Prevalence of subclinical atheromatosis and associated risk factors in chronic kidney disease: the NEFRONA study

Matrix Gla protein polymorphism rs1800802 is associated with atheroma plaque progression and with cardiovascular events in a chronic kidney disease cohort

Background

Chronic kidney disease (CKD) is associated with increased atherosclerotic burden and higher risk for cardiovascular events (CVE). Atherosclerosis has a significant genetic component and, in CKD, it is influenced by mineral metabolism alterations. Therefore, genetic modifications of mineral metabolism-related proteins could affect atherosclerosis in CKD patients. In the present study we investigated the role of single nucleotide polymorphisms (SNPs) of the matrix gamma-carboxy glutamic acid protein (MGP) on atherosclerosis progression and CVE in a CKD cohort.

Methods

A total of 2187 CKD patients from the Observatorio Nacional de Aterosclerosis en Nefrologia (NEFRONA) study were genotyped for SNPs present in the matrix gamma-carboxy glutamic acid (Gla) protein (MGP) gene. Atheromatosis was detected by vascular ultrasound. Progression of atheromatosis, defined as an increase in territories with plaque, was assessed after 24 months. Patients were followed for 48 months for CVE. Association of SNPs with plaque progression was assessed by logistic regression and their capacity to predict CVE by Cox regression.

Results

Three SNPs of the MGP gene were analyzed. No association of the rs4236 or the rs1800801 SNPs was detected with any of the outcomes. However, patients homozygotes for the minor allele of the rs1800802 SNP showed higher adjusted risk for plaque progression [odds ratio 2.3 (95% confidence interval 1.06-4.9)] and higher risk of suffering a CVE [hazard ratio 2.16 (95% confidence interval 1.13-4.12)] compared with the rest of genotypes. No association of the SNP with total or dp-ucMGP levels was found in a subsample.

Conclusions

The rs1800802 polymorphism of MGP is associated with plaque progression and CVE in CKD patients.

Association between CKD-MBD and mortality in older patients with advanced CKD-results from the EQUAL study

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a common complication of CKD; it is associated with higher mortality in dialysis patients, while its impact in non-dialysis patients remains mostly unknown. We investigated the associations between parathyroid hormone (PTH), phosphate and calcium (and their interactions), and all-cause, cardiovascular (CV) and non-CV mortality in older non-dialysis patients with advanced CKD.

METHODS

We used data from the European Quality study, which includes patients aged ≥65 years with estimated glomerular filtration rate ≤20 mL/min/1.73 m2 from six European countries. Sequentially adjusted Cox models were used to assess the association between baseline and time-dependent CKD-MBD biomarkers and all-cause, CV and non-CV mortality. Effect modification between biomarkers was also assessed.

RESULTS

In 1294 patients, the prevalence of CKD-MBD at baseline was 94%. Both PTH [adjusted hazard ratio (aHR) 1.12, 95% confidence interval (CI) 1.03-1.23, P = .01] and phosphate (aHR 1.35, 95% CI 1.00-1.84, P = .05), but not calcium (aHR 1.11, 95% CI 0.57-2.17, P = .76), were associated with all-cause mortality. Calcium was not independently associated with mortality, but modified the effect of phosphate, with the highest mortality risk found in patients with both hypercalcemia and hyperphosphatemia. PTH level was associated with CV mortality, but not with non-CV mortality, whereas phosphate was associated with both CV and non-CV mortality in most models.

CONCLUSIONS

CKD-MBD is very common in older non-dialysis patients with advanced CKD. PTH and phosphate are independently associated with all-cause mortality in this population. While PTH level is only associated with CV mortality, phosphate seems to be associated with both CV and non-CV mortality.

B- and T-lymphocyte attenuator could be a new player in accelerated atherosclerosis associated with chronic kidney disease

BACKGROUND

In chronic kidney disease (CKD), cardiovascular morbi-mortality is higher than in general population. Atherosclerotic cardiovascular disease is accelerated in CKD, but specific CKD-related risk factors for atherosclerosis are unknown.

METHODS

CKD patients from the NEFRONA study were used. We performed mRNA array from blood of patients free from atheroma plaque at baseline, with (n=10) and without (n=10) de novo atherosclerotic plaque development 2 years later. Selected mRNA candidates were validated in a bigger sample (n=148). Validated candidates were investigated in vivo in an experimental model of CKD-accelerated atherosclerosis, and in vitro in murine macrophages.

RESULTS

mRNA array analysis showed 92 up-regulated and 67 down-regulated mRNAs in samples from CKD patients with de novo plaque development. The functional analysis pointed to a paramount role of the immune response. The validation in a bigger sample confirmed that B- and T-lymphocyte co-inhibitory molecule (BTLA) down-regulation was associated with de novo plaque presence after 2 years. However, BTLA down-regulation was not found to be associated with atherosclerotic progression in patients with plaque already present at baseline. In a model of CKD-accelerated atherosclerosis, mRNA and protein expression levels of BTLA were significantly decreased in blood samples and atheroma plaques. Plaques from animals with CKD were bigger, had more infiltration of inflammatory cells, higher expression of IL6 and IL17 and less presence of collagen than plaques from control animals. Incubation of macrophages with rat uremic serum decreased BTLA expression.

CONCLUSIONS

BTLA could be a potential biomarker or therapeutic target for atherosclerosis incidence in CKD patients.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Correlation between Coronary Artery Disease with Other Arterial Systems: Similar, Albeit Separate, Underlying Pathophysiologic Mechanisms

Atherosclerosis is a multifactorial systemic disease that affects the entire arterial tree, although some areas are more prone to lipid deposits than others. Moreover, the histopathological composition of the plaques differs, and the clinical manifestations are also different, depending on the location and structure of the atherosclerotic plaque. Some arterial systems are correlated with each other more than in that they simply share a common atherosclerotic risk. The aim of this perspective review is to discuss this heterogeneity of atherosclerotic impairment in different arterial districts and to investigate the current evidence that resulted from studies of the topographical interrelations of atherosclerosis.

Endothelial Cell Dysfunction and Increased Cardiovascular Risk in Patients With Chronic Kidney Disease

The endothelium is considered to be the gatekeeper of the vessel wall, maintaining and regulating vascular integrity. In patients with chronic kidney disease, protective endothelial cell functions are impaired due to the proinflammatory, prothrombotic and uremic environment caused by the decline in kidney function, adding to the increase in cardiovascular complications in this vulnerable patient population. In this review, we discuss endothelial cell functioning in healthy conditions and the contribution of endothelial cell dysfunction to cardiovascular disease. Further, we summarize the phenotypic changes of the endothelium in chronic kidney disease patients and the relation of endothelial cell dysfunction to cardiovascular risk in chronic kidney disease. We also review the mechanisms that underlie endothelial changes in chronic kidney disease and consider potential pharmacological interventions that can ameliorate endothelial health.

Clinical Factors Associated with Arterial Stiffness in Chronic Kidney Disease

BACKGROUND

Arterial stiffness influences the prognosis of patients with end-stage kidney disease; however, the factors that promote arterial stiffness in chronic kidney disease (CKD) patients remain unknown. We aimed to explore the clinical factors associated with arterial stiffness in CKD.

METHODS

Between September 2017 and September 2022, all CKD patients treated at the Department of Nephrology, General Hospital of the Chinese People's Liberation Army, excluding dialysis patients, were screened and their medical records within the last month were collected. Arterial stiffness was measured by the augmentation index (AIx). The correlative clinical factors with arterial stiffness were explored in different linear regression models.

RESULTS

559 patients were included in the study. AIx@75 increased as the deterioration of CKDG1-CKDG5, with values of 1 (-9, 11), 5.5 (-4, 13.25), 9 (0, 16), 12 (1.5, 23.5), and 22 (13, 28), respectively (Z = 63.03, p < 0.001). Multivariate linear regression analysis showed that AIx@75 was positively associated with female sex (β = 8.926, 95% confidence interval (CI) 6.291, 11.562, p < 0.001), age (β = 0. 485, 95% CI 0.39, 0.58, p < 0.001), mean arterial pressure (MAP) (β = 0.255, 95% CI 0.159, 0.35, p < 0.001), and was negatively associated with ACEI/ARB (β = -4.466, 95% CI -6.963, -1.969, p < 0.001) and glucocorticoid (β = -3.163, 95% CI -6.143, -0.183, p = 0.038). Smoking, eGFR, hemoglobin, and cause of disease were associated with AIx@75 in multivariate linear regression models when considering factors partly.

CONCLUSIONS

Female, age, smoking, MAP, eGFR, cause of disease, ACEI/ARB, and glucocorticoid were found to be associated with atherosclerosis in CKD patients.

Effects of Normal Reference Range of Phosphorus and Corresponding PTH on Endothelial Function in CKD Patients

Introduction

Endothelial dysfunction commonly occurs in chronic kidney disease (CKD) patients and increases the risk for cardiovascular disease. Among CKD patients, biomarkers involved in the pathogenesis of CKD-mineral bone disorder (CKD-MBD), such as phosphorus, parathyroid hormone, and fibroblast growth factor 23, are associated with endothelial dysfunction. We investigated whether these biomarkers induce endothelial dysfunction in CKD patients with normal phosphorus levels.

Methods

This cross-sectional study examined CKD patients with normal phosphorus levels; patients with an estimated glomerular filtration rate (eGFR) &lt;15 or who were under dialysis were excluded. Iontophoresis with laser doppler flowmetry (ILDF) and peripheral arterial tonometry were performed to assess endothelial function in 85 patients. Pearson's correlation coefficient, multiple regression, and mediation analyses were performed to examine the association between CKD-MBD biomarkers and endothelial dysfunction.

Results

Endothelial dysfunction was observed in all subjects with a low response to ILDF and 27% of subjects according to peripheral arterial tonometry. Acetylcholine (Ach)-induced ILDF was significantly associated with eGFR (r = 0.22, P = 0.04), intact parathyroid hormone (iPTH; r = −0.46, P &lt; 0.01), and VCAM-1 (r = −0.36, P &lt; 0.01). The reactive hyperemia index (RHI) was significantly related to phosphorus levels (r = 0.32, P &lt; 0.01) and iPTH (r = −0.39, P = 0.02). After adjusting for eGFR, iPTH and VCAM-1 remained independent factors for predicting endothelial dysfunction measured using Ach-induced ILDF. In addition, iPTH and phosphorus levels were independent predictors for endothelial dysfunction measured using RHI in the eGFR-adjusted model. Mediation analyses showed that the individual indirect effects of iPTH were significantly affected ILDF and RHI.

Conclusion

Serum levels of phosphorus and iPTH are associated with endothelial dysfunction, even in CKD patients with normal phosphorus levels.

Albuminuria but not low eGFR is closely associated with atherosclerosis in patients with type 2 diabetes: an observational study

BACKGROUND

There is still controversy regarding the associations of urinary albumin excretion (UAE) and estimated glomerular filtration rate (eGFR) with atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Therefore, it is necessary to explore the correlation between them in T2DM patients.

METHODS

We conducted a survey involving 2565 T2DM patients from a single center. The study cohort was classified into three groups based on the levels of albuminuria: normal UAE (UAE < 30 mg/24 h), moderate UAE (UAE between 30 and 299 mg/24 h) and high UAE (UAE ≥ 300 mg/24 h). Additionally, the patients were divided into three separate groups according to eGFR levels, including low eGFR (eGFR < 60 ml/min/1.73 m²), intermediate eGFR (eGFR 60-89 ml/min/1.73 m²) and normal eGFR (eGFR ≥ 90 ml/min/1.73 m²) groups. Atherosclerotic lesions were compared among the three UAE and eGFR groups. Regression analyses were used to assess the associations of atherosclerotic lesions with UAE and eGFR in T2DM.

RESULTS

After controlling for age, sex and diabetes duration, the prevalence of atherosclerotic plaque and stenosis were significantly increased from the normal to high UAE groups (plaque: 72.2%, 78.6% and 87.3%, respectively, p = 0.016 for trend; stenosis: 14.0%, 25.5% and 37.3%, respectively, p < 0.001 for trend). Likewise, the values of carotid intima-media thickness (CIMT) and femoral intima-media thickness (FIMT) were also obviously increased from the normal to high UAE groups (CIMT: p < 0.001 for trend; FIMT: p = 0.001 for trend). Conversely, only the FIMT value was clearly increased from the low to normal eGFR groups (p = 0.001 for trend). Fully adjusted regression analyses revealed that UAE was closely associated with the presence of atherosclerotic plaque (OR 1.20, 95% CI 1.03-1.40, p = 0.020) and stenosis (OR 1.17, 95% CI 1.01-1.35, p = 0.036), and with the values of CIMT (β 0.05, 95% CI 0.01-0.10, p = 0.029) and FIMT (β 0.07, 95% CI 0.03-0.11, p = 0.001) in T2DM patients. However, there was no significant association between eGFR levels and atherosclerotic lesions in T2DM after adjustment for multiple confounding factors.

CONCLUSIONS

Overall, albuminuria rather than low eGFR is closely associated with atherosclerotic lesions in T2DM patients. Albuminuria is an independent risk factor for carotid and femoral atherosclerotic lesions in T2DM. Therefore, albuminuria may be a potential early marker to predict the development of atherosclerosis in patients with T2DM.

Is serum Osteopontin a predictor of carotid atherosclerosis severity among prevalent hemodialysis patients?

BACKGROUND AND AIM

Chronic hemodialysis (HD) patients are among the highest population risk for accelerated atherosclerosis. Osteopontin (OPN) is a multifunctional protein that is increased in chronic kidney disease that may play a role in vascular remodelling and intimal proliferation.

AIM

To assess the relation between OPN levels and severity of carotid atherosclerosis among prevalent HD patients.

METHODS

Eighty chronic HD patients underwent serum OPN levels assessment and were further classified into 3 subgroups according to the OPN tertiles' levels; sub-group 1 (lower tertile) subgroup 2 (middle tertile) and sub-group 3 (upper tertile), together with the carotid duplex and Transthoracic Doppler Echocardiography examination.

RESULTS

The mean carotid intima-media thickness (CIMT) was 0.89±0.14mm. Out of the studied group, 50 (62.5%) patients had atheromatous plaques and 15 patients (18.8%). had significant stenosis. The 3rd group with the upper OPN tertile (78-270ng/dl) had the highest incidence of atherosclerosis. A significant correlation between the OPN levels and the CIMT (r=0.533, p=0.001). OPN values detect atherosclerosis with diagnostic sensitivity of 70%, specificity of 69%, positive predictive value (PPV) 73%, negative predictive value (NPV) 65% with area under the curve (AUC) 0.804 (95% CI: 0.711-0.897). Serum OPN detect carotid stenosis with sensitivity of 66%, specificity of 81%, PPV 45%, NPV 91% with AUC=0.769 and detect the presence of carotid atheroma with sensitivity 70%, specificity 66.67%, PPV 77.8%, NPV 57.1% and AUC=0.767 (p-value<0.001). Moreover, serum levels of OPN were significantly positively correlated with grade of diastolic dysfunction (r=0.312, p=0.005), E/A ratio (r=0.293, p=0.008) and inversely correlated with left ventricular ejection fraction (r=-0.304, p=0.006).

CONCLUSIONS

Serum Osteopontin is of clinical value as a predictor biomarker of the severity of carotid atherosclerosis, presence of atheroma and carotid stenosis with high diagnostic sensitivity and specificity in chronic hemodialysis patients. Increased Osteopontin level is associated with left ventricular diastolic and systolic dysfunction in those patients.

Advanced lipoprotein parameters could better explain atheromatosis in non-diabetic chronic kidney disease patients

Background

Chronic kidney disease (CKD) patients have a high burden of atheromatous cardiovascular disease (ASCVD) not fully explained by traditional lipid parameters. Lipoprotein composition and subclass particle number information could improve ASCVD risk assessment. The objective of this study is to investigate the association of advanced lipoprotein parameters with the risk of atheromatosis in a subpopulation of the NEFRONA study.

Methods

This was a cross-sectional study in 395 non-diabetic individuals (209 CKD and 186 non-diabetic and non-CKD) without statin therapy. Vascular ultrasound examination assessing 10 territories was combined with advanced lipoprotein testing performed by nuclear magnetic resonance spectroscopy. Logistic regression was used to estimate adjusted odds ratios (ORs) per 1 standard deviation increment.

Results

Atheromatosis was more prevalent in CKD patients (33.9% versus 64.6%). After adjusting for age, gender, smoking habit and CKD stage, the amount of triglycerides (TGs) within low-density lipoprotein (LDL) lipoproteins was independently and positively associated with atheromatosis [OR 1.33; 95% confidence interval (CI) 1.03–1.74; P = 0.03]. Similarly, total and medium LDL particles (LDL-Ps) showed a positive association (OR 1.29; 95% CI 1.00–1.68; P = 0.05 and OR 1.34; 95% CI 1.04–1.75; P = 0.03, respectively). TG-loaded medium LDL-Ps were higher in CKD patients compared with controls and showed an adjusted OR of 1.40 (95% CI 1.09–1.82; P = 0.01) in non-diabetic patients (CKD and non-CKD individuals). In contrast, non-diabetic CKD patients showed a similar coefficient but the significance was lost (OR 1.2; 95% CI 0.8–1.7; P = 0.359).

Conclusions

Non-diabetic CKD patients showed a higher amount of TG-loaded medium LDL-Ps compared with controls. These particles were independently associated with atheromatosis in non-diabetic patients.

Uremic serum damages endothelium by provoking excessive neutrophil extracellular trap formation

Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD). Endothelial cell (EC) dysfunction is a key CKD-specific risk factor; however, the mechanisms by which uremia harms the endothelium are still unclear. We report a role for excessive neutrophil extracellular trap (NET) formation induced by uremic serum on EC injury. Level of plasma nucleosome and myeloperoxidase-DNA, established in vivo markers of NETs, as well as intracellular adhesion molecule (ICAM)-1 were measured in hemodialysis (HD) patients and healthy volunteers (HV) and their prognostic role evaluated. For in vitro studies, HV-derived neutrophils and differentiated HL-60 cells by retinoic acid were used to determine the effect of uremic serum-induced NETs on human umbilical vein EC (HUVEC). The level of in vivo NETs was significantly higher in incident HD patients compared to HV, and these markers were strongly associated with ICAM-1. Specifically, nucleosome and ICAM-1 levels were independent predictors of a composite endpoint, all-cause mortality, or vascular access failure. In vitro, HD-derived uremic serum significantly increased NET formation both in dHL-60 and isolated neutrophils compared to control serum, and these NETs decreased EC viability and induced their apoptosis. In addition, the level of ICAM-1, E-selectin and von Willebrand factor in HUVEC supernatant was significantly increased by uremic serum-induced NETs compared to control serum-induced NETs. Dysregulated neutrophil activities in the uremic milieu may play a key role in vascular inflammatory responses. The high mortality and CVD rates in ESRD may be explained in part by excessive NET formation leading to EC damage and dysfunction.

Klotho as a biomarker of subclinical atherosclerosis in patients with moderate to severe chronic kidney disease

Chronic kidney disease (CKD) has been associated with a higher risk of cardiovascular disease (CVD). CKD patients present a decrease in the levels of the protein Klotho that accompanies the decrease in kidney function. This protein has been related to protective effects against CVD. However, it is unclear whether circulating Klotho, and its expression in peripheral blood cells (PBCs) are also associated with subclinical atherosclerosis in CKD. The present study aimed to study the relationship between Klotho and subclinical atherosclerosis in a population of patients with moderate to severe CKD. We determined the serum levels and gene expression in PBCs levels of Klotho and three inflammatory cytokines in 103 patients with CKD and investigated their relationship with two surrogate markers of subclinical atherosclerotis: ankle-brachial index (ABI) and carotid intima-media thickness (CIMT). Patients with subclinical atherosclerosis presented lower serum and PBCs expression levels of Klotho. Both variables were associated with the presence of subclinical atherosclerosis, being directly related with ABI and inversely with CIMT (P < 0.0001 for both). Multiple regression analysis demonstrated that both variables were significant determinants for ABI (adjusted R² = 0.511, P < 0.0001) and CIMT (adjusted R² = 0.445, P < 0.0001), independently of traditional and emergent cardiovascular risk factors. Moreover, both constituted protective factors against subclinical atherosclerosis [OR: 0.993 (P = 0.002) and 0.231 (P = 0.025), respectively]. Receiver operating characteristic analysis pointed to the utility of serum Klotho (area under the curve [AUC]: 0.817, 95% CI: 0.736-0.898, P < 0.001) and its gene expression in PBCs (AUC: 0.742, 95% CI: 0.647-0.836, P < 0.001) to distinguish subclinical atherosclerosis. The reductions in serum and PBCs expression levels of Klotho in CKD patients are independently associated with the presence of for subclinical atherosclerosis. Further research exploring whether therapeutic approaches to maintain or elevate Klotho could reduce the impact of CVD in CKD patients is warranted.

Association between chronic kidney disease and new-onset dyslipidemia: The Japan Specific Health Checkups (J-SHC) study

BACKGROUND AND AIMS

Dyslipidemias are common among patients with chronic kidney disease (CKD) and are a major risk factor for cardiovascular disease. This study aimed to investigate the association between early-stage CKD and new-onset dyslipidemia for each lipid profile.

METHODS

This nationwide longitudinal study included data from the Japan Specific Health Checkups (J-SHC) Study. New-onset dyslipidemia was indicated by hypertriglyceridemia (High-TG; ≥150 mg/dL), hyper-LDL cholesterolemia (High-LDL-C; ≥140 mg/dL), or hypo-HDL chelesterolemia (Low-HDL-C; <40 mg/dL) levels according to the guideline of Japan Atherosclerosis Society, or High-TG/HDL-C ratio (≥3.5) which was a good predictor of atherosclerosis. The incidence of new-onset dyslipidemia was compared between participants with and without CKD. Survival curves were used to analyze the incidence of each dyslipidemia.

RESULTS

Of 289,462 participants with a median follow-up period of 3 years, the incidence of High-TG, High-LDL-C, Low-HDL-C, and High-TG/HDL-C ratios were 64.4/1000 person-years, 83.1/1000 person-years, 14.5/1000 person-years, and 39.6/1000 person-years, respectively. The adjusted hazard ratios (95% confidence intervals) for High-TG, High-LDL-C, Low-HDL-C, and High-TG/HDL-C ratio were 1.09 (1.05-1.13), 0.99 (0.95-1.04), 1.12 (1.05-1.18), and 1.14 (1.09-1.18), respectively, in CKD participants as compared to non-CKD participants. Decreased eGFR and presence of proteinuria were independently associated with higher risks for new-onset of High-TG, Low-HDL-C, and High-TG/HDL-C ratios.

CONCLUSIONS

CKD was associated with a higher risk of new-onset High-TG, Low-HDL-C, and High-TG/HDL-C ratios, but not High-LDL-C, in the general population. These CKD-specific lipid abnormalities may explain the residual risk for CKD-related cardiovascular disease.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

Independent effects of secondary hyperparathyroidism and hyperphosphatemia on chronic kidney disease progression and cardiovascular events: an analysis from the NEFRONA cohort

BACKGROUND

Secondary hyperparathyroidism (SHPT) is a complication of chronic kidney disease (CKD), and it is associated with changes in calcium and phosphate. These related changes have been associated with increased cardiovascular mortality and CKD progression. It is not clear whether negative outcomes linked to SHPT are confounded by such factors. The present study was designed to assess the possible independent effects of SHPT (defined as patients with excessive PTH levels or on treatment with PTH reducing agents) on the risk of CKD progression and CVE incidence in CKD patients, as well as whether hypercalcemia and/or hyperphosphatemia act as effect modifiers.

METHODS

The study enrolled 2445 CKD patients without previous CVE from the NEFRONA cohort (950 stage 3, 612 stage 4, 195 stage 5 and 688 on Dialysis). Multivariate logistic and Fine and Gray regression analysis were used to determine the risk of patients of suffering CKD progression or a CVE.

RESULTS

Prevalence of SHPT in the whole cohort was 65.6% (CKD 3 54.7%; CKD 4 74.7%; CKD 5 71.4%; Dialysis 68.6%). After 2-years, 301 patients presented CKD progression. During 4-years follow-up, 203 CVE were registered. Patients with SHPT showed a higher adjusted risk for CKD progression and CVE. Furthermore, hyperphosphatemia was shown to be an independent risk factor in both outcomes and did not modify SHPT effect. No significant interactions were detected between the presence of SHPT and hypercalcemia or hyperphosphatemia.

CONCLUSIONS

We conclude that SHPT and hyperphosphatemia are independently associated with CKD progression and the incidence of CVE in CKD patients.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

The need for a cardionephrology subspecialty

Chronic kidney disease (CKD) has structural and functional repercussions for the cardiovascular system that facilitate the development of cardiovascular disease (CVD). In fact, cardiovascular complications are frequent in the CKD population and thus cause a great clinical, public health and economic burden. Despite this challenge, the prevention and management of cardiovascular complications is one among several aspects of CKD that meets the criteria of an unmet medical need. This probably has to do with the misperception by the nephrologist of the global relevance of CVD in the CKD patient which, in turn, may be due to insufficient cardiovascular training during nephrology specialization. Therefore a change in approach is necessary to understand CKD as a disease in which the manifestations and complications related to CVD become so frequent and important that they require dedicated multidisciplinary clinical management. From this perspective, it makes sense to consider training in the subspecialty of cardionephrology to provide adequate cardiovascular care for CKD patients by the nephrologist. In addition, the cardionephrology subspecialist would be better able to interact with other specialists in multidisciplinary care settings created to achieve a deeper understanding and more effective clinical handling of the interactions between CKD and CVD.

Optimal timing of coronary angiograms for patients with chronic kidney disease: association between the duration of kidney dysfunction and SYNTAX scores

Background

Chronic kidney disease (CKD) is associated with an increased risk of the progression of coronary artery disease (CAD). However, there are few data on the relationship between CAD severity and the duration of CKD. This study assessed the predictive value of the duration of kidney dysfunction in CKD patients with CAD severity.

Methods

In 145 patients (63.4% male, n = 92; mean age, 68.8 ± 12.8 years) with CKD, severity of CAD was assessed by coronary angiography and quantified by SYNTAX scores, and duration of kidney dysfunction was either assessed by checking historical biochemical parameters of individuals or was based on enquiries.

Results

Patients with high SYNTAX scores (≥ 22) had a greater prevalence of cardiovascular risk factors including age, gender, history of heart failure and smoking. In CKD patients, SYNTAX scores were positively correlated to duration of CKD and serum uric acid (UA), and negatively correlated to high-density lipoprotein-cholesterol (HDL-C) and ApoA1 levels. Univariate binary logistic regression and multivariate logistic analyses showed that SYNTAX scores correlated significantly with CKD duration, UA, and HDL-C. Receiver-operating characteristic analysis was used to explore a time point when coronary angiography application was economical and effective and yielded a Youden index of 6.5 years.

Conclusions

Together, our results demonstrated that the duration of kidney dysfunction was an independent correlate of the severity of CAD in patients with CKD. Our findings suggest that coronary angiography should be considered for CKD patients with renal insufficiency having lasted for more than 6.5 years.

Antiplatelet therapy for the prevention of atherosclerosis in chronic kidney disease (ALTAS-CKD) patients: study protocol for a randomized clinical trial

BACKGROUND

Cardiovascular disease (CVD) is the most common complication and the leading cause of death in patients with chronic kidney disease (CKD). Accelerated atherosclerosis is a pathophysiological process that is vital to the occurrence of cardiovascular complications associated with CKD. Abnormal platelet activation is not only the leading cause of atherosclerosis but also plays a critical role in the occurrence of thrombotic events. Currently, antiplatelet drugs are commonly used as a secondary prevention strategy for high blood pressure, obesity, diabetes, and ischemic heart disease and can reduce the risk of CVD in the susceptible population. However, the benefits and evidence of using antiplatelet agents in patients with CKD remain controversial. This study aimed to determine whether antiplatelet therapy can safely prevent atherosclerosis in patients with CKD in the primary care setting.

METHODS/DESIGN

The ALTAS-CKD study is a multicenter, prospective, randomized, double-blind, placebo-controlled trial of 554 adult patients with stage 3-5 non-dialysis-dependent CKD recruited from 10 territory medical centers in China. A secured web-based computer randomization system will be used to administer aspirin 100 mg once daily or a matching inactive placebo for 36 months. The primary endpoint will be the occurrence of atherosclerosis, as measured by carotid ultrasonography. The secondary endpoints will be combined cardiovascular events, all-cause mortality, and 50% decrease in the estimated glomerular filtration rate. TRIAL REGISTRATION {2A}: Current controlled trials number: ChiCTR1900021393 . Registered on 18 February 2019.

Association of a single nucleotide polymorphism combination pattern of the Klotho gene with non-cardiovascular death in patients with chronic kidney disease

Background

Chronic kidney disease (CKD) is associated with an elevated risk of all-cause mortality, with cardiovascular death being extensively investigated. However, non-cardiovascular mortality represents the biggest percentage, showing an evident increase in recent years. Klotho is a gene highly expressed in the kidney, with a clear influence on lifespan. Low levels of Klotho have been linked to CKD progression and adverse outcomes. Single nucleotide polymorphisms (SNPs) of the Klotho gene have been associated with several diseases, but studies investigating the association of Klotho SNPs with non-cardiovascular death in CKD populations are lacking.

Methods

The main aim of this study was to assess whether 11 Klotho SNPs were associated with non-cardiovascular death in a subpopulation of the National Observatory of Atherosclerosis in Nephrology (NEFRONA) study (n = 2185 CKD patients).

Results

After 48 months of follow-up, 62 cardiovascular deaths and 108 non-cardiovascular deaths were recorded. We identified a high non-cardiovascular death risk combination of SNPs corresponding to individuals carrying the most frequent allele (G) at rs562020, the rare allele (C) at rs2283368 and homozygotes for the rare allele (G) at rs2320762 (rs562020 GG/AG + rs2283368 CC/CT + rs2320762 GG). Among the patients with the three SNPs genotyped (n = 1016), 75 (7.4%) showed this combination. Furthermore, 95 (9.3%) patients showed a low-risk combination carrying all the opposite genotypes (rs562020 AA + rs2283368 TT + rs2320762 GT/TT). All the other combinations [n = 846 (83.3%)] were considered as normal risk. Using competing risk regression analysis, we confirmed that the proposed combinations are independently associated with a higher {hazard ratio [HR] 3.28 [confidence interval (CI) 1.51–7.12]} and lower [HR 6 × 10⁻⁶ (95% CI 3.3 × 10⁻⁷–1.1 × 10⁻⁵)] risk of suffering a non-cardiovascular death in the CKD population of the NEFRONA cohort compared with patients with the normal-risk combination.

Conclusions

Determination of three SNPs of the Klotho gene could help in the prediction of non-cardiovascular death in CKD.

Magnesium Levels Modify the Effect of Lipid Parameters on Carotid Intima Media Thickness

Classical risk factors of atherosclerosis in the general population show paradoxical effects in chronic kidney disease (CKD) patients. Thus, low low-density lipoprotein (LDL) cholesterol levels have been associated with worse cardiovascular outcomes. Magnesium (Mg) is a divalent cation whose homeostasis is altered in CKD. Furthermore, Mg levels have been associated with cardiovascular health. The present study aims to understand the relationships of Mg and lipid parameters with atherosclerosis in CKD. In this analysis, 1754 participants from the Observatorio Nacional de Atherosclerosis en Nefrologia (NEFRONA) cohort were included. Carotid intima media thickness (cIMT) was determined in six arterial territories, and associated factors were investigated by linear regression. cIMT correlated positively with being male, Caucasian, a smoker, diabetic, hypertensive, dyslipidemic and with increased age, BMI, and triglyceride levels, and negatively with levels of HDL cholesterol. First-order interactions in linear regression analysis showed that Mg was an effect modifier on the influence of lipidic parameters. Thus, cIMT predicted values were higher when triglycerides or LDL levels were high and Mg levels were low. On the contrary, when Mg levels were high, this effect disappeared. In conclusion, Mg acts as an effect modifier between lipidic parameters and atherosclerotic cardiovascular disease. Therefore, Mg levels, together with lipidic parameters, should be taken into account when assessing atherosclerotic risk.

TRAF3 Modulation: Novel Mechanism for the Anti-inflammatory Effects of the Vitamin D Receptor Agonist Paricalcitol in Renal Disease

BACKGROUND

CKD leads to vitamin D deficiency. Treatment with vitamin D receptor agonists (VDRAs) may have nephroprotective and anti-inflammatory actions, but their mechanisms of action are poorly understood.

METHODS

Modulation of the noncanonical NF-κB2 pathway and its component TNF receptor-associated factor 3 (TRAF3) by the VDRA paricalcitol was studied in PBMCs from patients with ESKD, cytokine-stimulated cells, and preclinical kidney injury models.

RESULTS

In PBMCs isolated from patients with ESKD, TRAF3 protein levels were lower than in healthy controls. This finding was associated with evidence of noncanonical NF-κB2 activation and a proinflammatory state. However, PBMCs from patients with ESKD treated with paricalcitol did not exhibit these features. Experiments in cultured cells confirmed the link between TRAF3 and NF-κB2/inflammation. Decreased TRAF3 ubiquitination in K48-linked chains and cIAP1-TRAF3 interaction mediated the mechanisms of paricalcitol action.TRAF3 overexpression by CRISPR/Cas9 technology mimicked VDRA's effects. In a preclinical model of kidney injury, paricalcitol inhibited renal NF-κB2 activation and decreased renal inflammation. In VDR knockout mice with renal injury, paricalcitol prevented TRAF3 downregulation and NF-κB2-dependent gene upregulation, suggesting a VDR-independent anti-inflammatory effect of paricalcitol.

CONCLUSIONS

These data suggest the anti-inflammatory actions of paricalcitol depend on TRAF3 modulation and subsequent inhibition of the noncanonical NF-κB2 pathway, identifying a novel mechanism for VDRA's effects. Circulating TRAF3 levels could be a biomarker of renal damage associated with the inflammatory state.

Monocyte to high-density lipoprotein ratio and cardiovascular events in patients on peritoneal dialysis

BACKGROUND AND AIMS

The monocyte to high-density lipoprotein cholesterol ratio (MHR) is associated with multiple cardiovascular diseases. However, the role of the MHR in predicting cardiovascular diseases in patients on peritoneal dialysis remains unclear.

METHODS AND RESULTS

Eight hundred and eighty incident peritoneal dialysis patients were enrolled from November 1, 2005, to February 28, 2017, and followed until May 31, 2017. Primary outcomes were cardiovascular events. Using the X-tile program, these patients were divided into three groups according to the MHR. Kaplan-Meier method and Cox regressions were used for survival analysis. During a median follow-up period of 26 months (interquartile range: 12-39 months), 139 cardiovascular events were recorded. After multiple adjustment, the high MHR group was associated with a 1.97-fold increase in the cardiovascular events hazard compared to that of the low group in the overall population (hazard ratio: 1.97; 95% CI, 1.19-3.28; P = 0.009). Subgroup analysis demonstrated that the association between the MHR and a higher risk of cardiovascular events was strongest in the subgroup of patients with diabetes (P for interaction = 0.004). In this subgroup, the high MHR group was found to be associated with a higher risk of cardiovascular events compared to the low group (hazard ratio: 7.69; 95% CI, 2.76-21.47).

CONCLUSION

This study suggests that the MHR is independently associated with the risk of cardiovascular events in patients undergoing peritoneal dialysis, and diabetes status can influence the association between the MHR and the risk of cardiovascular events.

How do Uremic Toxins Affect the Endothelium?

Uremic toxins can induce endothelial dysfunction in patients with chronic kidney disease (CKD). Indeed, the structure of the endothelial monolayer is damaged in CKD, and studies have shown that the uremic toxins contribute to the loss of cell–cell junctions, increasing permeability. Membrane proteins, such as transporters and receptors, can mediate the interaction between uremic toxins and endothelial cells. In these cells, uremic toxins induce oxidative stress and activation of signaling pathways, including the aryl hydrocarbon receptor (AhR), nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways. The activation of these pathways leads to overexpression of proinflammatory (e.g., monocyte chemoattractant protein-1, E-selectin) and prothrombotic (e.g., tissue factor) proteins. Uremic toxins also induce the formation of endothelial microparticles (EMPs), which can lead to the activation and dysfunction of other cells, and modulate the expression of microRNAs that have an important role in the regulation of cellular processes. The resulting endothelial dysfunction contributes to the pathogenesis of cardiovascular diseases, such as atherosclerosis and thrombotic events. Therefore, uremic toxins as well as the pathways they modulated may be potential targets for therapies in order to improve treatment for patients with CKD.

Atherosclerosis in Chronic Kidney Disease: More, Less, or Just Different?

Patients with chronic kidney disease (CKD) are at an increased risk of premature mortality, mainly from cardiovascular causes. The association between CKD on hemodialysis and accelerated atherosclerosis was described >40 years ago. However, more recently, it has been suggested that the increase in atherosclerosis risk is actually observed in early CKD stages, remaining stable thereafter. In this regard, interventions targeting the pathogenesis of atherosclerosis, such as statins, successful in the general population, have failed to benefit patients with very advanced CKD. This raises the issue of the relative contribution of atherosclerosis versus other forms of cardiovascular injury such as arteriosclerosis or myocardial injury to the increased cardiovascular risk in CKD. In this review, the pathophysiogical contributors to atherosclerosis in CKD that are shared with the general population, or specific to CKD, are discussed. The NEFRONA study (Observatorio Nacional de Atherosclerosis en NEFrologia) prospectively assessed the prevalence and progression of subclinical atherosclerosis (plaque in vascular ultrasound), confirming an increased prevalence of atherosclerosis in patients with moderate CKD. However, the adjusted odds ratio for subclinical atherosclerosis increased with CKD stage, suggesting a contribution of CKD itself to subclinical atherosclerosis. Progression of atherosclerosis was closely related to CKD progression as well as to the baseline presence of atheroma plaque, and to higher phosphate, uric acid, and ferritin and lower 25(OH) vitamin D levels. These insights may help design future clinical trials of stratified personalized medicine targeting atherosclerosis in patients with CKD. Future primary prevention trials should enroll patients with evidence of subclinical atherosclerosis and should provide a comprehensive control of all known risk factors in addition to testing any additional intervention or placebo.

Machine learning analysis of serum biomarkers for cardiovascular risk assessment in chronic kidney disease

Background

Chronic kidney disease (CKD) patients show an increased burden of atherosclerosis and high risk of cardiovascular events (CVEs). There are several biomarkers described as being associated with CVEs, but their combined effectiveness in cardiovascular risk stratification in CKD has not been tested. The objective of this work is to analyse the combined ability of 19 biomarkers associated with atheromatous disease in predicting CVEs after 4 years of follow-up in a subcohort of the NEFRONA study in individuals with different stages of CKD without previous CVEs.

Methods

Nineteen putative biomarkers were quantified in 1366 patients (73 CVEs) and their ability to predict CVEs was ranked by random survival forest (RSF) analysis. The factors associated with CVEs were tested in Fine and Gray (FG) regression models, with non-cardiovascular death and kidney transplant as competing events.

Results

RSF analysis detected several biomarkers as relevant for predicting CVEs. Inclusion of those biomarkers in an FG model showed that high levels of osteopontin, osteoprotegerin, matrix metalloproteinase-9 and vascular endothelial growth factor increased the risk for CVEs, but only marginally improved the discrimination obtained with classical clinical parameters: concordance index 0.744 (95% confidence interval 0.609–0.878) versus 0.723 (0.592–0.854), respectively. However, in individuals with diabetes treated with antihypertensives and lipid-lowering drugs, the determination of these biomarkers could help to improve cardiovascular risk estimates.

Conclusions

We conclude that the determination of four biomarkers in the serum of CKD patients could improve cardiovascular risk prediction in high-risk individuals.

Subclinical atherosclerosis burden predicts cardiovascular events in individuals with diabetes and chronic kidney disease

Background

Individuals with diabetes have remarkably high rates of cardiovascular morbidity and mortality. However, the incremental cardiovascular risk in diabetes is heterogeneous and has often been related to renal involvement. The purpose of this study was to analyse the prognostic value of subclinical atherosclerosis in determining the incidence of first cardiovascular events (CVEs) in individuals with diabetes and chronic kidney disease (CKD) compared to CKD individuals without diabetes.

Methods

We included data from individuals with CKD with and without diabetes, free from pre-existing cardiovascular disease, from the NEFRONA cohort. Participants underwent baseline carotid and femoral ultrasound and were followed up for 4 years. All CVEs during follow-up were registered. Bivariate analysis and Fine–Gray competing risk models were used to perform the statistical analysis.

Results

During the mean follow-up time of 48 months, a total of 203 CVE was registered. 107 CVE occurred among participants without diabetes (19.58 per 1000 person-years) and 96 CVE occurred among participants with diabetes (44.44 per 1000 person-years). Following the competing risk analysis, the variables predicting CVEs in CKD individuals without diabetes were the number of territories with plaque at baseline (HR 1.862, 95% CI [1.432;2.240]), age (HR 1.026, 95% CI [1.003;1.049]) and serum concentrations of 25-OH vitamin D (HR 0.963, 95% CI [0.933;0.094]). The only variable predicting CVEs among CKD participants with diabetes was the number of territories with plaque at baseline (HR 1.782, 95% CI [1.393, 2.278]). For both models, concordance (C) index yielded was over 0.7.

Conclusions

The burden of subclinical atherosclerosis is the strongest predictor of future CVEs in diabetic individuals with CKD. Early detection of subclinical atherosclerotic burden by multiterritorial vascular ultrasound could improve CVE prediction in this population.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0897-y) contains supplementary material, which is available to authorized users.

An in-depth analysis shows a hidden atherogenic lipoprotein profile in non-diabetic chronic kidney disease patients

Background: Chronic kidney disease (CKD) is an independent risk factor for atherosclerotic disease. We hypothesized that CKD promotes a proatherogenic lipid profile modifying lipoprotein composition and particle number. Methods: Cross-sectional study in 395 non-diabetic individuals (209 CKD patients and 186 controls) without statin therapy. Conventional lipid determinations were combined with advanced lipoprotein profiling by nuclear magnetic resonance, and their discrimination ability was assessed by machine learning. Results: CKD patients showed an increase of very-low-density (VLDL) particles and a reduction of LDL particle size. Cholesterol and triglyceride content of VLDLs and intermediate-density (IDL) particles increased. However, low-density (LDL) and high-density (HDL) lipoproteins gained triglycerides and lost cholesterol. Total-Cholesterol, HDL-Cholesterol, LDL-Cholesterol, non-HDL-Cholesterol and Proprotein convertase subtilisin-kexin type (PCSK9) were negatively associated with CKD stages, whereas triglycerides, lipoprotein(a), remnant cholesterol, and the PCSK9/LDL-Cholesterol ratio were positively associated. PCSK9 was positively associated with total-Cholesterol, LDL-Cholesterol, LDL-triglycerides, LDL particle number, IDL-Cholesterol, and remnant cholesterol. Machine learning analysis by random forest revealed that new parameters have a higher discrimination ability to classify patients into the CKD group, compared to traditional parameters alone: area under the ROC curve (95% CI), .789 (.711, .853) vs .687 (.611, .755). Conclusions: non-diabetic CKD patients have a hidden proatherogenic lipoprotein profile.

The rs1126616 Single Nucleotide Polymorphism of the Osteopontin Gene Is Independently Associated with Cardiovascular Events in a Chronic Kidney Disease Cohort

Chronic kidney disease (CKD) is associated with a higher risk of cardiovascular events (CVE), partly due to the higher burden of atherosclerosis. Circulating Osteopontin (OPN) levels have been also shown to have a potential role in the development of atherosclerosis. Indeed, CKD patients show an increase in circulating OPN levels, but their effect of CKD-related atherosclerosis is not clear. Polymorphisms in the OPN gene (SPP1) have been studied in atheromatous disease, but reported results show conflictive findings. Thus, the main aim of the present study is to analyze the influence of SPP1 polymorphisms in CVE in CKD patients, taking into account circulating OPN levels. We followed 559 healthy controls and 2445 CKD patients without previous CVE from the National Observatory of Atherosclerosis in Nephrology study (NEFRONA study). After 48 months of follow-up 206 CVE were recorded. Genotyping for rs9138, rs1126616, rs1126772, rs11730582 and rs28357094 polymorphisms of the SPP1 gene was performed along with the measurements of plasma OPN levels. The group of patients with CVE showed higher incidence of atherosclerotic plaque (90.3% vs 64.5%; p < 0.001) and higher OPN levels (p < 0.001) at baseline. Patients with the heterozygous genotype of the rs1126616 polymorphism showed a higher hazard ratio of having a CVE, even after adjustment for multiple potential confounders. After adjustment, OPN levels were no longer associated with the incidence of CVE. We found that the rs1126616 single nucleotide polymorphism (SNP) of the SPP1 gene is independently associated with a higher incidence of CVE in a cohort of CKD patients and that it could be used to predict CVE risk.

Peritoneal Dialysis Is an Independent Factor Associated to Lower Intima Media Thickness in Dialysis Patients Free From Previous Cardiovascular Disease

Carotid intima media thickness (cIMT) displays prognostic value as a marker of cardiovascular risk in dialysis patients. However, few data are available regarding the impact of dialysis modality on cIMT. The aim of this study is to determine whether the modality of dialysis influences cIMT values. We compared 237 peritoneal dialysis (PD) and 451 hemodialysis (HD) patients without previous cardiovascular disease included in NEFRONA, a prospective, observational and multicenter study. This cross sectional study included the determination of cIMT in 6 carotid territories by arterial ultrasound. cIMT was determined in territories without atheroma plaque and averaged. A second analysis was performed using all territories, giving a truncated cIMT value of 1,5 mm to territories presenting with atheroma plaque. Age and plaque presence at baseline were the clinical variables more closely associated to cIMT in dialysis patients. The evaluation of the impact of the modality of dialysis on cIMT showed that PD patients had lower cIMT than HD patients, both in territories with no plaques and when using truncated cIMT values. No differences were found between right and left sides, neither in cIMT or truncated cIMT values. Lineal multivariate analysis adjusted by several clinical variables showed a statistically significant association of PD with a lower cIMT (slope -0.036; SD 0.010). These results were also confirmed when truncated cIMT values were used. We conclude that the modality of dialysis has an impact on cITM. HD patients have greater global cIMT than PD patients, and PD is and independent factor associated with a lower cIMT.

Contribution of uraemic toxins to the vascular fibrosis associated with chronic kidney disease

BACKGROUND

Patients with chronic kidney disease present with an accumulation of uraemic toxins, which have been identified as pathogenic agents associated with cardiovascular mortality, which is very high is this patient group. A phenomenon common to the progressive renal dysfunction and associated vascular damage, is the abnormal accumulation of extracellular matrix (ECM) proteins in the renal or vascular structures.

OBJECTIVE

To determine the contribution of uraemia or the uraemic toxins to the production of cytokinins and ECM in aortas of uraemic animals or human aortic smooth muscle cells (HASMCs).

MATERIALS AND METHODS

Mice were used with uraemia induced by a diet rich in adenine (0.2%) for 2, 4 or 6 weeks. Kidney function was evaluated by means of urine volume, plasma levels of creatinine, urea, fractional excretion of sodium, and vascular damage using histology, as well as protein expression using RT-qPCR. The HASMCs were incubated in vitro with uraemic toxins: p-cresol 10-100 (μg/ml) and indoxyl-sulphate25-100 (μg/ml) alone or simultaneously. The protein expression was evaluated using Western blot and confocal microscopy.

RESULTS

The administration of adenine produced progressive kidney damage in the mice, thickening of the aortic wall, and increasing the expression of TGF-β1 and ECM proteins. The toxins at high doses and combined also induced the expression of TGF-β1 and ECM proteins by the HASMCs.

CONCLUSIONS

The uraemia produced by an adenine rich diet or high doses of uraemic toxins induced the abnormal deposit of ECM proteins in the vascular wall or its production by HASMCs. The understanding of the mechanisms that underlie this pathophysiological process may be useful in the prevention of cardiovascular damage associated with the progress of chronic kidney disease, a disease, at the moment that is irreversible and occasional silent until its diagnosis in advanced stages.

Relationship between low levels of circulating TRAIL and atheromatosis progression in patients with chronic kidney disease

Background

Chronic kidney disease (CKD) patients experience a high risk of cardiovascular disease (CV); however, the factors involved in CV-related morbidity and mortality in these patients have not been fully defined. Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) is a cytokine, which exhibits pleiotropic activities on endothelial, vascular smooth muscle and inflammatory cells, with relevant effects on atheromatous plaque formation. On this basis, the present study aims to investigate the role of TRAIL in atheromatosis progression in CKD patients.

Methods

Circulating TRAIL levels were measured in 378 CKD patients belonging to the Spanish National Observatory of Atherosclerosis in Nephrology (NEFRONA) study. All patients were free of previous CV events. Carotid and femoral B-mode ultrasound was performed to detect the presence of plaque at baseline and after 24 months of follow-up.

Results

The lowest levels of TRAIL at baseline were significantly (p<0.05) associated with the appearance, after 24 months of follow-up, of at least two new atheromatous plaques in all territories and of one new plaque in the carotid artery, even after adjusting for CV risk factors. In addition, the patients with low levels of TRAIL at baseline were characterized by the presence of at least one hypoechoic plaque in the carotid artery. This association was significant (p<0.05) even after adjusting for CKD stage.

Conclusions

Overall, the results of our study suggest TRAIL as an assertable independent prognostic biomarker for atheromatosis plaque formation in CKD patients. This observation further supports the potential role of TRAIL for the prevention/treatment of CV disease.

Prevalence and progression of subclinical atherosclerosis in patients with chronic kidney disease and diabetes

BACKGROUND AND AIMS

Cardiovascular disease is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD) and diabetes. Traditional cardiovascular risk factors fail to fully account for the increase in cardiovascular risk in these patients. This study aims to analyse the prevalence and progression of subclinical atherosclerosis in CKD patients with and without diabetes.

METHODS

We included data from CKD patients with and without diabetes free from previous cardiovascular events from the NEFRONA cohort. Patients underwent baseline and 24-month follow-up carotid and femoral ultrasound examinations. Multivariable models were used to assess the contribution of diabetes to the presence and plaque progression.

RESULTS

A total of 419 patients with diabetes and 1129 without diabetes were included. Diabetic patients were older, had higher BMIs, more hypertension and dyslipidaemia. At baseline, the proportion of patients with plaque was higher among diabetic patients (81.4% vs. 64.1%, p < 0.001). Diabetic patients more frequently had more than two vascular territories with plaque (64.4% vs. 48.4%, p < 0.001). Multivariable analysis indicated that plaque at baseline was significantly associated with age, gender, smoking and renal replacement therapy (RRT) in the non-diabetic patients, but only with age and male gender in diabetic patients. Plaque progression was significantly associated with age, number of territories with basal plaque, smoking and RRT in both groups.

CONCLUSIONS

Subclinical atherosclerosis is more prevalent, carries a higher plaque burden and is more rapidly progressive in renal patients with diabetes. In these patients, diabetes outweighs other described risk factors associated with the presence of subclinical atherosclerosis.

Association of the rs495392 Klotho polymorphism with atheromatosis progression in patients with chronic kidney disease

Background

Prevalence of atherosclerotic cardiovascular disease and its rate of progression are higher in patients with chronic kidney disease (CKD) compared with the general population. Mineral metabolism parameters have been shown to be involved in the increased velocity of atheromatosis progression. The aim of this study is to determine the role of 11 single-nucleotide polymorphisms (SNPs) of the Klotho gene on the rate of atherosclerosis progression in CKD.

Methods

This was a multicentre, prospective, observational study of 1439 CKD patients from the NEFRONA cohort. Carotid and femoral ultrasounds were performed at baseline and after 24 months in 10 arterial territories. Progression of atheromatosis was defined as an increase in the number of territories with plaque. Genotyping of 11 SNPs of the Klotho gene was performed and its association with atheromatosis progression was determined by multivariate logistic regression.

Results

Bivariate analysis showed that none of the 11 SNPs was associated with atheroma plaque prevalence, but 3 of them (rs495392, rs562020 and rs567170) showed association with atheromatosis progression. The multivariate analysis revealed that only rs495392 showed a statistically significant association with atheromatosis progression, after adjustment for several parameters known to affect it in CKD patients. Thus, the presence of one allele T was associated with a reduction of 30% of the odds of progression, whereas the presence of the two T alleles was associated with a decrease close to 50%.

Conclusions

The presence of the allele T of the SNP rs495392 of the Klotho gene is associated with a decrease in the odds of progression of atheromatosis in CKD patients.

Association of Monocyte Chemoattractant Protein-1 with Death and Atherosclerotic Events in Chronic Kidney Disease

BACKGROUND

Monocyte chemoattractant protein-1 -(MCP-1), a marker of inflammation and monocyte recruitment to atherosclerotic plaques, is associated with cardiovascular (CV) outcomes in patients with acute coronary syndrome. Although plasma levels are elevated in chronic kidney disease (CKD), associations with reduced kidney function or outcomes in CKD have not been explored.

METHODS

In this population-based, probability-sampled, longitudinal cohort of 3,257 participants, including 286 (8.8%) patients with CKD, we studied the association of plasma MCP-1 with estimated glomerular filtration rate (eGFR), albuminuria, death, and intermediate and hard CV outcomes in CKD and non-CKD individuals. Cox proportional hazards regression assessed associations of baseline MCP-1 with all-cause death and atherosclerotic events.

RESULTS

MCP-1 was higher in CKD than non-CKD participants (p < 0.001), and negatively associated with eGFR (r = -0.23, p < 0.0001) but not albuminuria in CKD. MCP-1 was associated with pulse wave velocity and coronary artery calcification in non-CKD but not CKD individuals. At 13.5 years, there were 230 (7.7%) deaths and 168 (6.4%) atherosclerotic events in the non-CKD vs. 97 (34.0%) deaths and 62 (27.9%) events in the CKD group (p < 0.001 for each). MCP-1 was associated with death (hazards ratio [HR] 2.0 [1.4-2.9] per log-unit increase) and atherosclerotic events (1.7 [1.0-2.9]) in CKD individuals. The HR for death in CKD remained significant (1.6 [1.1-2.3]) after adjusting for CV risk factors.

CONCLUSIONS

Although plasma MCP-1 increased with decreased eGFR, it remained an independent risk factor for death in CKD. MCP-1 did not correlate with intermediate CV outcomes, implicating pathways other than atherosclerosis in the association of MCP-1 with death in CKD.

[Cardiovascular consequences of chronic kidney disease, impact of modulation of epoxyeicosatrienoic acids]

Cardiovascular events are more prevalent in chronic kidney disease than in the general population, being the main cause of morbi-mortality. The physiopathology explaining this association remains complex. Thus, research for new therapies to prevent cardiovascular events in chronic kidney disease is a major issue. Epoxyeicosatrienoic acids, products of the arachidonic acid metabolism, are endothelium-derived hyperpolarizing factors with vasodilatory, anti-inflammatory, thrombolytic, pro-angiogenic and anti-apoptotic properties. A decrease in the bioavailability of epoxyeicosatrienoic acids has been observed in many cardiovascular diseases such as hypertension, myocardial infarction or diabetes. Moreover, human studies of genetic polymorphisms of soluble epoxide hydrolase, the enzyme degrading epoxyeicoatrienoic acids, have shown that allelic variants related to an increase in its activity is associated with higher risk of cardiovascular events. Modulation of epoxyeicosatrienoic acids by soluble epoxide hydrolase inhibitors in some cardiovascular diseases induces structural improvements in the heart, vessels and kidneys, including decrease in cardiomyocyte hypertrophy, reduction in cardiac and renal interstitial fibrosis, improvement in renal hemodynamics, and prevention of endothelial dysfunction. In this context, increasing the bioavailability of epoxyeicosatrienoic acids appears to be an interesting therapeutic option in the prevention of cardiovascular events related to chronic kidney disease.

Association of FGF-2 Concentrations with Atheroma Progression in Chronic Kidney Disease Patients

BACKGROUND AND OBJECTIVES

Atherosclerosis is highly prevalent in CKD. The rate of progression of atherosclerosis is associated with cardiovascular events. Fibroblast growth factor 2 (FGF-2) is a member of the FGF family with potentially both protective and deleterious effects in the development of atherosclerosis. The role of circulating FGF-2 levels in the progression of atherosclerosis in CKD is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used a multicenter, prospective, observational cohorts study of 481 patients with CKD. We determined the presence of atheroma plaque in ten arterial territories by carotid and femoral ultrasounds. Progression of atheromatosis was defined as an increase in the number of territories with plaque after 24 months. Plasma levels of FGF-2 were measured by multiplex analysis. A multivariable logistic regression analysis was performed to determine whether plasma FGF-2 levels were associated with atheromatosis progression.

RESULTS

Average age of the population was 61 years. The percentage of patients in each CKD stage was 51% in stage 3, 41% in stages 4-5, and 8% in dialysis. A total of 335 patients (70%) showed plaque at baseline. Atheromatosis progressed in 289 patients (67%). FGF-2 levels were similar between patients with or without plaque at baseline (79 versus 88 pg/ml), but lower in patients with atheromatosis progression after 2 years (78 versus 98 pg/ml; P<0.01). In adjusted analyses, higher plasma FGF-2 was associated with lower risk of atheromatosis progression (odds ratio [OR], 0.86; 95% confidence interval [95% CI], 0.76 to 0.96; per 50 pg/ml increment). Analysis of FGF-2 in tertiles showed that atheroma progression was observed for 102 participants in the lowest tertile of FGF-2 (reference group), 86 participants in the middle tertile of FGF-2 (adjusted OR, 0.70; 95% CI, 0.40 to 1.20), and 74 participants in the lowest tertile of FGF-2 (adjusted OR, 0.48; 95% CI, 0.28 to 0.82).

CONCLUSIONS

Low FGF-2 levels are independently associated with atheromatosis progression in CKD.

Any grade of relative overhydration is associated with long-term mortality in patients with Stages 4 and 5 non-dialysis chronic kidney disease

Background

Overhydration (OH) is associated with mortality in chronic kidney disease (CKD). A relative overhydration adjusted for extracellular water (OH/ECW) measured by bioimpedance >15% has shown an increased mortality risk in haemodialysis but few studies have been developed in advanced CKD. Our objective was to evaluate the effect of OH on mortality in patients with Stage 4 or 5 non-dialysis CKD.

Methods

We performed a prospective study of 356 patients enrolled in 2011 and followed up until 2016. At baseline we collected general characteristics, serum inflammatory and nutrition markers, cardiovascular events (CVEs) and body composition using bioimpedance spectroscopy. During a median follow-up of 50 (24–66) months we collected mortality data.

Results

The mean creatinine was 3.5 ± 1.3 mg/dL, median proteinuria was 0.5 [interquartile range (IQR) 0.2–1.5] g/24 h, median OH was 0.6 (IQR −0.4–1.5) L and mean relative OH (OH/ECW) was 2.3 ± 0.8%. We found that 32% of patients died. The univariate Cox analysis showed an association between mortality and age, diabetes, previous CVEs, Charlson comorbidity index, low albumin and pre-albumin, high C-reactive protein (CRP), low lean tissue and high OH/ECW. Multivariate Cox analysis confirmed an association between mortality and age {exp(B) 1.1 [95% confidence interval (CI) 1.0–1.3]; P = 0.001}, Charlson comorbidity index [exp(B) 1.1 (95% CI 1.0–1.2); P = 0.01], CRP [exp(B) 1.1 (95% CI 1.0–1.2); P = 0.04], OH/ECW [exp(B) 3.18 (95% CI 2.09–4.97); P = 0.031] and low lean tissue [exp(B) 0.82 (95% CI 0.69–0.98); P = 0.002]. Kaplan–Meier analysis confirmed higher mortality in patients with OH/ECW >0% (log rank 11.1; P = 0.001).

Conclusion

Any grade of relative OH measured by OH/ECW >0% is associated with long-term mortality in patients with Stage 4 or 5 non-dialysis CKD.

Deleterious effects of phosphate on vascular and endothelial function via disruption to the nitric oxide pathway

Background

Hyperphosphataemia is an independent risk factor for accelerated cardiovascular disease in chronic kidney disease (CKD), although the mechanism for this is poorly understood. We investigated the effects of sustained exposure to a high-phosphate environment on endothelial function in cellular and preclinical models, as well as in human subjects.

Methods

Resistance vessels from rats and humans (± CKD) were incubated in a normal (1.18 mM) or high (2.5 mM) phosphate concentration solution and cells were cultured in normal- (0.5 mM) or high-phosphate (3 mM) concentration media. A single-blind crossover study was performed in healthy volunteers, receiving phosphate supplements or a phosphate binder (lanthanum), and endothelial function measured was by flow-mediated dilatation.

Results

Endothelium-dependent vasodilatation was impaired when resistance vessels were exposed to high phosphate; this could be reversed in the presence of a phosphodiesterase-5-inhibitor. Vessels from patients with CKD relaxed normally when incubated in normal-phosphate conditions, suggesting that the detrimental effects of phosphate may be reversible. Exposure to high-phosphate disrupted the whole nitric oxide pathway with reduced nitric oxide and cyclic guanosine monophosphate production and total and phospho endothelial nitric oxide synthase expression. In humans, endothelial function was reduced by chronic phosphate loading independent of serum phosphate, but was associated with higher urinary phosphate excretion and serum fibroblast growth factor 23.

Conclusions

These directly detrimental effects of phosphate, independent of other factors in the uraemic environment, may explain the increased cardiovascular risk associated with phosphate in CKD.

Mineral metabolism factors predict accelerated progression of common carotid intima-media thickness in chronic kidney disease: the NEFRONA study

Background

The leading cause of premature death in chronic kidney disease (CKD) is cardiovascular disease (CVD), but risk assessment in renal patients is challenging. The aim of the study was to analyse the factors that predict accelerated progression of common carotid intima-media thickness (CCIMT) in a CKD cohort after 2 years of follow-up (2010-12).

Methods

The study included 1152 patients from the NEFRONA cohort with CKD stages 3-5D and without a clinical history of CVD. CCIMT was measured at the far wall on both common carotids. CCIMT progression was defined as the change between CCIMT at baseline and at 24 months for each side, averaged and normalized as change per year. Accelerated progressors were defined as those with a CCIMT change ≥75th percentile.

Results

The median CCIMT progression rate was 0.0125 mm/year, without significant differences between CKD stages. The cut-off value for defining accelerated progression was 0.0425 mm/year. After adjustment, age was a common factor among all CKD stages. Traditional cardiovascular risk factors, such as diabetes and systolic blood pressure, were predictors of progression in CKD stages 4-5, whereas high-density lipoprotein and low-density lipoprotein cholesterol predicted progression in women in stage 3. Mineral metabolism factors predicting accelerated progression were serum phosphorus in stages 3 and 5D; low 25-hydroxyvitamin D and parathyroid hormone levels >110 pg/mL in stages 4-5 and intact parathyroid hormone levels out of the recommended range in stage 5D.

Conclusions

Mineral metabolism parameters might predict accelerated CCIMT progression from early CKD stages.

Factors influencing pathological ankle-brachial index values along the chronic kidney disease spectrum: the NEFRONA study

Background

The ankle-brachial index (ABI) is widely used to diagnose subclinical peripheral artery disease (PAD) in the general population, but data assessing its prevalence and related factors in different chronic kidney disease (CKD) stages are scarce. The aim of this study is to evaluate the prevalence and associated factors of pathological ABI values in CKD patients.

Methods

NEFRONA is a multicentre prospective project that included 2445 CKD patients from 81 centres and 559 non-CKD subjects from 9 primary care centres across Spain. A trained team collected clinical and laboratory data, performed vascular ultrasounds and measured the ABI.

Results

PAD prevalence was higher in CKD than in controls (28.0 versus 12.3%, P < 0.001). Prevalence increased in more advanced CKD stages, due to more patients with an ABI ≥1.4, rather than ≤0.9. Diabetes was the only factor predicting both pathological values in all CKD stages. Age, female sex, carotid plaques, higher carotid intima-media thickness, higher high-sensitivity C-reactive protein (hsCRP) and triglycerides, and lower 25-hydroxi-vitamin D were independently associated with an ABI ≤0.9. Higher phosphate and hsCRP, lower low-density lipoprotein (LDL)-cholesterol and dialysis were associated with an ABI ≥1.4. A stratified analysis showed different associated factors in each CKD stage, with phosphate being especially important in earlier CKD, and LDL-cholesterol being an independent predictor only in Sage 5D CKD.

Conclusions

Asymptomatic PAD is very prevalent in all CKD stages, but factors related to a low or high pathological ABI differ, revealing different pathogenic pathways. Diabetes, dyslipidaemia, inflammation and mineral-bone disorders play a role in the appearance of PAD in CKD.

Factors predicting cardiovascular events in chronic kidney disease patients. Role of subclinical atheromatosis extent assessed by vascular ultrasound

Patients with chronic kidney disease (CKD) have an increased incidence of cardiovascular events (CVE). The contribution of subclinical atheromatosis extent, including femoral arteries, to CVE in CKD patients has not been investigated. In this paper, we examine the prognostic value of subclinical atheromatosis extent, assessed as the number of arterial territories with plaque, in predicting the incidence of major and minor CVE. The NEFRONA is a multicenter, prospective cohorts study that recruited 2445 CKD subjects and 559 controls, free from previous cardiovascular disease, in 81 medical centers across Spain. The presence of atheroma plaque was assessed by arterial ultrasound in ten arterial territories (carotid and femoral). The predictive power of the presence or absence of atheroma plaque in any territory was compared with the quantification of atheroma extent as the number of territories with plaque. During the median follow up of 48 months, 216 CVE were reported. Factors predicting the incidence of CVE in the whole cohort were being male, CKD patient, lower levels of 25(OH) vitamin D, higher levels of cholesterol and the extent of subclinical atheromatosis, yielding a higher concordance (C) index than the presence or absence of plaque. In stratified analysis including specific factors of CKD patients not on dialysis, the variables predicting CVE were the same as in the whole cohort, plus higher levels of potassium. Again, the inclusion of the information about atheromatosis as number of territories with plaque, presented a higher C index than the presence or absence of plaque. In the dialysis population, significant variables were older age, diabetes, dialysis vintage and higher levels of cholesterol and phosphate. In this case the higher C index was obtained with the information about plaque presence.

Subclinical atheromatosis extent, including femoral arteries, influences CVE in CKD and its detection could improve the prediction of cardiovascular events.

New perspectives on CKD-induced dyslipidemia

INTRODUCTION

Chronic kidney disease (CKD) is a world-wide health concern associated with a significantly higher cardiovascular morbidity and mortality. One of the principal cardiovascular risk factors is the lipid profile. CKD patients have a more frequent and progressive atheromatous disease that cannot be explained by the classical lipid parameters used in the daily clinical practice. Areas covered: The current review summarizes prevailing knowledge on the role of lipids in atheromathosis in CKD patients, including an overview of lipoprotein metabolism highlighting the CKD-induced alterations. Moreover, to obtain information beyond traditional lipid parameters, new state-of-the-art technologies such as lipoprotein subfraction profiling and lipidomics are also reviewed. Finally, we analyse the potential of new lipoprotein subclasses as therapeutic targets in CKD. Expert opinion: The CKD-induced lipid profile has specific features distinct from the general population. Besides quantitative alterations, renal patients have a plethora of qualitative lipid alterations that cannot be detected by routine determinations and are responsible for the excess of cardiovascular risk. New parameters, such as lipoprotein particle number and size, together with new biomarkers obtained by lipidomics will personalize the management of these patients. Therefore, nephrologists need to be aware of new insights into lipoprotein metabolism to improve cardiovascular risk assessment.

Preclinical carotid atherosclerosis in patients with latent autoimmune diabetes in adults (LADA), type 2 diabetes and classical type 1 diabetes

BACKGROUND

LADA is probably the most prevalent form of autoimmune diabetes. Nevertheless, there are few data about cardiovascular disease in this group of patients. The aim of this study was to investigate the frequency of carotid atherosclerotic plaques in patients with LADA as compared with patients with classic type 1 diabetes and type 2 diabetes.

METHODS

Patients with LADA were matched for age and gender in different proportions to patients with type 2 diabetes, and classic type 1 diabetes. None of the patients had clinical cardiovascular disease. All subjects underwent B-mode carotid ultrasound to detect atheroma plaques. Demographics were obtained from all subjects.

RESULTS

We included 71 patients with LADA, 191 patients with type 2 diabetes and 116 patients with type 1 diabetes. Carotid atherosclerosis was more frequent in patients with LADA compared with type 2 diabetes (73.2% vs. 56.9%, P = 0.0018) and classic type 1 diabetes (57.1%, P = 0.026); these changes occurred despite healthier macrovascular risk profiles in the former. Age (P < 0.001), smoking (P = 0.003) and hypertension (P = 0.019) were independently associated with carotid atherosclerosis. Multiple plaques were also more frequent in patients with LADA as compared with classic type 1 diabetes and type 2 diabetes (45.1% and 33.6% vs. 27.2%, respectively, P = 0.022). The frequency of carotid plaques increased with increasing diabetes duration in LADA patients compared with type 2 diabetes (85.7% vs. 58.8%, inverse OR 5.72 [1.5-21.8]; P = 0.009).

CONCLUSIONS

LADA patients do not present with less carotid atherosclerosis than patients with type 1 and type 2 diabetes. Their macrovascular risk occurs despite a healthier macrovascular risk profile than those patients with type 2 diabetes.

Pulse Pressure, Instead of Brachium-Ankle Pulse Wave Velocity, is Associated with Reduced Kidney Function in a Chinese Han Population

BACKGROUND/AIMS

In this study, we aim to investigate the association between renal function and arterial stiffness in a Chinese Han population, and further to discuss the effects of smoking on renal function.

METHODS

We collected the data of the brachium-ankle pulse wave velocity (baPWV), blood pressure, blood chemistry and smoking status. Then, the multiple linear regression was done to explore the relationship between estimated glomerular filtration (eGFR) and baPWV. Further, the parameters were compared among the four groups divided according to the quartiles of baPWV. Finally, the baPWV, eGFR and albuminuria values were compared between smokers and non-smokers.

RESULTS

baPWV is associated with eGFR in the correlation analysis and univariate linear regression model. After adjustment, the pulse pressure (PP) instead of baPWV showed a significant association with eGFR. Nevertheless, the eGFR values differed among the four baPWV groups; the baPWV values were significantly higher in the subjects at the CKD (eGFR<60 mL/min/1.73 m2) and the early CKD stage (eGFR60-80 mL/min/1.73 m2). The baPWV values and the ratio of proteinuria were significantly increased in smokers.

CONCLUSION

PP but not baPWV is a predictor of declined renal function. Smokers have worse arterial stiffness and worse renal function.