Arterial stiffness in renal patients: an update

Effect of Lanthanum Carbonate on Serum Phosphate, Oxidative Stress, and Vascular Dysfunction in CKD: A Mechanistic Randomized Controlled Trial

Key Points

A key mechanism contributing to vascular dysfunction in CKD is increased oxidative stress. Lanthanum carbonate did not discernibly affect vascular endothelial function, arterial stiffness, or markers of endothelial oxidative stress.

Background

Vascular endothelial dysfunction and arterial stiffness are common in CKD and independently predict cardiovascular disease. Elevated serum phosphorus, even within the normal range, associates with cardiovascular disease and mortality in CKD. Excess phosphorus may increase oxidative stress leading to vascular dysfunction.

Methods

This is a randomized double-blind trial in which we compared lanthanum carbonate, a noncalcium phosphate binder, with placebo on vascular function and endothelial and circulating measures of oxidative stress and inflammation in 54 participants with CKD 3b–4 and normal phosphorus levels. Primary end points were change in brachial artery flow-mediated dilation (FMDBA) and carotid-to-femoral pulse-wave velocity (cfPWV) at 12 weeks. Mechanistic end points were changes from baseline in FMDBA after ascorbic acid infusion and circulating and endothelial markers of oxidative stress and inflammation.

Results

The age was 65±8 years and eGFR was 38±14 ml/min per 1.73 m2. At 12 weeks, serum phosphorus did not change with lanthanum (3.44±0.47 versus 3.44±0.52 mg/dl; P = 0.94) but tended to increase with placebo (3.42±0.80 versus 3.74±1.26 mg/dl; P = 0.09). FMDBA and cfPWV did not change from baseline in either group: FMDBA lanthanum 3.13%±2.87% to 2.73%±2.48% versus placebo 3.74%±2.86% to 3.09%±2.49% (P = 0.67); CfPWV lanthanum 1214±394 to 1216±322 cm/s versus placebo 993±289 to 977±254 cm/s (P = 0.77). Ascorbic acid infusion to inhibit oxidative stress did not differentially affect FMDBA. Circulating and endothelial markers of oxidative stress and inflammation did not differ between groups.

Conclusions

Lanthanum carbonate did not discernibly affect vascular endothelial function, arterial stiffness, or markers of endothelial oxidative stress among participants with CKD 3b–4 and normophosphatemia.

The comparison of paricalcitol and calcitriol effects on pulse wave velocity, osteocalcin, and fetuin-A in chronic hemodialysis patients

INTRODUCTION

Vascular calcification is an intervenable factor in the pathophysiology of cardiovascular disease. Treatment-related factors might worsen the arterial stiffness in chronic hemodialysis patients. The aim of the study is to compare the effects of 1-year treatment with paricalcitol or calcitriol on pulse wave velocity (PWV), which is an indicator of arterial stiffness and osteocalcin and fetuin-A levels.

METHODS

Seventy-six hemodialysis patients who had similar PWV1 at the beginning were evaluated after a 1-year treatment of paricalcitol or calcitriol. PWV2, serum osteocalcin, and fetuin-A levels were measured at the end of the study.

RESULTS

At the end of the study, PWV2 of paricalcitol group was statistically lower than the calcitriol group. Osteocalcin levels were statistically lower and fetuin-A levels were statistically higher in the paricalcitol group than the calcitriol group at the end of the study. The number of patients with PWV2 > 7 m/s and using paricalcitol was 16 (39%) but 25 (41%) patients were using calcitriol; the differences were statistically significant.

CONCLUSIONS

The long-term benefits of paricalcitol were superior to the benefits of calcitriol. Paricalcitol has protective effects from vascular calcification in chronic hemodialysis patients.

Effect of regulated vitamin D increase on vascular markers in patients with chronic kidney disease: A systematic review and meta-analysis of randomized controlled trials

AIM

The effect of increased vitamin D levels on vascular function in patients with chronic kidney disease (CKD) is controversial. This meta-analysis aimed to assess the effect of regulated vitamin D increase on vascular markers in patients with CKD.

DATA SYNTHESIS

We searched PubMed, Web of Science, Embase and ClinicalTrials.gov from database inception up until July 21, 2023. We included randomized controlled trials assessing the effects of using vitamin D and its analogues on vascular function in patients with CKD. Fixed-effects and random-effects model analyses were performed using weighted mean difference effects for each trial by heterogeneity (I2) assessment. Primary outcomes encompassed blood flow-mediated dilation (FMD)、pulse wave velocity (PWV) and augmentation index (AIx).

FINDINGS

From 1964 records we selected 12 trials, 5 (n = 331) on FMD, 8 (n = 626) on PWV and 4 (n = 393) on AIx. Vitamin D and VDRA supplementation failed to significantly improve FMD (WMD 1.68%; 95% CI -0.18 to 3.53; P = 0.08; I2 = 88%)、PWV (WMD -0.41 m/s; 95%CI -0.95 to 0.13; P = 0.14; I2 = 57%)and AIx (WMD -0.53%; 95%CI -1.69 to 0.63; P = 0.37; I2 = 0%). Subgroup analysis revealed that 2 μg paricalcitol significantly improved FMD (WMD 2.09%; 95%CI 1.28 to 2.90; P < 0.00001); I2 = 0%), as did cholecalciferol (WMD 5.49%; 95% CI 4.35 to 6.63; P < 0.00001).

CONCLUSION

Supplementation vitamin D and VDRA are associated with improved vascular function as measured by FMD, but not arterial stiffness as measured by PWV and AIx, tentatively suggesting that regulating the increase of vitamin D could not potentially reduce the incidence of cardiovascular disease.

Nonpharmacological Management of Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease is a slowly progressive, lifelong disease characterized by continuous development and enlargement of kidney cysts. Thus, nonpharmacological interventions are crucial in disease management and have the potential for a large clinical impact as standalone interventions or in conjunction with pharmacological therapies. Current potential strategies regarding nonpharmacological management of autosomal dominant polycystic kidney disease include nonpharmacological management of blood pressure, calorie restriction, weight loss or weight management, enhanced hydration, limiting caffeine, dietary sodium restriction, protein restriction or altering the type of protein intake, phosphorus restriction, and reducing net acid load. This brief review discusses the available evidence, including cell culture, animal, epidemiological, and clinical studies, regarding the utility of such strategies in the nonpharmacological management of autosomal dominant polycystic kidney disease. We assert that lifestyle modification strategies should be a critical aspect of the treatment of autosomal dominant polycystic kidney disease, while further trial and mechanistic evidence continue to become available.

Curcumin Therapy to Treat Vascular Dysfunction in Children and Young Adults with ADPKD: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Clinical manifestations of autosomal dominant polycystic kidney disease (ADPKD), including evidence of vascular dysfunction, can begin in childhood. Curcumin is a polyphenol found in turmeric that reduces vascular dysfunction in rodent models and humans without ADPKD. It also slows kidney cystic progression in a murine model of ADPKD. We hypothesized that oral curcumin therapy would reduce vascular endothelial dysfunction and arterial stiffness in children/young adults with ADPKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a randomized, placebo-controlled, double-blind trial, 68 children/young adults 6-25 years of age with ADPKD and eGFR>80 ml/min per 1.73 m² were randomized to either curcumin supplementation (25 mg/kg body weight per day) or placebo administered in powder form for 12 months. The coprimary outcomes were brachial artery flow-mediated dilation and aortic pulse-wave velocity. We also assessed change in circulating/urine biomarkers of oxidative stress/inflammation and kidney growth (height-adjusted total kidney volume) by magnetic resonance imaging. In a subgroup of participants ≥18 years, vascular oxidative stress was measured as the change in brachial artery flow-mediated dilation following an acute infusion of ascorbic acid.

RESULTS

Enrolled participants were 18±5 (mean ± SD) years, 54% were girls, baseline brachial artery flow-mediated dilation was 9.3±4.1% change, and baseline aortic pulse-wave velocity was 512±94 cm/s. Fifty-seven participants completed the trial. Neither coprimary end point changed with curcumin (estimated change [95% confidence interval] for brachial artery flow-mediated dilation [percentage change]: curcumin: 1.14; 95% confidence interval, -0.84 to 3.13; placebo: 0.33; 95% confidence interval, -1.34 to 2.00; estimated difference for change: 0.81; 95% confidence interval, -1.21 to 2.84; P=0.48; aortic pulse-wave velocity [centimeters per second]: curcumin: 0.6; 95% confidence interval, -25.7 to 26.9; placebo: 6.5; 95% confidence interval, -20.4 to 33.5; estimated difference for change: -5.9; 95% confidence interval, -35.8 to 24.0; P=0.67; intent to treat). There was no curcumin-specific reduction in vascular oxidative stress or changes in mechanistic biomarkers. Height-adjusted total kidney volume also did not change as compared with placebo.

CONCLUSIONS

Curcumin supplementation does not improve vascular function or slow kidney growth in children/young adults with ADPKD.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Curcumin Therapy to Treat Vascular Dysfunction in Children and Young Adults with ADPKD, NCT02494141.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_02_07_CJN08950621.mp3.

Subclinic arterial and left ventricular systolic impairment in autosomal dominant polycystic kidney disease with preserved renal functions

Subclinical atherosclerosis and cardiovascular events are common even in young normotensive patients with autosomal dominant polycystic kidney disease (ADPKD). Our aim was to examine the relationship between serum fibroblast growth factor-23 (FGF-23) levels, left ventricular global longitudinal strain (LV-GLS), arterial stiffness (AS), and carotid intima-media thickness (CIMT) in patients with ADPKD with preserved kidney function. The relationship between albuminuria, AS, LV-GLS, CIMT, 24-hour ambulatory blood pressure measurement, and FGF-23 was examined in 52 normotensive and hypertensive patients with ADPKD and a matched control group of 35 subjects. AS was assesed with brachial-ankle pulse wave velocity, LV-GLS was measured with speckle-tracking echocardiography. FGF-23 was measured with enzyme-linked immunosorbent assay. The microalbumin/creatinine ratio was significantly higher in the ADPKD group than in the control group (p?<?0.001). Serum FGF-23 levels were similar between the study and control group. LV-GLS value tended to be impaired and CIMT to be higher in the ADPKD group compared to controls (?18.1?±?2.6 vs. -19.4?±?3.1?%, p?=?0.08; 0.75?±?0.1 vs. 0.68?±?0.1 mm, p?=?0.09, respectively). The augmentation index was significantly higher in the ADPKD group than in the control group (26.2?±?12.5 vs. 16.4?±?11.2 mmHg/mmHg, p?=?0.01). Our study supports subclinical impairment in arterial and cardiac functions in the early period of ADPKD. However, none of these factors was found to be associated with serum FGF-23 levels.

The relationship between hepatic fibrosis and arterial stiffness in hemodialysis patients

INTRODUCTION

The main cause of death in hemodialysis patients is cardiovascular diseases. Increased arterial stiffness is a predictor of cardiovascular events for hemodialysis patients. Among the nondialysis patient population, arterial stiffness increases in those with hepatic fibrosis and nonalcoholic fatty liver disease. This study aims to examine the relationship between hepatic fibrosis and arterial stiffness in hemodialysis patients for the first time in the literature.

MATERIAL AND METHOD

The study includes chronic hemodialysis patients over 18 years of age who had been treated for hemodialysis for at least 6 months. Patients with chronic liver disease, chronic viral hepatitis (HBV and HCV), alcohol use, or liver disease accompanied by polycystic kidney disease and active infection were excluded. Hepatic fibrosis scores were measured using the FibroScan device. Single-cuff Mobil-o-Graph was used for measurement of arterial stiffness.

RESULTS

Fifty-nine patients were enrolled; 54.2% of the patients were male, and the mean age was 53.9 ± 12.9 years. Thirty-nine percent of the patients had diabetes. Average pulse wave velocity (PWV) value of the patients was 8.3 ± 1.6 m/s, and it had positive correlation with age, CAP score, fibrosis score, and body mass index and showed negative correlation to albumin. It was seen that the patients with a PWV value ≥ 10 m/s have significantly higher CAP score compared with the patients with a PWV < 10 m/s. When the factors predicting PWV were examined in the regression analysis, age and systolic blood pressure were found to be determinants.

CONCLUSION

Increased hepatic fibrosis in hemodialysis patients is associated with increased arterial stiffness, but this relationship is not independent.

Angioplasty Induced Changes in Dialysis Vascular Access Compliance

Dialysis vascular access remains vitally important to maintain life and functional capacity with end stage renal disease. Angioplasty is an integral part of maintaining dialysis access function and patency. To understand the effect of angioplasty balloon dilation on vascular wall mechanics, we conducted a clinical study to evaluate the elastic modulus of the anastomosis in five subjects with anastomosis stenoses, before and after six angioplasty procedures, using B-mode ultrasound DICOM data. A novel and open source vascular ultrasound high-resolution speckle tracking software tool was used. The median lumen diameter increased from 3.4 to 5.5 mm after angioplasty. Meanwhile, the median elastic modulus of the 18 measurements at the anastomosis increased by 52.2%, from 2.24 × 10³ to 3.41 × 10³ mmHg. The results support our hypothesis that the structural changes induced in the vessel wall by balloon dilation lead to reduced vascular compliance and a higher elastic modulus of the vessel wall.

Effects of Caloric Restriction Diet on Arterial Hypertension and Endothelial Dysfunction

The most common manifestation of cardiovascular (CV) diseases is the presence of arterial hypertension (AH), which impacts on endothelial dysfunction. CV risk is associated with high values of systolic and diastolic blood pressure and depends on the presence of risk factors, both modifiable and not modifiable, such as overweight, obesity, physical exercise, smoking, age, family history, and gender. The main target organs affected by AH are the heart, brain, vessels, kidneys, and eye retina. AH onset can be counteracted or delayed by adopting a proper diet, characterized by a low saturated fat and sodium intake, a high fruit and vegetable intake, a moderate alcohol consumption, and achieving and maintaining over time the ideal body weight. In this review, we analyzed how a new nutritional approach, named caloric restriction diet (CRD), can provide a significant reduction in blood pressure values and an improvement of the endothelial dysfunction. In fact, CRD is able to counteract aging and delay the onset of CV and neurodegenerative diseases through the reduction of body fat mass, systolic and diastolic values, free radicals production, and oxidative stress. Currently, there are few studies on CRD effects in the long term, and it would be advisable to perform observational studies with longer follow-up.

Curcumin therapy to treat vascular dysfunction in children and young adults with autosomal dominant polycystic kidney disease: Design and baseline characteristics of participants

Although often considered to be a disease of adults, complications of autosomal dominant polycystic kidney disease (ADPKD) begin in childhood. While the hallmark of ADPKD is the development and continued growth of multiple renal cysts that ultimately result in loss of kidney function, cardiovascular complications are the leading cause of death among affected patients. Vascular dysfunction (endothelial dysfunction and large elastic artery stiffness) is evident very early in the course of the disease and appears to involve increased oxidative stress and inflammation. Treatment options to prevent cardiovascular disease in adults with ADPKD are limited, thus childhood may represent a key therapeutic window. Curcumin is a safe, naturally occurring polyphenol found in the Indian spice turmeric. This spice has a unique ability to activate transcription of key antioxidants, suppress inflammation, and reduce proliferation. Here we describe our ongoing randomized, placebo-controlled, double-blind clinical trial to assess the effect of curcumin therapy on vascular function and kidney growth in 68 children and young adults age 6–25 years with ADPKD. Baseline demographic, vascular, and kidney volume data are provided. This study has the potential to establish a novel, safe, and facile therapy for the treatment of arterial dysfunction, and possibly renal cystic disease, in an understudied population of children and young adults with ADPKD.

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Evaluating a strategy to intervene early in the course of ADPKD.

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Assessing two major contributors to arterial dysfunction and CVD risk in ADPKD.

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Curcumin is a novel nutraceutical that is an safe, naturally occurring, and facile.

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Using a translational approach is used to assess physiological mechanisms.

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Gaining exploratory evidence on the efficacy of curcumin to slow kidney growth.

Changes in aortic pulse wave velocity in peritoneal dialysis do not mirror changes in extracellular water measured by bioimpedance

BACKGROUND

Pulse wave velocity is a measurement of arterial stiffness and associated with increased cardiovascular mortality. Previous reports in peritoneal dialysis have linked increased pulse wave velocity with an expansion in extracellular water. As cardiovascular mortality is increased in peritoneal dialysis patient, we wished to determine whether changes in pulse wave velocity mirrored changes in extracellular water.

METHODS

We repeated aortic pulse wave velocity and bioimpedance-derived extracellular water measurements in peritoneal dialysis patients attending for assessment of peritoneal membrane function.

RESULTS

Sixty-six patients, 41 males (62.1%), mean age of 66.2 ± 13.9 years, median duration of peritoneal dialysis treatment (14.3 (3.1-31.9) months) had repeated measurement 6.4 (5.8-10.2) months apart, with no significant change in aortic pulse wave velocity (10.1 ± 3.2 to 9.9 ± 2.8 m/s). In univariate analysis, the initial aortic pulse wave velocity was associated with extracellular water (r = 0.26, p = 0.034) and serum N-terminal pro brain-type natriuretic peptide (r = 0.25, p = 0.04), and on follow-up, aortic pulse wave velocity with N-terminal pro brain-type natriuretic peptide (r = 0.31, p = 0.01). Aortic pulse wave velocity increased in 50% of patients, and these patients had greater serum C-reactive protein 3(2-10) versus 2(1-4) mg/L, and ferritin (778(444-1099) versus 585(313-811), p < 0.05), but there were no differences in either absolute or adjusted extracellular water. Both log C-reactive protein (odds ratio 4.7 (95% confidence limits 1.3-17.1), p = 0.019) and prescription of calcium channel blockers (odds ratio 4.9 (95% confidence limits 1.2-19.1), p = 0.024) were independently associated with an increase in aortic pulse wave velocity.

CONCLUSION

We did not find an independent association between a change in aortic pulse wave velocity and extracellular water, suggesting that changes in aortic stiffness in peritoneal dialysis patients are more complex than simply following changes in extracellular water.

Aortic Pulse Wave Velocity in Peritoneal Dialysis Patients Is Not Simply Associated with Extracellular Water Expansion

BACKGROUND

Cardiac death is increased in peritoneal dialysis (PD) patients. Pulse wave velocity (PWV) is a measurement of arterial stiffness, and previous reports linked PWV to increased extracellular water (ECW). As cyclers and icodextrin are increasingly used, we wished to determine whether this association between PWV and ECW remains.

METHODS

We measured aortic PWV (aPWV) and bioimpedance (InBody, Seoul, South Korea) in consecutive PD patients attending for peritoneal membrane testing.

RESULTS

189 patients were included, 62.4% male, mean age 63.1 ± 15.2 years, 45.3% diabetic, median dialysis duration 12.3 (6.5-25.1) months, 71.4% using cyclers, weight 73.0 ± 16.1 kg, systolic blood pressure 142 ± 21 mm Hg, aPWV 10.4 ± 5.1 m/s. aPWV was associated with pulse pressure (r = 0.26, p = 0.001), Davies comorbidity score (r = 0.18, p = 0.013), and N-terminal pro-brain-type natriuretic peptide (NTproBNP; r = 0.18, p = 0.011). Patients with aPWV ≥10 m/s were older (65.9 ± 13.6 vs. 60.1 ± 16.3 years, p < 0.01) with a higher ECW-to-total body water ratio (0.400 ± 0.012 vs. 0.396 ± 0.013, p < 0.05), but ECW/height was not different (8.52 ± 2.32 vs. 8.75 ± 1.78 L/m), as was NTproBNP (2,472 [788-5,422] vs. 1,234 [410-6,230] ng/L). On multivariable testing, aPWV was positively associated with β-blocker prescription (standardised β coefficient [Stβ] 0.3, 95% confidence limits [95% CL] 0.7-2.6, p = 0.001) and negatively with icodextrin prescription (Stβ 0.19, 95% CL -0.2 to -2.1, p = 0.04).

CONCLUSIONS

Compared to previous studies, we did not find an independent association between aPWV and ECW and estimates of ECW excess, using the InBody bioimpedance device, suggesting that vascular stiffness in PD patients is more complex than simple ECW volume expansion in PD patients.

Mineralocorticoid Antagonism and Vascular Function in Early Autosomal Dominant Polycystic Kidney Disease: A Randomized Controlled Trial

RATIONALE & OBJECTIVE

Vascular dysfunction, characterized by impaired vascular endothelial function and increased large-elastic artery stiffness, is evident early in autosomal dominant polycystic kidney disease (ADPKD) and is an important predictor of cardiovascular events and mortality. Aldosterone excess has been implicated in the development of endothelial dysfunction and arterial stiffness, in part by causing increased oxidative stress and inflammation. We hypothesized that aldosterone antagonism would reduce vascular dysfunction in patients with early-stage ADPKD.

STUDY DESIGN

Prospective, randomized, controlled, double-blind, clinical trial.

SETTING & PARTICIPANTS

61 adults aged 20 to 55 years with ADPKD, estimated glomerular filtration rate ≥ 60mL/min/1.73m², and receiving a renin-angiotensin-aldosterone system inhibitor.

INTERVENTION

Spironolactone (maximum dose, 50mg/d) or placebo for 24 weeks.

OUTCOMES

Change in brachial artery flow-mediated dilation (FMD_BA) was the primary end point and change in carotid-femoral pulse-wave velocity (CFPWV) was the secondary end point.

RESULTS

60 participants completed the trial. Participants had a mean age of 34±10 (SD) years, 54% were women, and 84% were non-Hispanic white. Spironolactone did not change FMD_BA (8.0% ± 5.5% and 7.8% ± 4.3% at baseline and 24 weeks, respectively, vs corresponding values in the placebo group of 8.4% ± 6.2% and 8.0% ± 4.6%; P=0.9for comparison of change between groups) or CFPWV (640±127 and 603±101cm/s at baseline and 24 weeks, respectively, vs corresponding values in the placebo group of 659±138 and 658±131cm/s; P=0.1). Brachial systolic blood pressure was reduced with spironolactone (median change, -6 [IQR, -15, 1] vs -2 [IQR, -7, 10] mm Hg in the placebo group; P=0.04). Spironolactone did not change the majority of circulating and/or endothelial cell markers of oxidative stress/inflammation and did not change vascular oxidative stress.

LIMITATIONS

Low level of baseline vascular dysfunction; lack of aldosterone measurements.

CONCLUSIONS

24 weeks of aldosterone antagonism reduced systolic blood pressure without changing vascular function in patients with early-stage ADPKD.

FUNDING

NIDDK, NIH National Center for Advancing Translational Sciences, and the Zell Family Foundation.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT01853553.

Impact of hemodialysis on cardiovascular system assessed by pulse wave analysis

Valuable information about cardiovascular system can be derived from the shape of aortic pulse wave being the result of reciprocal interaction between heart and vasculature. Pressure profiles in ascending aorta were obtained from peripheral waveforms recorded non-invasively (SphygmoCor, AtCor Medical, Australia) before, during and after hemodialysis sessions performed after 3-day and 2-day interdialytic intervals in 35 anuric, prevalent hemodialysis patients. Fluid status was assessed by Body Composition Monitor (Fresenius Medical Care, Bad Homburg, Germany) and online hematocrit monitoring device (CritLine, HemaMetrics, Utah). Systolic pressure and ejection duration decreased during dialysis. Augmentation index remained stable at 30 ± 13% throughout hemodialysis session despite the decrease of augmented pressure and pulse height. Subendocardial viability ratio (SEVR) determined after 3-day and 2-day interdialytic intervals increased during the sessions by 43.8 ± 26.6% and 26.1 ± 25.4%, respectively. Hemodialysis performed after 3-day and 2-day interdialytic periods reduced significantly overhydration by 2.4 ± 1.0 L and 1.8 ± 1.2 L and blood volume by 16.3 ± 9.7% and 13.7 ± 8.9%, respectively. Intradialytic increase of SEVR correlated with ultrafiltration rate (R = 0.39, p-value < 0.01), reduction in overhydration (R = -0.57, p-value < 0.001) and blood volume drop (R = -0.38, p-value < 0.01). The strong correlation between the decrease of overhydration during hemodialysis and increase in SEVR confirmed that careful fluid management is crucial for proper cardiac function. Hemodialysis affected cardiovascular system with the parameters derived from pulse-wave-analysis (systolic and augmented pressures, pulse height, ejection duration, SEVR) being significantly different at the end of dialysis from those before the session. Combination of pulse-wave-analysis with the monitoring of overhydration provides a new insight into the impact of hemodialysis on cardiovascular system.

Vascular Dysfunction, Oxidative Stress, and Inflammation in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES

Both increased arterial stiffness and vascular endothelial dysfunction are evident in patients with autosomal dominant polycystic kidney disease, even early in the course of the disease when kidney function in preserved. Vascular dysfunction in autosomal dominant polycystic kidney disease is thought to be related to vascular oxidative stress and inflammation, but direct evidence is lacking.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We assessed carotid-femoral pulse-wave velocity (arterial stiffness) and brachial artery flow-mediated dilation (vascular endothelial function) in participants with early-stage autosomal dominant polycystic kidney disease (eGFR≥60 ml/min per 1.73 m2) and a history of controlled hypertension and in healthy controls. Brachial artery flow-mediated dilation was also assessed after infusion of ascorbic acid to inhibit vascular oxidative stress compared with saline. Vascular endothelial cells were collected from a peripheral vein to measure expression of proteins, and circulating markers were also assessed by ELISA or liquid chromatography-tandem mass spectrometry.

RESULTS

In total, 61 participants with autosomal dominant polycystic kidney disease (34±9 years old [mean±SD]) and 19 healthy controls (30±5 years old) were studied. Carotid-femoral pulse-wave velocity was higher in participants with autosomal dominant polycystic kidney disease compared with healthy controls (650±131 versus 562±81 cm/s; P=0.007). Brachial artery flow-mediated dilation was 8.2%±5.8% in participants with autosomal dominant polycystic kidney disease and 10.8%±4.7% in controls (P=0.08). Among participants with autosomal dominant polycystic kidney disease, flow-mediated dilation increased from 7.7%±4.5% to 9.4%±5.2% with ascorbic acid, a difference of 1.72 (95% confidence interval, 0.80 to 2.63), whereas in control participants, flow-mediated dilation decreased nonsignificantly from 10.8%±4.7% to 10.6%±5.4%, a difference of -0.20 (95% confidence interval, -1.24 to 0.84; P interaction =0.02). Endothelial cell protein expression of NF-κB was greater in participants with autosomal dominant polycystic kidney disease (0.48±0.12 versus 0.41±0.10 [intensity versus human umbilical vein endothelial cell control]; P=0.03). However, circulating oxidative stress markers and bioactive lipid mediators did not significantly differ according to the autosomal dominant polycystic kidney disease diagnosis.

CONCLUSIONS

These results provide support for the hypothesis that vascular oxidative stress and inflammation develop with autosomal dominant polycystic kidney disease.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_09_18_CJASNPodcast_18_10_.mp3.

Arterial stiffness in black African ancestry patients with chronic kidney disease living in Cameroon

Background

Increased aortic pulse wave velocity (PWV), a direct measure of arterial stiffness (AS) is an independent predictor of cardiovascular events (CVEs) in chronic kidney disease (CKD) patients. This study assessed the patterns of PWV among Cameroonian patients with CKD in whom that marker of early vascular aging has not been explored so far.

Methods

We enrolled 150 Black African patients (mean age: 52±15 years, 56.7% males) with CKD in a cross-sectional study conducted at Douala General Hospital, Douala, Cameroon. Sociodemographic, anthropometric and biologic variables, blood pressure (BP) and PWV were recorded in all participants. Estimated aortic PWV was measured using a Mobil-O-Graph automatic brachial oscillometric device.

Results

PWV increased with aging (P<0.0001), and PWV adjusted for age, sex, body mass index and mean arterial BP (MAP) was higher in non-dialysed (n=90) than in hemodialysed (n=60) patients, even in pre-dialysis: 8.5±2.0 vs. 7.9±1.4 m/s (P=0.026); and in post-dialysis: 8.5±2.0 vs. 7.8±1.5 m/s (P=0.008). The mean PWV of all study participants was 8.2±1.8 m/s, with 61.3% of patients having a PWV ≥8.2 m/s, indicative of subclinical damage to the aorta, which was more pronounced in non-dialysis (67.8%) than in hemodialysis (53.3%) patients (P=0.033). Multivariable analysis performed in all participants revealed that advanced age, MAP and tobacco use were independently associated with PWV (all P<0.05).

Conclusions

Our findings suggest increased AS in Cameroonian CKD non-dialyzed as compared to dialyzed patients. Slower PWV in patients on maintenance hemodialysis suggests improvement of aortic distensibility following dialysis. However, further large-scale studies are needed to confirm our findings and to improve understanding of the underlying mechanisms of arterial stiffening in black African ancestry patients with CKD.

Arterial stiffness may predict renal and cardiovascular prognosis in autosomal-dominant polycystic kidney disease

Background and aims

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common causes of end-stage renal disease (ESRD). The most important cause of death among ADPKD patients is cardiovascular (CV). The aim of this study was to examine the prognostic significance of arterial stiffness on CV and renal outcomes in ADPKD.

Methods

A total of 55 patients with ADPKD were examined. Pulse wave velocity was determined and stiffness index (SIDVP) was calculated. Combined primary endpoints (CV and renal) were major CV events (myocardial infarction, stroke, and CV intervention) as CV endpoints, and attaining of ESRD or start of renal replacement therapy as renal endpoints. Secondary endpoints were CV or renal endpoints separately.

Results

The mean age of those 55 ADPKD patients was 45 ± 12 years, 21 patients were male. The average value of the SIDVP was 11.11 ± 2.22 m/s. The patients were divided into two groups by the cutoff value of 11 m/s of SIDVP and then outcomes were analyzed. In the higher arterial stiffness group (SIDVP > 11 m/s), occurrence of combined primary endpoint (CV and renal) was significantly higher than in the group with more elastic arteries (p = 0.033). A statistically significant difference was found in the renal endpoints (p = 0.018), but not in the CV endpoints (p = 0.952) between the two groups.

Conclusions

Increased arterial stiffness predicts the onset of ESRD in ADPDK. Assessment of SIDVP appears to be a useful method for estimating the renal and CV prognosis in ADPKD.

Association of clinical and laboratory parameters with ambulatory arterial stiffness index in acromegaly patients

Objective

In this study, we determined the relationship between the ambulatory arterial stiffness index (AASI) and clinical and laboratory parameters in patients with acromegaly.

Methods

Sixty-five patients with acromegaly, who visited to Dicle University Medical Faculty Department of Endocrinology (33 females and 32 males), were included in this study. The study control group consisted of 65 subjects. Demographic and clinical data were recorded. Laboratory data (complete blood count, blood urea nitrogen, creatinine, electrolytes, albumin, lipid profile, growth hormone [GH], insulin-like growth factor-1, and the 75-g oral glucose tolerance test) performed over the last year were evaluated. The AASI was obtained from 24-hour ambulatory blood pressure monitoring records of all patients. This study was completed in 15 months from 2013 to 2015.

Results

Twelve patients (18.4%) had diabetes and 21 patients (32%) had hypertension. The mean AASI value was 0.41 ± 0.14. The mean AASI value in the control group was 0.25 ± 0.09. Growth hormone (GH) levels were positively correlated with the AASI values. AASI values tended to be higher in hypertensive subjects than that in normotensive individuals.

Conclusions

Our results show that the AASI value increased in patients with acromegaly, independent of the increase in blood pressure. The AASI was strongly dependent on the degree of the GH increase in patients with acromegaly and may have an important role predicting cardiovascular risk in patients with acromegaly.

Vascular dysfunction in children and young adults with autosomal dominant polycystic kidney disease

Background

Adults with autosomal dominant polycystic kidney disease (ADPKD) exhibit vascular dysfunction, as evidenced by impaired endothelium-dependent dilation (EDD) and stiffening of the large elastic arteries. However, it is unknown whether vascular dysfunction begins earlier in the course of ADPKD. The aim of the study was to assess EDD and arterial stiffness in children and young adults with ADPKD.

Methods

Fifteen children and young adults 6–22 years of age with ADPKD and normal renal function were prospectively recruited for participation in a cross-sectional study. Fifteen healthy controls were enrolled to match cases for age and sex. The primary outcomes were EDD, measured as brachial artery flow-mediated dilation (FMDBA), and arterial stiffness, measured as carotid-femoral pulse wave velocity (CFPWV).

Results

ADPKD cases were more likely to be taking an angiotensin-converting enzyme inhibitor, but otherwise did not differ from controls in clinical characteristics, including blood pressure. FMDBA was 25% lower in children and young adults with ADPKD (7.7 ± 0.9%, mean ± SE) when compared with matched controls (10.2 ± 0.8%) (P < 0.05). CFPWV was 14% higher in children and young adults with ADPKD (544 ± 23 cm/s) when compared with matched controls (478 ± 17 cm/s) (P < 0.05). Secondary measures of arterial stiffness, carotid augmentation index and carotid systolic blood pressure were also increased in cases when compared with controls (P < 0.05).

Conclusions

Impaired EDD and increased arterial stiffness, important independent predictors of future cardiovascular events and mortality, are evident very early in the course of ADPKD in the presence of normal kidney function. Novel interventions to reduce vascular dysfunction in children and young adults with ADPKD should be evaluated, as childhood and young adulthood may represent a critical therapeutic window to reduce future cardiovascular risk in patients with ADPKD.

Vascular access Localization Determines Regional Changes in Arterial Stiffness

Background

Vascular access (VA) dysfunction is a common cause of hospitalization in chronically hemodialyzed patients (CHP) limiting the improvement in health and has been largely studied in order to decrease the morbidity events that involves both the artery and the vein used in the construction of the fistula. In parallel, patients in end-stage renal failure show an increase in arterial stiffness.

Aim

The aims of this work were: (a) to evaluate arterial stiffness through pulse wave velocity (PWV) measurements in the carotid-brachial pathway where the arteriovenous fistulae (AVF) was constructed, and (b) to determine possible differences in arterial stiffness between the carotid-brachial pathway with and without VA.

Methods

PWV, clinical and biochemical parameters were measured in 38 CHP. PWV was obtained in the carotid-femoral, and in the left and right carotid-brachial pathway.

Results

Carotid-brachial PWV determination in upper limbs with AVF (10.07 ± 2.43 m/s) showed significantly lower values than those observed in the contra-lateral arm without VA (11.55 ± 2.27 m/s). Curiously, the PWV value observed in arms with an AVF was significantly lower in diabetic than in non-diabetic hemodialyzed patients (NDHP) (8.00 ± 2.86 m/s and 10.38 ± 2.33 m/s; respectively). Measurements of PWV in the carotid-femoral pathway in CHP showed a mean value of 14.09 ± 3.12 m/s. Carotid-femoral PWV in NDHP (14.06 ± 2.44 m/s) was significantly lower than that observed in the diabetic patients (16.87 ± 3.42 m/s).

Conclusions

Carotid-brachial PWV values obtained in the upper limbs, in which VAs were constructed, were significantly lower than that measured in intact arteries in the contra-lateral pathway in CHP.

Inflammation and Arterial Stiffness in Chronic Kidney Disease: Findings From the CRIC Study

BACKGROUND

Chronic kidney disease (CKD) and arterial stiffness are associated with increased cardiovascular morbidity and mortality. Inflammation is proposed to have a role in the development of arterial stiffness, and CKD is recognized as a proinflammatory state. Arterial stiffness is increased in CKD, and cross-sectional data has suggested a link between increased inflammatory markers in CKD and higher measures of arterial stiffness. However, no large scale investigations have examined the impact of inflammation on the progression of arterial stiffness in CKD.

METHODS

We performed baseline assessments of 5 inflammatory markers in 3,939 participants from the chronic renal insufficiency cohort (CRIC), along with serial measurements of arterial stiffness at 0, 2, and 4 years of follow-up.

RESULTS

A total of 2,933 participants completed each of the follow-up stiffness measures. In cross-sectional analysis at enrollment, significant associations with at least 2 measures of stiffness were observed for fibrinogen, interleukin-6, high-sensitivity C-reactive protein, proteinuria, and composite inflammation score after adjustment for confounders. In longitudinal analyses, there were few meaningful correlations between baseline levels of inflammation and changes in metrics of arterial stiffness over time.

CONCLUSION

In a large cohort of CKD participants, we observed multiple significant correlations between initial markers of inflammation and metrics of arterial stiffness, but baseline inflammation did not predict changes in arterial stiffness over time. While well-described biologic mechanisms provide the basis for our understanding of the cross-sectional results, continued efforts to design longitudinal studies are necessary to fully elucidate the relationship between chronic inflammation and arterial stiffening.

Arterial compliance in a group of normotensive and untreated hypertensive Cameroonian subjects in Yaounde

INTRODUCTION

Arterial compliance is an independent predictor of cardiovascular events. It decreases with age and this decrease is accelerated by hypertension. The objectives were to determine the arterial compliance in a group of normotensive and untreated hypertensive stage 1, 2 and 3 Cameroonian subjects.

METHODS

A cross-sectional study was conducted from August 2012 to February 2013 in Yaoundé. Our sample size was 88 participants. The PulsePen® device was used to determine cfPWV (carotid-femoral Pulse Wave Velocity) and central Augmentation Index % (AIx). Other measurements obtained were: blood pressure (BP), body mass index (BMI), fasting glycaemia, lipid profile and serum creatinine.

RESULTS

Our sample's mean age was 35.48 years and ranged from 20 to 60 years. The means of: cfPWV, SBP, DBP, Pulse Pressure (PP) and Heart Rate (HR) showed a statistically significant increase (p-value < 0.05) across the groups from normotensive to severely hypertensive patients. cfPWV was significantly correlated (p-value< 0.05) to: Age, Central SBP, Central DBP, Central PP, HR, BMI and central Augmentation index (AIx). Furthermore, cfPWV was significantly dependent on LVH (p-value <0.05).

CONCLUSION

This study suggests that arterial compliance decreases with increase severity of hypertension, indicating a higher risk of developing cardiovascular events in severely hypertensive patients.

Is There an Increased Arterial Stiffness in Patients with Primary Sjögren's Syndrome?

OBJECTIVE

Primary Sjögren's syndrome (pSS) is a common chronic autoimmune disease that primarily affects the salivary and lacrimal glands. Arterial stiffness is one of the earliest detectable manifestations of adverse structural and functional changes within the vessel wall. The aim of this study was to evaluate the relationship between arterial stiffness and pSS.

METHODS

In this study, 75 female patients with pSS who fulfilled the American European Consensus Criteria for Sjögren's syndrome, were included. A total of 68 age-, sex- and body mass index-matched subjects were recruited as the control population. Arterial stiffness was assessed by measurement of the carotid-femoral pulse wave velocity (PWV).

RESULTS

The mean age of the patients was 54.0±9.3 years and the median duration of the disease was 10 years. Compared with the control subjects, patients with pSS had a higher mean PWV (8.2±1.5 m/s vs. 7.5±1.4 m/s; p=0.01). Correlation analysis showed that the PWV was positively correlated with age, body mass index, serum cholesterol, low-density lipoprotein (LDL) and C-reactive protein levels, blood pressure, mean arterial pressure (MAP), pulse pressure and left ventricular mass index. A multiple linear regression analysis revealed that arterial stiffness was associated with age, MAP and LDL levels in pSS patients.

CONCLUSION

Although patients with pSS appear to have increased arterial stiffness, risk factors associated with arterial stiffness in these patients are similar to the general population. However, we cannot exclude the possibility that a higher PWV in pSS patients is caused, not by pSS itself, but by the use of steroids, hypertension and dyslipidemia.

Dynamics of circulating microparticles in chronic kidney disease and transplantation: Is it really reliable marker?

The deterioration of endothelial structure plays a very important role in the development of vascular diseases. It is believed that endothelial dysfunction starts in the early stage of kidney disease and is a risk factor of an unfavorable cardiovascular prognosis. Because a direct assessment of biological states in endothelial cells is not applicable, the measurement of endothelial microparticles (EMPs) detached from endothelium during activation or apoptosis is thought to be a marker of early vascular disease and endothelial dysfunction in children with chronic kidney disease (CKD). Few studies have shown increased circulating EMPs and its relationship with cardiovascular risk factors in patients with CKD. MPs contain membrane proteins and cytosolic material derived from the cell from which they originate. EMPs having CD144, CD 146, CD31⁺/CD41^-, CD51 and CD105 may be used to evaluate the vascular endothelial cell damage and determine asymptomatic patients who might be at higher risk of developing cardiovascular disease in CKD and renal transplant.

Clinical Significance of Pre-Transplant Arterial Stiffness and the Impact of Kidney Transplantation on Arterial Stiffness

Background

Arterial stiffness is closely associated with cardiovascular disease (CVD) in end stage renal disease (ESRD) patients. However, the clinical significance of pre-transplant arterial stiffness and the impact of kidney transplantation (KT) on arterial stiffness have not yet been determined.

Method

We measured the brachial-ankle pulse wave velocity (baPWV) before KT and one year after KT. We evaluated the potential utility of pre-transplant baPWV as a screening test to predict CVD. The impact of KT on progression of arterial stiffness was evaluated according to changes in baPWV after KT. The factors that influence the change of baPWV after KT were also examined.

Result

The mean value of pre-transplant baPWV was 1508 ± 300 cm/s in ESRD patients; 93.4% had a higher baPWV value than healthy controls. Pre-transplant baPWV was higher in patients with CVD than in those without CVD (1800 ± 440 vs. 1491 ± 265 cm/s, p<0.05), and was a strong predictive factor of CVD (OR 1.003, p<0.05). The optimal cut-off value of baPWV for the detection of CVD was 1591 cm/s, and this value was an independent predictor of CVD in KT recipients (OR 6.3, p<0.05). The post-transplant baPWV was significantly decreased compared to that of pre-transplant rates (1418 ± 235 vs. 1517 ± 293 cm/s, p<0.05), and progression of arterial stiffness was not observed in 86.9% patients. Logistic regression analysis revealed that higher body mass index and the degree of increase in calcium levels were independent risk factors that affected baPWV after KT.

Conclusions

Evaluation of arterial stiffness with baPWV is a useful screening test for predicting CVD after KT, and KT is effective in preventing the progression of arterial stiffness in ESRD patients.

Arterial Stiffness and Renal Replacement Therapy: A Controversial Topic

The increase of arterial stiffness has been to have a significant impact on predicting mortality in end-stage renal disease patients. Pulse wave velocity (PWV) is a noninvasive, reliable parameter of regional arterial stiffness that integrates the vascular geometry and arterial wall intrinsic elasticity and is capable of predicting cardiovascular mortality in this patient population. Nevertheless, reports on PWV in dialyzed patients are contradictory and sometimes inconsistent: some reports claim the arterial wall stiffness increases (i.e., PWV increase), others claim that it is reduced, and some even state that it augments in the aorta while it simultaneously decreases in the brachial artery pathway. The purpose of this study was to analyze the literature in which longitudinal or transversal studies were performed in hemodialysis and/or peritoneal dialysis patients, in order to characterize arterial stiffness and the responsiveness to renal replacement therapy.

A prospective observational study comparing a non-operator dependent automatic PWV analyser to pulse pressure, in assessing arterial stiffness in hemodialysis

Background

Chronic kidney disease (CKD) accelerates vascular stiffening related to age. Arterial stiffness may be evaluated measuring the carotid-femoral pulse wave velocity (PWV) or more simply, as recommended by KDOQI, monitoring pulse pressure (PP). Both correlate to survival and incidence of cardiovascular disease. PWV can also be estimated on the brachial artery using a Mobil-O-Graph; a non-operator dependent automatic device. The aim was to analyse whether, in a dialysis population, PWV obtained by Mobil-O-Graph (MogPWV) is more sensitive for vascular aging than PP.

Methods

A cohort of 143 patients from 4 dialysis units has been followed measuring MogPWV and PP every 3 to 6 months and compared to a control group with the same risk factors but an eGFR > 30 ml/min.

Results

MogPWV contrarily to PP did discriminate the dialysis population from the control group. The mean difference translated in age between the two populations was 8.4 years. The increase in MogPWV, as a function of age, was more rapid in the dialysis group. 13.3% of the dialysis patients but only 3.0% of the control group were outliers for MogPWV. The mortality rate (16 out of 143) was similar in outliers and inliers (7.4 and 8.0%/year). Stratifying patients according to MogPWV, a significant difference in survival was seen. A high parathormone (PTH) and to be dialysed for a hypertensive nephropathy were associated to a higher baseline MogPWV.

Conclusions

Assessing PWV on the brachial artery using a Mobil-O-Graph is a valid and simple alternative, which, in the dialysis population, is more sensitive for vascular aging than PP. As demonstrated in previous studies PWV correlates to mortality. Among specific CKD risk factors only PTH is associated with a higher baseline PWV.

Trial registration

ClinicalTrials.gov Identifier: NCT02327962.

Does Vascular Calcification Correlate with Pulse Wave Velocity in Hemodialysis Patients?

Vascular calcifications have been previously shown to be an independent predictor of mortality in dialysis patients and a similar association has been shown for arterial stiffness. Nonetheless, the relationship between vascular calcifications and pulse wave velocity (PWV) have so far been little explored. The goal of this study is to verify the correlation among vascular calcifications and rigidity of arterial wall in patients at dialysis start. Accordingly, we investigated the association between aortic PWV and coronary calcification measured by computed tomography (TC-score) in 105 adult incident hemodialysis patients. PWV resulted increased in patients with the higher TC-score values; indeed, at univariate analysis PWV directly correlated with age (p=0.016), presence of diabetes (p<0.0001), serum phosphorus (p=0.0066), C-reactive protein (CRP) (p=0.046), LDL-cholesterol (p=0.043), TC-score (p<0.0001), and inversely correlated with systolic blood pressure (p=0.036). At multivariate analysis, age, diabetes, serum phosphorus, CRP, LDL-cholesterol and vascular calcifications were determinants of arterial stiffening. Using the table “two for two”, we showed 6 false negative patients (high TC-score and low PWV) and 12 false positive patients (low TC-score and high PWV). The sensibility was 76% and the specificity 85%; the accuracy was 83%, the predictor positive value was 61% and the predictor negative value was 92%. Overall, a strong association between TC-score and PWV was seen.

Aortic pulse wave velocity in haemodialysis patients is associated with the prescription of active vitamin D analogues

BACKGROUND

Cardiovascular disease remains the most common cause of death for haemodialysis patients. In addition to traditional cardiovascular risk factors, haemodialysis patients have additional risk factors, including vascular calcification. Pulse wave velocity (PWV) is a measurement of arterial stiffness, and we wished to determine whether PWV is affected by different factors in haemodialysis patients compared to the general population.

METHODS

Aortic PWV was measured in 303 adult patients attending for routine outpatient dialysis.

RESULTS

303 patients, 63.4% male, mean age 68.5 ± 15.8 years, 47.5% diabetic with a body mass index of 25.8 ± 5.3 kg/m(2), were studied. Systolic blood pressure (SBP) was 148.7 ± 28.6 mmHg and diastolic 80.4 ± 15.3 mmHg. Aortic PWV was 9.73 ± 2.08 m/s, and was correlated with SBP (β 0.015, F 5.29, p = 0.023), log serum parathyroid hormone (PTH) (β 1.58, F 13.85, p < 0.001) and prescription of alfacalcidol (β -1.11, F 6.81, p = 0.010). 197 patients had corresponding ECHO cardiograms, and in this cohort PWV was associated with SBP (β 0.017, F 7.49, p = 0.006), log serum parathyroid hormone (β 0.85, F 5.99, p < 0.015) and prescription of alfacalcidol (β -0.8, F 4.18, p = 0.042), left ventricular mass index (LVMI) (β 0.01, F 11.4, p = 0.001), and log serum triglycerides (β 1.43, F 4.79, p = 0.03).

CONCLUSIONS

We found that PWV, a measurement of arterial stiffness, was associated with both traditional cardiovascular risk factors, including SBP and LVMI, but also non-traditional risk factors such as prescription of active vitamin D analogues, suggesting a potential link between vascular calcification and arterial stiffness in haemodialysis patients.

IgA nephropathy with early kidney disease is associated with increased arterial stiffness and renin-angiotensin system activity

BACKGROUND

IgA nephropathy is associated with increased cardiovascular risk, though whether this is due to loss of kidney function or proteinuria is unclear.

METHODS

For this study 10 normotensive IgA nephropathy subjects with early kidney disease (41±5 yrs, glomerular filtration rate (GFR) 87±9 ml/min, proteinuria 720±300 mg/d) and 10 gender- and blood pressure-matched healthy controls (36±1 yrs, estimated GFR 102±5 ml/min, proteinuria 70±6 mg/d) were studied in high-salt balance. Blood pressure and arterial stiffness, expressed as pulse wave velocity and aortic augmentation index, were measured at baseline and in response to 60 min of angiotensin II (AngII) infusion.

RESULTS

At baseline, IgA nephropathy subjects demonstrated similar pulse wave velocity (8.6±0.7 vs. 8.0±0.4 m/s, p=0.5) but increased aortic augmentation index (12.6±3.1 vs. 1.8±4%, p=0.04) and a trend towards increased circulating renin-angiotensin system (RAS) components (plasma renin activity, 0.55±0.18 vs. 0.21±0.05 ng/l/s, p=0.08; angiotensin II, 25±5 vs. 16±1 ng/l, p=0.08) compared with controls. However, despite similar baseline blood pressure values (p=0.8), IgA nephropathy was associated with reduced arterial sensitivity to AngII challenge (Δmean arterial pressure: 19±4 vs. 29±1 mm Hg, p=0.05; Δpulse wave velocity: -0.06±0.6 vs. 1.5±0.3 m/s, p=0.07) compared with controls, even after multivariate analysis.

CONCLUSION

Even in the setting of early kidney disease, IgA nephropathy is associated with increased arterial stiffness and decreased angiotensin II responsiveness, a marker of increased RAS activity.

Echo-Doppler assessment of the biophysical properties of the aorta in children with chronic kidney disease

Chronic kidney disease (CKD) is known to cause increased arterial stiffness, which is an important independent risk factor for adverse cardiovascular events. The purpose of this study was to assess the vascular properties of the aorta (AO) in a group of children with CKD using a noninvasive echocardiography (echo)-Doppler method. We studied 24 children with stages 2 through 5 CKD and 48 age-matched controls. Detailed echocardiographic assessment and echo-Doppler pulse wave velocity (PWV) was performed. Indices of arterial stiffness, including characteristic (Zc) and input (Zi) impedances, elastic pressure-strain modulus (Ep), and arterial wall stiffness index, were calculated. CKD patients underwent full nephrology assessment, and an iohexol glomerular filtration rate was performed, which allowed for accurate assignment of the CKD stage. CKD patients had greater median systolic blood pressure (114 vs. 110 mmHg; p < 0.04) and pulse pressure (51 vs. 40 mmHg; p < 0.001) compared with controls. PWV was similar between groups (358 vs. 344 cm s(-1); p = 0.759), whereas Zi (182 vs. 131 dyne s cm(-5); p < 0.001), Zc (146 vs. 138 dyne s cm(-5); p = 0.05), and Ep (280 vs. 230 mmHg; p < 0.02) were significantly greater in CKD than in controls. Although load-dependent measures of arterial stiffness were greater in non-dialysis dependent CKD patients, PWV was not increased compared with controls. This suggests that the increased arterial stiffness may not be permanent in these pediatric patients with kidney disease.

Membrane Bioincompatibility and Ultrafiltration Effects on Pulse Wave Analysis during Haemodialysis

Membrane bioincompatibility was demonstrated by successive white blood cell counts and C3a generation. Pulse wave analysis was obtained by applanation tonometry (SphygmoCor) in a sequential way: basal, after 30 minutes with nul ultrafiltration, and after a complete dialysis with ultrafiltration. At 15 minutes of haemodialysis, significant decrease in leukocyte count occurred: 6801 ± 1186 versus 4412 ± 1333 (P < 0.001), while C3a levels sharply increased from 427 ± 269 to 3501 ± 1638 ng/mL (P < 0.000). No changes were observed in augmentation index without ultrafiltration: 26.1 ± 11.1 versus 26.6 ± 12.4. Only aortic systolic blood pressure was lower at 15 minutes: 120.1 ± 17.7 versus 110.4 ± 25.8 mmHg (P = 0.009), in agreement with a reduction in brachial systolic blood pressure: 135.1 ± 18.1 versus 122.7 ± 27.4 mmHg (P = 0.01), without changes in aortic or brachial diastolic blood pressure. Important changes in pulse wave analysis were observed after a complete haemodialysis session: augmentation index 29.9 ± 10.1 versus 18.6 ± 15.0, aortic systolic blood pressure 139.8 ± 25.5 versus 119.4 ± 28.5 mmHg (P < 0.00), without changes in aortic diastolic blood pressure. In summary, haemodialysis with cellulose diacetate acutely induced a transient state of immunoactivation due to bioincompatibility, this phenomenon was nondetectable by pulse wave analysis. Complete haemodialysis session led to important changes in pulse wave analysis.

Association of arterial rigidity with incident kidney disease and kidney function decline: the Health ABC study

BACKGROUND AND OBJECTIVE

The association of large arterial rigidity and kidney function decline in longitudinal analyses is not well established. This study evaluated the association of aortic pulse wave velocity (aPWV) and pulse pressure (PP) with rapid kidney function decline and incident CKD in the Health, Aging and Body Composition study.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Participants were 2129 older adults with a baseline measurement of aPWV, PP, and cystatin C and at least one additional measurement of cystatin C, either at year 3 or year 10. Outcomes were rapid kidney function decline (estimated GFRcysC loss of >3 ml/min per 1.73 m(2) per year) and incident CKD (eGFRcysC < 60 ml/min per 1.73 m(2) in participants with baseline estimated GFR > 60 ml/min per 1.73 m(2)). Multivariate regression models were used to evaluate association of aPWV and PP with each outcome.

RESULTS

Mean (SD) baseline estimated GFRcysC was 79±29 ml/min per 1.73 m(2). Median follow-up duration was 8.9 years. In multivariable analyses, aPWV was not associated with rapid decline (odds ratio [OR], 95% confidence interval [CI] 1.16, 0.89-1.52) but was associated with incident CKD (incident rate ratio [IRR], 95% CI, 1.39, 1.09-1.77) and PP was associated with both rapid decline (OR, 95% CI 1.10, 1.04-1.16) and incident CKD (IRR, 95% CI, 1.06, 1.01-1.11).

CONCLUSIONS

Large arterial stiffness assessed by aPWV and pulsatility assessed by PP were associated with incident CKD among older adults. Pulsatility assessed by PP was associated with rapid kidney function decline and incident CKD. Future research should determine whether interventions targeting arterial rigidity will prevent CKD development and progression.

The contribution of thyroid dysfunction on cardiovascular disease in patients with chronic kidney disease

Accelerated atherosclerosis and arterial stiffness are the two leading causes of increased cardiovascular disease in patients with chronic kidney disease. Dysfunctional thyroid hormone metabolism has been suggested to play a role in atherosclerosis and arterial stiffness. Changes in cardiac contractility and output, myocardial oxygen demand, systemic and peripheral vascular resistance, blood pressure and lipid profile, increased inflammatory burden and endothelial dysfunction may be responsible for thyroid hormone-related cardiovascular disease. This article focuses on the mechanistic insights of this association and provides a concise review of the current literature.

Epicardial adipose tissue volume and cardiovascular disease in hemodialysis patients

OBJECTIVE

Epicardial adipose tissue (EAT) is proposed as a cardiovascular risk marker in non-uremic subjects. However, little is known about its role in patients with higher cardiovascular risk profile such as chronic kidney disease. The aim of this study was to investigate the relationship between EAT and several cardiovascular surrogate markers (coronary artery calcification (CAC), arterial stiffness and atherosclerosis) in patients on maintenance hemodialysis.

METHODS

A total of 191 prevalent hemodialysis patients were enrolled in this cross-sectional study. EAT and CAC scores (CACs) were determined by multi-slice computerized tomography, arterial stiffness by carotid-femoral pulse wave velocity (PWV), and carotid artery intima-media thickness (CA-IMT) by B-mode doppler ultrasonography.

RESULTS

Mean age was 59 ± 13 years and time on hemodialysis 75 ± 44 months. Twenty percent of the patients had diabetes. Mean EAT volume was 62.6 ± 26.8 cm(3)/m(2). Mean CA-IMT and PWV values increased across the EAT tertiles. EAT was correlated with age, female gender, body mass index, albumin and lipid parameters. Additionally, CA-IMT and PWV values were positively correlated with EAT. EAT volume was significantly higher in patients with CACs >10 compared to the patients with CACs ≤10. Despite the univariate associations between EAT and cardiovascular surrogate markers, only age, body mass index and total cholesterol levels were associated with EAT in adjusted models.

CONCLUSIONS

In prevalent hemodialysis patients, EAT is correlated with atherosclerosis, arterial stiffness and the presence of CAC. However, this correlation is not independent of other risk factors.

Stiffness parameter β as a predictor of the 4-year all-cause mortality of chronic hemodialysis patients

BACKGROUND

There is a lack of information on stiffness parameter β, an index of arterial stiffness, in hemodialysis (HD) patients. The aim of the present study was to investigate whether stiffness parameter β is predictive of the long-term mortality of chronic HD patients.

METHODS

We measured biochemical parameters and the stiffness parameter β of 80 patients on maintenance HD therapy and followed their course for 4 years, and we enrolled 70 of these 80 patients in the study. We divided the 70 patients into tertiles according to their stiffness parameter β values, and conducted multivariate analyses to examine the impact of the tertiles on 4-year mortality.

RESULTS

Older age and the presence of diabetes mellitus were found to be independently associated with higher stiffness parameter β values. Fifteen patients (21.4 %) died and 16 (22.9 %) experienced a new cardiovascular event during the follow-up period. The results of a Kaplan-Meier analysis revealed a significantly higher risk of all-cause mortality in the HD patients with highest stiffness parameter β values (p = 0.0106). According to the ROC curve, the cut-off level that yielded maximal sensitivity and specificity for predicting all-cause mortality was 10.1, and the sensitivity and specificity using the cut-off value were 69.2 and 70.2 %, respectively.

CONCLUSION

The results of this study suggest that stiffness parameter β is a predictor of all-cause mortality in chronic HD patients.

Successful kidney transplantation ameliorates arterial stiffness in end-stage renal disease patients

PURPOSE

Successful kidney transplantation (KTx) can ameliorate bodily damage caused by end-stage renal disease (ESRD). Arterial stiffness (AS) is one of the critical factors that shorten the survival of patients due to cardiovascular events. KTx may reduce AS as well; however, this has not been investigated well. We therefore conducted a retrospective study using noninvasive pulse wave velocity (PWV), which is a useful index of aortic damage.

PATIENTS AND METHODS

Fifty-eight consecutive kidney recipients (34 men, 24 women) were enrolled in this study. Mean age at transplantation was 40.5 ± 12.3 years and the dialysis period was 73.1 ± 95.8 months. The brachial-ankle PWV was measured preoperatively and 6 months postoperatively. First, we investigated the relationship between the PWV and the other parameters related to AS. Second, we studied the pre- to posttransplant change in PWV to evaluate the amelioration of AS after successful KTx.

RESULTS

PWV showed significant positive correlations with age, systolic blood pressure (BP), diastolic BP, and abdominal aortic calcification index. After successful KTx, PWV significantly decreased (P < .01). In addition, systolic and diastolic BP significantly decreased (P < .01 and P < .05, respectively).

CONCLUSION

Successful KTx ameliorates AS in ESRD patients. This might explain the improved cardiovascular prognosis of ESRD patients who undergo KTx.

Paraoxonase 1, atherosclerosis and arterial stiffness in renal patients

Atherosclerosis is an important contributor to increased cardiovascular burden in populations with and without renal disease. Paraoxonases (PON) are a group of enzymes that hydrolyse organophosphates. Recent evidence indicates a protective role for PON in patients with coronary artery disease and atherosclerosis. Although data are limited, the low enzyme activity found in patients with chronic kidney disease and renal transplants has been linked to atherosclerosis and arterial stiffness. In this paper, we review the emerging role of PON1 in the pathophysiology of atherosclerosis and arterial stiffness in patients with chronic kidney disease.