"Inflammation and arterial stiffness in humans"

Arterial stiffness is an established marker of cardiovascular morbidity and mortality and a potential therapeutic target. While hypertension and aging are established factors contributing to arterial stiffness, the role of inflammation in stiffening of the arteries is less well understood. We summarize existing literature regarding inflammation and arterial stiffness, including a discussion of the potential mechanisms by which inflammation may lead to arterial stiffening and studies assessing: (1) The association between subclinical inflammation and arterial stiffness in the general population; (2) The presence of increased arterial stiffness in primary inflammatory diseases; (3) The effect of anti-inflammatory therapy on arterial stiffness in primary inflammatory disease including the effect of statins; (4) Experimental evidence of immunization-induced arterial stiffening in normal adults. We discuss potential opportunities to assess the impact of anti-inflammatory interventions on arterial stiffness in subjects without primary inflammatory conditions. We also review the effect of inflammation on wave reflections.

Plasma plasminogen activator inhibitor-1 predicts myocardial infarction in HIV-1-infected individuals

OBJECTIVES

Biomarkers of endothelial dysfunction, inflammation and coagulation are associated with atherosclerosis and cardiovascular disease, but their association and possible predictive value remain controversial among HIV-1-infected individuals. We sought to investigate the association of seven biomarkers with first-time myocardial infarction (MI) in an HIV-1-infected population.

DESIGN

A matched case-control study of 54 cases and 54 controls.

METHODS

We compared 54 HIV-1-infected patients with verified first-time MI and 54 HIV-1-infected controls matched for age, duration of antiretroviral therapy, sex, smoking and no known cardiovascular disease. Levels of high-sensitivity C-reactive protein, soluble endothelial selectin, soluble vascular cell adhesion molecule, soluble intercellular adhesion molecule, matrix metalloprotease 9, myeloperoxidase, and plasminogen activator inhibitor 1 (PAI-1) were measured using a Luminex assay in plasma samples from routine visits both 12 and 2 months prior to the case patient's MI.

RESULTS

The two groups had similar HIV characteristics and traditional cardiovascular risk factors. In univariate analysis, PAI-1 levels were associated with MI, whereas none of the other markers showed any association.In multivariate analyses adjusting for the D:A:D risk score, HIV viral load and high-sensitivity C-reactive protein, PAI-1 levels in the highest quartile were associated with a six to seven-fold increased risk of MI in both samples.

CONCLUSION

High levels of PAI-1 were associated with risk of first-time MI in HIV-1-infected individuals independently of cardiovascular risk factors, HIV parameters and antiretroviral therapy. Therefore PAI-1 may be used for risk stratification and prediction of CHD, but further studies are needed.

Relationship of coagulation and fibrinolytic variables with arterial structure and function in Africans

INTRODUCTION

Although both coagulation and fibrinolysis are associated with cardiovascular disease (CVD) the underlying nature and pathways of many of these associations are still unclear. Our aim was to determine which of the current or 5-year prior levels of total fibrinogen, fibrinogen γ', plasminogen activator inhibitor-1 (PAI-1act) and global fibrinolytic potential were the stronger determinant of arterial structure and function.

MATERIALS AND METHODS

This prospective study consisted of 2010 Africans over the age of 35 years with 5-year follow-up data available for 1288 participants. Cardiovascular measurements included arterial stiffness, blood pressure and carotid intima media thickness.

RESULTS

Fibrinogen γ' showed stronger associations with blood pressure than total fibrinogen also in the presence of other CVD risk factors. PAI-1act was positively associated with blood pressure both cross-sectionally and prospectively, with the longitudinal association being the stronger determinant, also after adjustment for known CVD risk factors. Clot lysis time (CLT) was positively associated, both prospectively and cross-sectionally, with intima media thickness and negatively with markers of arterial stiffness but not after adjustment for known CVD risk factors.

CONCLUSIONS

Fibrinogen γ' was more strongly associated with CVD function than total fibrinogen. PAI-1act was significantly associated with blood pressure with changes in PAI-1 levels preceding changes in blood pressure. Different mechanisms may be at play determining arterial wall stiffness/thickening and blood pressure as observed from the opposing associations with PAI-1act and CLT. CLT was not independently related to cardiovascular measures as its associations were weakened in the presence of other known CVD risk factors.