Cardiovascular risk factors underestimate atherosclerotic burden in chronic kidney disease: usefulness of non-invasive tests in cardiovascular assessment

Phosphate and Coronary Artery Disease in Patients with Chronic Kidney Disease

Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD). Both traditional and CKD-related factors are associated with CVD in CKD patients. Traditional factors that play an important role in the atherosclerotic process directly contribute to a higher risk of coronary artery disease in patients with early-stage CKD. Among CKD-related factors, CKD-mineral and bone disorder plays a critical role in the pathomechanism of nonatherosclerotic diseases, which increases the risk of cardiovascular morbidity and mortality in patients with advanced CKD. Higher serum phosphate levels were significantly associated with cardiovascular events and all-cause mortality in patients with or without CKD. An increased phosphate load, directly and indirectly, promotes arterial medial calcification and left ventricular hypertrophy, both of which predispose patients to coronary artery disease. Calciprotein particles that form in a hyperphosphatemic state promote the transformation of vascular smooth muscle cells (VSMCs) into osteoblastic cells, thereby providing a scaffold for medial calcification in the artery. Increases in fibroblast growth factor-23 and disturbed vitamin D metabolism induced by an excessive phosphate load play a significant role in the development of cardiomyocyte hypertrophy and cardiac fibrosis. Recently, hyperphosphatemia was reported to promote de novo cholesterol synthesis in VSMCs and macrophages, which is likely to contribute to statin resistance in patients with end-stage kidney disease. This review outlines the association between increased phosphate load and coronary artery disease in patients with CKD.

Peripheral arterial disease in hemodialysis patients 10 years later

BACKGROUND AND OBJECTIVE

Patients with chronic kidney disease (CKD) on hemodialysis present high cardiovascular comorbidity. Peripheral arterial disease (PAD) is associated with higher mortality and the interest in its early detection and treatment is increasing. The objective of this study is to determine the frequency and severity of symptomatic PAD, and to establish its relationship with mortality in HD patients that have received treated early and compare them with a cohort of our center already reported.

MATERIAL AND METHODS

Retrospective study on a cohort of incident patients since 2014 and followed up until December 2019. Demographic data, cardiovascular risk, the presence of symptomatic PAD at baseline and during follow-up were collected. Trophic lesions were graded using the Rutherford scale.

RESULTS

Initially, there were 91 patients and 7 cases that were not included in the study were lost to follow-up. Age 64 ± 16 years, men 51.6% (47/91). The percentage of baseline PAD was 10.7% (9/84). During a median follow-up of 35 months (20-57), the diagnosis of PAD increased to 25% (21/84). Half of the patients with PAD 52.38% (11/21) obtained a score greater than 3 in the Rutherford Clinical Classification, which corresponds to severe disease. 13/21 patients required reoperation due to recurrence of symptoms (61.9% of cases with PAD). The development of PAD was significantly associated with: an elevated index of Charlson (3.9±2.1 vs. 7.7 ± 3.5; P = 0.001),being male (19 vs. 2; P = 0.001), diabetic (no: 7; yes: 15; P = 0.001) and with a history of chronic ischemic heart disease (no: 13; yes: 8; P = 0.001), 38.1% (8/21) had ischemic heart disease in patients who developed PAD, while in the absence of PAD the presence of ischemic heart disease was 9.5% (6/63). Furthermore, more than half (66.7% [14/21]) of those who developed PAD were diabetic. Univariate analysis showed that age, C reactive protein, albumin, and number of surgical interventions, but not PAD, were associated with mortality. In the multivariate analysis adjusted for other factors, only C reactive protein was related to overall survival Exp β: 2.17; P = 0.011; CI (1.19-3.97). Regarding cardiovascular mortality, in the multivariate Cox analysis, only PAD was related to mortality of cardiovascular origin Exp β: 1.73; P = 0.006; CI (1.17-2.56).

CONCLUSIONS

A significant number of patients on hemodialysis develop PAD requiring peripheral vascular surgery. PAD was not associated with overall mortality in our cohort, but it did show an association with cardiovascular mortality. Prospective studies with a larger sample size are necessary. New surgical treatments and Follow-up by vascular surgeons could improve the severity of PAD and the long-term prognosis.

Evaluation of Subclinical Vascular Disease in Diabetic Kidney Disease: A Tool for Personalization of Management of a High-Risk Population

Background: Patients with diabetic kidney disease (DKD) are at increased risk for cardiovascular events but traditional risk factors do not fully explain this association. Evaluation of subclinical vascular disease might improve risk stratification and management of these patients. The aim of the study was to compare the prevalence of markers of arterial stiffness, carotid atherosclerosis and peripheral arterial disease between patients with DKD and patients with type 2 diabetes mellitus (T2DM) and preserved kidney function. Methods: We prospectively enrolled patients with DKD and age- and gender-matched patients with T2DM but without DKD (estimated glomerular filtration rate < and ≥60 mL/min/1.73 m2, respectively). The presence of arterial stiffness was evaluated by measuring pulse wave velocity (PWV), augmentation index (AIx), AIx adjusted to a heart rate of 75 beats/min (AIx@75) and central systolic, diastolic, pulse and mean blood pressure. The presence of carotid atherosclerosis was evaluated by measuring carotid stenosis, carotid intima-media thickness and maximal plaque thickness. The presence of PAD was evaluated with the measurement of ankle-brachial index (ABI). Results: Forty patients with T2DM were included in the study (mean age 71.6 ± 8.9 years). The prevalence of cardiovascular risk factors was similar in patients with and without DKD. PWV was higher in the former (9.8 ± 5.5 and 6.6 ± 4.4 m/s, respectively; p < 0.05) and carotid stenosis of the left carotid artery was also greater in patients with DKD (36.5 ± 12.6 and 22.1 ± 17.2%, respectively; p < 0.05). Other markers of arterial stiffness and carotid atherosclerosis and ABI did not differ between patients with DKD and those without DKD. Conclusions: Patients with DKD appear to have more pronounced arterial stiffness and carotid atherosclerosis than patients with T2DM and preserved kidney function despite the similar prevalence of traditional cardiovascular risk factors in the two groups. Therefore, evaluating the presence of subclinical vascular disease in these patients could be a useful tool for the personalization of their management.

Carotid plaque thickness is increased in chronic kidney disease and associated with carotid and coronary calcification

BACKGROUND

Chronic kidney disease accelerates both atherosclerosis and arterial calcification. The aim of the present study was to explore whether maximal carotid plaque thickness (cPTmax) was increased in patients with chronic kidney disease compared to controls and associated with cardiovascular disease and severity of calcification in the carotid and coronary arteries.

METHODS

The study group consisted of 200 patients with chronic kidney disease stage 3 from the Copenhagen Chronic Kidney Disease Cohort and 121 age- and sex-matched controls. cPTmax was assessed by ultrasound and arterial calcification by computed tomography scanning.

RESULTS

Carotid plaques were present in 58% of patients (n = 115) compared with 40% of controls (n = 48), p = 0.002. Among participants with plaques, cPTmax (median, interquartile range) was significantly higher in patients compared with controls (1.9 (1.4-2.3) versus 1.5 (1.2-1.8) mm), p = 0.001. Cardiovascular disease was present in 9% of patients without plaques (n = 85), 23% of patients with cPTmax 1.0-1.9 mm (n = 69) and 35% of patients with cPTmax >1.9 mm (n = 46), p = 0.001. Carotid and coronary calcium scores >400 were present in 0% and 4%, respectively, of patients with no carotid plaques, in 19% and 24% of patients with cPTmax 1.0-1.9 mm, and in 48% and 53% of patients with cPTmax >1.9 mm, p<0.001.

CONCLUSIONS

This is the first study showing that cPTmax is increased in patients with chronic kidney disease stage 3 compared to controls and closely associated with prevalent cardiovascular disease and severity of calcification in both the carotid and coronary arteries.

Statin initiation and all-cause mortality in incident statin-naïve dialysis patients

BACKGROUND AND AIMS

Cardiovascular disease is the main cause of death in end-stage kidney disease (ESKD) patients. We aimed to explore the association between statin initiation after starting dialysis and all-cause mortality in statin-naïve ESKD patients.

METHODS

We analyzed nationwide claims data of incident dialysis patients from 2010 to 2017 in South Korea. Patients who had previous cardiovascular events or were administered statins before dialysis were excluded. The study group included dialysis patients receiving statins within 1 year after dialysis initiation. The control group was organized after propensity-score matching with age, sex, time of dialysis initiation, and underlying diabetes mellitus and hypertension. The main outcomes were all-cause mortality and major cardiovascular events.

RESULTS

We included 1596 patients who started statin treatment and 1:1 matched statin-nonusers. During the 9438 person-year follow-up, 468 deaths and 264 major adverse cardiovascular events (MACEs) occurred. Statin initiation was associated with a reduced risk of all-cause mortality (adjusted hazard ratio (aHR) 0.72, 95% confidence interval (CI) 0.60-0.87, p = 0.001), but not with MACE incidence (aHR 1.06, 95% CI 0.83-1.36, p = 0.62). In particular, patients prescribed the recommended dosage of statins according to the Kidney Disease Improving Global Outcomes guidelines showed the lowest mortality risk (aHR 0.55, 95% CI 0.40-0.75, p < 0.001).

CONCLUSIONS

Statin initiation was associated with lower risk of all-cause mortality in statin-naïve ESKD patients. As indication bias may be present in observational study setting, further prospective studies are warranted to validate the association of statin initiation with mortality in incident dialysis cases.

The Contribution of Known Familial Cardiovascular Disease Genes to Sudden Cardiac Death in Patients Undergoing Hemodialysis

INTRODUCTION

Patients with chronic kidney disease experience high rates of cardiovascular mortality and morbidity. When kidney disease progresses to the need for dialysis, sudden cardiac death (SCD) accounts for 25-35% of all cardiovascular deaths. The objective was to determine if rare genetic variants known to be associated with cardiovascular death in the general population are associated with SCD in patients undergoing hemodialysis.

METHODS

We performed a case-control study comparing 126 (37 African American [AfAn] and 89 European ancestry [EA]) SCD subjects and 107 controls (34 AfAn and 73 EA), matched for age, sex, self-reported race, dialysis duration (<2, 2-5 and >5 years), and the presence or absence of diabetes mellitus. To target the coding regions of genes previously reported to be associated with 15 inherited cardiac conditions (ICCs), we used the TruSight Cardio Kit (Illumina, San Diego, CA, USA) to capture the genetic regions of interest. In all, the kit targets 572-kb regions that include the protein-coding regions and 40-bp 5' and 3' end-flanking regions of 174 genes associated with the 15 ICCs. Using the sequence data, burden tests were conducted to identify genes with an increased number of variants among SCD cases compared to matched controls.

RESULTS

Eleven genes were associated with SCD, but after correction for multiple testing, none of the 174 genes were identified as having more variants in the SCD cases than the matched controls, including previously identified genes. Secondary burden tests grouping variants based on diseases and gene function did not produce statistically significant associations.

DISCUSSION/CONCLUSIONS

We found no associations between genes known to be associated with ICCs and SCD in our sample of patients undergoing hemodialysis. This suggests that genetic causes are unlikely to be a major pathogenic factor in SCD in hemodialysis patients, although our sample size limits definitive conclusions.

Usefulness of atherogenic index of plasma for estimating reduced eGFR risk: insights from the national health and nutrition examination survey

AIMS

Previous studies have identified Atherogenic index of plasma (AIP) as a simple measure of atherosclerosis. Because atherosclerosis plays a role in the development of renal damage, our study aims to evaluate the effect of AIP on the risk of reduced eGFR and assess its usefulness to refine the risk stratification of reduced estimated glomerular filtration rate (eGFR).

METHODS

Our study included 15,836 participants from the National Health and Nutritional Survey (NHANES) 2009-2016. Association was investigated by logistic regression. AIP was calculated as log (triglycerides/high-density lipoprotein cholesterol). Reduced eGFR was determined as eGFR < 60 ml/min per 1.73 m*2.

RESULTS

The prevalence of reduced eGFR was 8.01%. In the full model, each SD increase of AIP leaded to 27.4% additional risk for reduced eGFR. After dividing AIP into quartiles, the fourth quartile had a 1.649 times risk than the first quartile. Moreover, smooth curve fitting suggested that the risk of reduced eGFR elevated linearly with the increase of AIP. Subgroup analysis demonstrated that the association between AIP and reduced eGFR was robust in sex, body mass index, hypertension, and diabetes subpopulation, but the association was significantly stronger in black race and people aged less than 50 years old. Additionally, AUC displayed an advancement when introducing AIP into established risk factors (0.875 cs. 0.897, P < 0.001), category-free net reclassification index (0.249, 95% CI: 0.192-0.306, P < 0.001) and integrated discrimination index (0.007, 95% CI: 0.004-0.009, P < 0.001) also suggested the improvement from AIP.

CONCLUSION

The present work suggested a linear association between AIP and reduced eGFR. Furthermore, the results showed that the association was stronger in black race and people aged less than 50 years old. Most importantly, our work implicated the usefulness of AIP to refine the risk stratification of reduced eGFR.

Consensus document for ultrasound training in the specialty of Nephrology

Ultrasound is an essential tool in the management of the nephrological patient allowing the diagnosis, monitoring and performance of kidney intervention. However, the usefulness of ultrasound in the hands of the nephrologist is not limited exclusively to the ultrasound study of the kidney. By ultrasound, the nephrologist can also optimize the management of arteriovenous fistula for hemodialysis, measure cardiovascular risk (mean intimate thickness), implant central catheters for ultrasound-guided HD, as well as the patient's volemia using basic cardiac ultrasound, ultrasound of the cava inferior vein and lungs. From the Working Group on Interventional Nephrology (GNDI) of the Spanish Society of Nephrology (SEN) we have prepared this consensus document that summarizes the main applications of ultrasound to Nephrology, including the necessary basic technical requirements, the framework normative and the level of training of nephrologists in this area. The objective of this work is to promote the inclusion of ultrasound, both diagnostic and interventional, in the usual clinical practice of the nephrologist and in the Nephrology Services portfolio with the final objective of offering diligent, efficient and comprehensive management to the nephrological patient.

The impact of monocyte to high-density lipoprotein ratio on reduced renal function: insights from a large population

Aim: To investigate whether monocyte to HDL cholesterol ratio (MHR) can improve the risk stratification of reduced renal function by estimating atherosclerosis. Patients & methods: The cross-sectional study included 8159 subjects (males: 45.73%, mean age: 54.12 years) from Northeast China in 2013. Results: Each standard deviation increase of MHR brought 42.9% additional risk of reduced renal function in males. In females, MHR strongly correlated with reduced renal function before it reached a breakpoint (MHR = 0.25). Additionally, net reclassification improvement identified the value of MHR (0.199; 95% CI: 0.030–0.369; p = 0.021) to improve the risk classification of renal function reduction. Conclusion: This study implicates that MHR is independently associated with reduced renal function and can refine the risk stratification of renal function reduction.

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.

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.

Causes of Death in Patients with Severe Aortic Stenosis: An Observational study

Whether patients with severe aortic stenosis (AS) die because of AS-related causes is an important issue for the management of these patients. We used data from CURRENT AS registry, a Japanese multicenter registry, to assess the causes of death in severe AS patients and to identify the factors associated with non-cardiac mortality. We enrolled 3815 consecutive patients with a median follow-up of 1176 days; the 1449 overall deaths comprised 802 (55.3%) from cardiac and 647 (44.7%) from non-cardiac causes. Heart failure (HF) (25.7%) and sudden death (13.0%) caused the most cardiac deaths, whereas infection (13.0%) and malignancy (11.1%) were the main non-cardiac causes. According to treatment strategies, infection was the most common cause of non-cardiac death, followed by malignancy, in both the initial aortic valve replacement (AVR) cohort (N = 1197), and the conservative management cohort (N = 2618). Both non-cardiac factors (age, male, body mass index <22, diabetes, prior history of stroke, dialysis, anemia, and malignancy) and cardiac factors (atrial fibrillation, ejection fraction <68%, and the initial AVR strategy) were associated with non-cardiac death. These findings highlight the importance of close monitoring of non-cardiac comorbidities, as well as HF and sudden death, to improve the mortality rate of severe AS patients.

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 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.

Influence of Residual Renal Function in Carotid Modeling as a Marker of Early Atherosclerosis in Dialysis Patients

Atherosclerosis is frequently present in patients with chronic kidney disease (CKD) treated with dialysis. We evaluated the association between residual renal function (RRF), phosphate level, inflammation and other risk factors in carotid modeling as a marker of early atherosclerosis in peritoneal dialysis (PD) compared with hemodialysis (HD) patients. We studied 39 stable PD and 53 HD patients on renal replacement therapy (RRT) for 3 to 36 months duration. B-mode ultrasonography was used to determine carotid artery intima media thickness (CIMT). We classified patients with atherosclerosis if they have CIMT >10 mm and or presence of plaque. Out of our total dialysis population studied of 92 patients, 16.3% were diabetics and 57.6% were on hemodialysis. Expectedly, PD patients had a higher RRF (P < 0.001), 24 h urine volume (P < 0.001); C-reactive protein (P = 0.047), and a lower serum phosphate (P = 0.01), PTH (P < 0.05), alkaline phosphatase (P < 0.05), and albumin levels (P < 0.001) compared to hemodialysis patients. Atherosclerosis was found in 66.3% of patients and in 100% of a diabetic population. There was no significant difference in the presence of atherosclerosis between PD and HD patients [56.4 vs 73.6% HD, respectively]. Multiple regression analysis showed age, diabetes, HD modality, RRF, phosphate, PTH and pulse pressure as independent parameters associated with atherosclerosis. Apart from the traditional risk factors like age and diabetes, our study showed a link of atherosclerosis with metabolic abnormalities secondary to renal failure. We demonstrated a novel, independent association between RRF and atherosclerosis, underlining the importance of preservation of the RRF in dialysis patients.

Association between serum 25-hydroxyvitamin D levels and carotid atherosclerosis in chronic kidney disease patients

Background

Epidemiological studies have shown an inverse relationship between vitamin D levels and cardiovascular diseases. However, this does not infer a causal relationship between the two. Chronic kidney disease (CKD) patients have a high prevalence of vitamin D deficiency and carotid atherosclerosis. Therefore, in this study we have aimed to determine the association between serum 25-hydroxyvitamin D levels and carotid atherosclerosis in the CKD population.

Methods

100 CKD stage 3–4 patients were included in the study. Direct chemiluminesent immunoassay was used to determine the level of serum 25-hydroxyvitamin D. All subjects underwent a carotid ultrasound to measure common carotid artery intima-media thickness (CCA-IMT) and to assess the presence of carotid plaques or significant stenosis (≥50 %). Vitamin D deficiency was defined as serum 25-hydroxyvitamin D < 25 nmol/L. Abnormal CCA-IMT was defined as CCA-IMT ≥ 0.8 mm. Plaque was defined as a focal structure that encroaches into the arterial lumen of ≥ 0.5 mm or 50 % of the surrounding IMT value. Significant stenosis was defined as peak-systolic velocities ≥ 125 cm/s and end-diastolic velocities ≥ 40 cm/s.

Results

The vitamin D deficiency and non-deficiency groups did not differ significantly in terms of abnormal CCA-IMT (P = 0.443), carotid plaque (P = 0.349), and carotid stenosis (P = 0.554). No significant correlation between serum 25-hydroxyvitamin D levels and CCA-IMT (P = 0.693) was found. On a backward multiple linear regression model, serum 25-hydroxyvitamin D levels was not associated with CCA-IMT, abnormal CCA-IMT, or plaque presence.

Conclusions

No important association between serum 25-hydroxyvitamin levels and carotid atherosclerosis was found in CKD patients.

Chronic Kidney Disease and Carotid Atherosclerosis in Patients With Acute Stroke

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD) is increasingly recognized as an independent risk factor for cardiovascular disease and stroke. Our aim was to examine the association between estimated glomerular filtration rate (eGFR) and carotid plaques, stenosis and occlusions, and to assess whether CKD and its severity affect carotid atherosclerosis in a cohort of unselected patients with acute stroke.

METHODS

A total of 249 consecutive patients with acute stroke (ischemic or hemorrhagic) were included in this study and baseline eGFR, carotid intima-media thickness (cIMT), and carotid stenosis were evaluated. The eGFR was calculated using the modified Modification of Diet in Renal Disease equation, which was adjusted for data from Chinese CKD patients. An eGFR rate of <60 mL/min/1.73 m was defined as CKD. The cIMT and carotid plaques were detected by carotid ultrasound.

RESULTS

CKD, defined as eGFR<60 mL/min/1.73 m, was found in 66 individuals (26.50%). Among the 5 subtypes, the level of low-density lipoprotein cholesterol was significantly higher in the moderate and severe stenosis groups compared with the normal, elevated cIMT and mild stenosis groups (P<0.01). The value of eGFR gradually decreased with increasing degree of carotid stenosis, and the differences between the groups were statistically significant (P<0.01). On linear regression analysis, eGFR was negatively correlated with the degree of carotid stenosis (r=0.03; P<0.05). On ordinal logistic regression analysis, eGFR was an independent risk factor associated with carotid atherosclerosis (1.05; 95% confidence interval, 0.47-1.63).

CONCLUSIONS

There was a significant burden of atherosclerosis among individuals with CKD. CKD is an independent predictor of carotid plaques, stenoses, and occlusions in patients with acute stroke.

Matrix Metalloproteinases and Subclinical Atherosclerosis in Chronic Kidney Disease: A Systematic Review

Background. Cardiovascular disease (CVD) remains a significant problem in Chronic Kidney Disease (CKD). Subclinical atherosclerosis identified by noninvasive methods could improve CVD risk prediction in CKD but these methods are often unavailable. We therefore systematically reviewed whether circulating levels of Matrix Metalloproteinases (MMPs) and tissue inhibitors (TIMPs) are associated with subclinical atherosclerosis in CKD, as this would support their use as biomarkers or pharmacologic targets. Methods. All major electronic databases were systematically searched from inception until May 2015 using appropriate terms. Studies involving CKD patients with data on circulating MMPs levels and atherosclerosis were considered and subjected to quality assessment. Results. Overall, 16 studies were identified for qualitative synthesis and 9 studies were included in quantitative synthesis. MMP-2 and TIMP-1 were most frequently studied while most studies assessed carotid Intima-Media Thickness (cIMT) as a measure of subclinical atherosclerosis. Only MMP-2 demonstrated a consistent positive association with cIMT. Considerable variability in cIMT measurement methodology and poor plaque assessment was found. Conclusions. Although MMPs demonstrate great potential as biomarkers of subclinical atherosclerosis, they are understudied in CKD and not enough data existed for meta-analysis. Larger studies involving several MMPs, with more homogenized approaches in determining the atherosclerotic burden in CKD, are needed.

Predictors of Subclinical Atheromatosis Progression over 2 Years in Patients with Different Stages of CKD

BACKGROUND AND OBJECTIVES

Ultrasonographic detection of subclinical atheromatosis is a noninvasive method predicting cardiovascular events. Risk factors predicting atheromatosis progression in CKD are unknown. Predictors of atheromatosis progression were evaluated in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our multicenter, prospective, observational study included 1553 patients with CKD (2009-2011). Carotid and femoral ultrasounds were performed at baseline and after 24 months. A subgroup of 476 patients with CKD was also randomized to undergo ultrasound examination at 12 months. Progression of atheromatosis was defined as an increase in the number of plaque territories analyzed by multivariate logistic regression.

RESULTS

Prevalence of atheromatosis was 68.7% and progressed in 59.8% of patients after 24 months. CKD progression was associated with atheromatosis progression, suggesting a close association between pathologies. Variables significantly predicting atheromatosis progression, independent from CKD stages, were diabetes and two interactions of age with ferritin and plaque at baseline. Given that multiple interactions were found between CKD stage and age, phosphate, smoking, dyslipidemia, body mass index, systolic BP (SBP), carotid intima-media thickness, plaque at baseline, uric acid, cholesterol, 25-hydroxy vitamin D (25OH vitamin D), and antiplatelet and phosphate binders use, the analysis was stratified by CKD stages. In stage 3, two interactions (age with phosphate and plaque at baseline) were found, and smoking, diabetes, SBP, low levels of 25OH vitamin D, and no treatment with phosphate binders were positively associated with atheromatosis progression. In stages 4 and 5, three interactions (age with ferritin and plaque and plaque with smoking) were found, and SBP was positively associated with atheromatosis progression. In dialysis, an interaction between body mass index and 25OH vitamin D was found, and age, dyslipidemia, carotid intima-media thickness, low cholesterol, ferritin, and uric acid were positively associated with atheromatosis progression.

CONCLUSIONS

Atheromatosis progression affects more than one half of patients with CKD, and predictive factors differ depending on CKD stage.

Alteration of cardiovascular structure and function in patients undergoing peritoneal dialysis

AIMS

Cardiovascular alterations contribute to a high mortality rate in patients with end-stage renal disease (ESRD). The aims of the present study are to evaluate left ventricular (LV) function and common carotid artery (CCA) parameters and to determine risk factors associated with these changes in patients undergoing peritoneal dialysis (PD).

METHODS

This longitudinal prospective study was conducted in 50 ESRD patients in whom PD had been initiated and who were observed for 18 months after the commencement of dialysis treatment, with echocardiography and CCA ultrasound parameter evaluation.

RESULTS

LV hypertrophy was observed in 78% of patients at baseline and in 60% after 18 months of PD treatment. LV systolic and diastolic function was found to be significantly better after 18 months of PD treatment. Examining predictors of LV systolic function, it was found that total cholesterol was an independent positive predictor and endothelin-1 (ET-1) an independent negative predictor of LV systolic function after 18 months of treatment with PD (p < 0.001). Independent negative predictors of diastolic LV function were hemoglobin and type 2 diabetes mellitus, and daily collection of urine was an independent positive predictor (p < 0.001). Female gender was an independent negative predictor of CCA intima-media thickness, whereas body mass index, ET-1 and C-reactive protein were independent positive predictors (p < 0.001).

CONCLUSIONS

The results suggest several novel modifiable mechanisms related to the short-term effects of dialysis that are potentially implicated in the development of uremic cardiomyopathy.

Changes over the last decade in carotid atherosclerosis in patients with end-stage kidney disease

OBJECTIVE

Therapies for chronic kidney disease have changed greatly over the last decade. The aim of this study was to examine the changes in the clinical characteristics and carotid atherosclerosis of patients with end-stage kidney disease (ESKD) over the last 9 years.

METHODS

A cross-sectional study of 150 consecutive patients with ESKD who had initiated maintenance dialysis between January 2005 and December 2013 was conducted. The patients' mean age was 68 ± 13 years. The group comprised 73% men, and 63% of the patients had diabetic nephropathy. The carotid artery-intima media thicknesses and the plaque scores (PS) were measured using carotid artery ultrasonography within 3 months of dialysis initiation. Changes in the patients' carotid atherosclerosis and clinical characteristics over the years were examined by categorizing the patients into 3 groups representing 3-year intervals based on when dialysis was initiated.

RESULTS

The PS declined from 12.8 to 5.4 (P = 0.001). Low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol levels declined over the 9-year period (P = 0.005 and P = 0.006, respectively), and the ratio of statin users increased markedly from 24% to 54% (P = 0.001). Univariate regression analysis identified a positive correlation between the PS and LDL-C (r = 0.281; P = 0.01), and a strong positive correlation was found between the PS and LDL-C after adjusting for various risk factors for atherosclerosis.

CONCLUSION

Carotid atherosclerosis in patients with ESKD has decreased over the past 9 years, which may be a consequence of improvements in dyslipidemia management.

Association of serum phosphorus with subclinical atherosclerosis in chronic kidney disease. Sex makes a difference

BACKGROUND

Cardiovascular disease is the leading cause of mortality in chronic kidney disease (CKD). Serum phosphate has been associated to cardiovascular disease in the general population and this effect seems to be different according to sex. In the present study we analyze the effect of phosphate on subclinical atherosclerosis in the NEFRONA population and its effect depending on sex.

DESIGN

Carotid ultrasound assessing the presence of plaques was performed by an itinerant team in 1687 CKD patients not in dialysis without previous cardiovascular events. Standard blood test and anthropometrical parameters were also recorded.

RESULTS

Multivariate linear regression to model phosphate levels in patients with CKD showed an interaction of sex with age. Thus, among men, serum phosphate levels declined significantly with age almost linearly. Serum phosphate levels in women under the age of 40-45 years overlapped with those in men and then stayed above, showing and overall constant relationship. Multivariate logistic regression analysis showed that higher phosphate levels associated with a higher risk of presenting atheromatous plaque. This risk however was different according to sex. In men, phosphate levels within the normal range associated with an increased risk of subclinical atheromatosis whereas in women this risk only increased with serum levels over the normal range.

CONCLUSIONS

This study demonstrates that phosphate levels are associated with the presence of subclinical atheromatosis in a large CKD population. This effect of phosphate on subclinical atheromatosis was different according to sex, suggesting that a recommended serum phosphate levels could be different for male than for female CKD patients.

Observational multicenter study to evaluate the prevalence and prognosis of subclinical atheromatosis in a Spanish chronic kidney disease cohort: baseline data from the NEFRONA study

BACKGROUND

Cardiovascular events (CVE) are more prevalent in chronic kidney disease (CKD) than in general population, being the main cause of morbimortality. Specific risk factors related to CKD have been suggested, because traditional factors do not fully explain this increase in cardiovascular disease rates. However, the role of atheromatosis, its pathogenesis and evolution are still unclear. The potential use of diagnostic tests to detect subclinical atheromatosis has to be determined.

METHODS

NEFRONA is a prospective multicenter cohort study. 2445 CKD subjects were enrolled from 81 Spanish hospitals and dialysis clinics, from 2010 to 2012. Eligibility criteria included: 18 to 74 years old, CKD stage 3 or higher, and no previous CVE. 559 non-CKD controls were also recruited. Demographical, clinical and analytical data were collected. Carotid and femoral ultrasounds were performed by a single trained team to measure carotid intima-media thickness (cIMT) and detect atheromatous plaques. Ankle-brachial index (ABI) was measured.

RESULTS

Differences in age, sex and prevalence and control of cardiovascular risk factors were found between controls and CKD patients. These differences are similar to those described in epidemiological studies.No difference was found regarding cIMT between controls and CKD (when subjects with plaques in common carotid arteries were omitted); earlier CKD stages had higher values. CKD patients had a higher rate of atheromatous plaques, with no difference between stages in the unadjusted analysis. A group of patients had plaques in femoral arteries but were plaque-free in carotid arteries, and would have gone underdiagnosed without the femoral study. The percentage of pathologic ABI was higher in CKD, with higher prevalence in more advanced stages, and a higher rate of ABI >1.4 than <0.9, suggesting more vascular calcification.

CONCLUSIONS

NEFRONA is the first large study describing the actual prevalence of subclinical atheromatosis across different CKD stages. There is a very high rate of atheromatous plaques and pathologic ABI in CKD. Prospective data will add important information to the pathogenesis and evolution of atheromatosis in CKD, compared to non-CKD subjects.

The relationship between AASI and arterial atherosclerosis in ESRD patients

OBJECTIVE

To explore the relationship between ambulatory blood pressure and arterial atherosclerosis and provide simple and easy reference indicators for the prediction, prevention and prognosis of cardiovascular events in end-stage renal disease (ESRD) patients.

METHOD

This prospective study consecutively collected clinical data of 114 ESRD hospitalized patients in the Department of Nephrology, the First Affiliated Hospital of Nanjing Medical University during August 2012 to December 2012. The data included laboratory data, the ambulatory blood pressure monitoring (ABPM), carotid ultrasound, two-dimensional echocardiography and the prognosis scores of the death risk.

RESULTS

(1) A series of ABPM parameters were closely associated with atherosclerosis (p ≤ 0.05). Ambulatory Arterial Stiffness Index (AASI) was the most representative parameter of ABPM and also the best indicator for atherosclerosis (logistic regression analysis, p = 0.005). (2) AASI was a comprehensive index of atherosclerosis (p < 0.001), which was associated with the increase of left ventricular diameter (p = 0.028) and the risk of death (p < 0.001). The independent risk factors of AASI were the growth of the age (p < 0.001), elevated serum fibrinogen (p = 0.009) and reduced serum albumin (p = 0.022).

CONCLUSION

AASI, as the representative of ABPM parameters, related well to atherosclerosis, which implied a broader application of ABPM in ESRD patients.

Lack of vitamin D receptor causes stress-induced premature senescence in vascular smooth muscle cells through enhanced local angiotensin-II signals

OBJECTIVES

The inhibition of the renal renin-angiotensin system by the active form of vitamin D contributes to the cardiovascular health benefits of a normal vitamin D status. Local production of angiotensin-II in the vascular wall is a potent mediator of oxidative stress, prompting premature senescence. Herein, our objective was to examine the impact of defective vitamin D signalling on local angiotensin-II levels and arterial health.

METHODS

Primary cultures of aortic vascular smooth muscle cells (VSMC) from wild-type and vitamin D receptor-knockout (VDRKO) mice were used for the assessment of cell growth, angiotensin-II and superoxide anion production and expression levels of cathepsin D, angiotensin-II type 1 receptor and p57(Kip2). The in vitro findings were confirmed histologically in aortas from wild-type and VDRKO mice.

RESULTS

VSMC from VDRKO mice produced more angiotensin-II in culture, and elicited higher levels of cathepsin D, an enzyme with renin-like activity, and angiotensin-II type 1 receptor, than wild-type mice. Accordingly, VDRKO VSMC showed higher intracellular superoxide anion production, which could be suppressed by cathepsin D, angiotensin-II type 1 receptor or NADPH oxidase antagonists. VDRKO cells presented higher levels of p57(Kip2), impaired proliferation and premature senescence, all of them blunted upon inhibition of angiotensin-II signalling. In vivo studies confirmed higher levels of cathepsin D, angiotensin-II type 1 receptor and p57(Kip2) in aortas from VDRKO mice.

CONCLUSION

The beneficial effects of active vitamin D in vascular health could be a result of the attenuation of local production of angiotensin-II and downstream free radicals, thus preventing the premature senescence of VSMC.

The relationship between renal resistive index, arterial stiffness, and atherosclerotic burden: the link between macrocirculation and microcirculation

The renal resistive index (RRI) measured by Doppler sonography is a marker of microvascular status that can be generalized to the whole of the arterial tree. Its association with large-vessel dysfunction, such as arterial stiffness or the atherosclerotic burden, can help to establish physiopathological associations between macrocirculation and microcirculation. The authors conducted a cross-sectional study of hypertensive patients (n=202) and a healthy control group (n=16). Stiffness parameters, atherosclerotic burden, and determination of the RRI in both kidneys were performed. The average RRI was 0.69±0.08 and was significantly greater in patients with diabetes and chronic kidney disease. Renal resistive index positively correlated with age, creatinine, and albuminuria. Positive correlations were found with arterial stiffness parameters (pulse wave velocity, ambulatory arterial stiffness index, and 24-hour pulse pressure), as well as atherosclerotic burden and endothelial dysfunction measured as asymmetric dimethylarginine in serum. In the multivariate analysis, independent factors for increased RRI were age, renal function, 24-hour diastolic blood pressure, and arterial stiffness. The authors concluded that there is an independent association between renal hemodynamics and arterial stiffness. This, together with the atherosclerotic burden and endothelial dysfunction, suggests that there is a physiopathologic relationship between macrovascular and microvascular impairment.

Biomarkers of cardiovascular remodeling in patients on peritoneal dialysis

OBJECTIVES

The purpose of this study was to determine endothelin (ET)-1 and nitric oxide (NO) serum concentration levels at baseline and after 1 year of peritoneal dialysis (PD) treatment. A further aim was to evaluate the association between ET-1 and NO with parameters of echocardiography and the common carotid artery (CCA) ultrasound, and to assess their impact on cardiovascular remodeling. We also aimed to evaluate the influence of dialysis adequacy and residual renal function (RRF) on cardiovascular remodeling.

METHODS

This study included 40 PD patients in whom we measured serum ET-1 and NO concentrations, echocardiography and CCA ultrasound parameters.

RESULTS

ET-1 decreased and NO serum concentration levels increased (p < 0.01) after 12 months of PD treatment compared to baseline values. Left ventricular (LV) hypertrophy was observed in 77.5% of patients at baseline with significant reduction in LV mass index (LVMI), CCA intima media thickness (IMT) and plaque score after 12 months of PD treatment (p < 0.001). The dialysis adequacy and RRF were significantly associated with LVMI and CCA IMT after 12 months on PD.

CONCLUSION

In our study, ET-1 significantly decreased while NO increased during PD treatment and both were independently related to the cardiovascular remodeling parameters in PD patients.

Impact of peritoneal dialysis treatment on arterial stiffness and vascular changes in diabetic type 2 and nondiabetic patients with end-stage renal disease

Diabetes mellitus (DM) is the leading cause of the end-stage renal disease (ESRD). Vascular diseases are the most common cause of morbidity and mortality in the chronic kidney disease. The aim of this study was to analyze the impact of peritoneal dialysis (PD) treatment on morphologic and hemodynamic vascular parameters of carotid arteries in diabetic type 2 and nondiabetic patients with ESRD during the period of one year after the start of PD treatment using ultrasonography of carotid arteries and their relation on uremia and PD inherent factors. Mean intima-media thickness, plaque score, peak systolic velocity, end-diastolic velocity, and carotid diameter significantly decreased 12 months after PD treatment start in both groups. Significant reduction in median serum endothelin-1 concentration after 12 months on PD treatment was observed in the group of patients with DM (7.6–5.9 pg/mL) and also in group of patients without DM (3.6–3.3 pg/mL). Also median nitric oxide concentration significantly increased after 12 months on PD compared to baseline levels both in patients with DM (25.0–34.3 μmol/L) as was observed in patients without DM (49.6–56.5 μmol/L). PD treatment, with the regulation of these vasoactive molecules and other vascular risk factors, significantly contributes to vascular remodeling, especially in DM patients.

The role of carotid ultrasound in assessing carotid atherosclerosis in individuals at low-to-intermediate cardiovascular risk

INTRODUCTION AND OBJECTIVES

Detection of carotid atherosclerosis might help to better identify individuals susceptible to cardiovascular events. We aimed to quantify the number of participants with carotid atherosclerosis and low-to-intermediate cardiovascular risk according to the traditional risk factor scoring, and therefore with an elevated risk of cardiovascular events.

METHODS

Cross-sectional, observational study performed during a cardiovascular screening program. From a total of 3778 volunteers, low-to-intermediate cardiovascular risk individuals (N=2354) were identified and studied. Physical examination, blood test, and carotid ultrasound followed standard procedures. Common, bulb, and internal carotid arteries were examined and common carotid intima-media thickness was measured. SCORE risk value was calculated for all participants. Univariate and multivariate statistical analysis was performed.

RESULTS

Mean age of participants was 58.9 (15) years, 43.8% were men, 23.7% had hypertension, and 20.5% had hypercholesterolemia. The mean SCORE value was 1.47 (1.4). Both carotid intima-media thickness and the prevalence of carotid plaques increased steadily and significantly (P<.005) as advanced decades of life were analyzed. Variables significantly related with the presence of carotid atherosclerosis were age, male sex, and systolic blood pressure. Interestingly, 592 (25.1%) individuals were reclassified to a higher risk due to the presence of carotid atherosclerosis.

CONCLUSIONS

There was a clear dissociation between cardiovascular risk scoring and the presence of atherosclerosis, because 1 of 4 study participants at low-to-intermediate cardiovascular risk had carotid atherosclerosis.

A low fractional excretion of Phosphate/Fgf23 ratio is associated with severe abdominal Aortic calcification in stage 3 and 4 kidney disease patients

BACKGROUND

Vascular calcification (VC) contributes to high mortality rates in chronic kidney disease (CKD). High serum phosphate and FGF23 levels and impaired phosphaturic response to FGF23 may affect VC. Therefore, their relative contribution to abdominal aortic calcification (AAC) was examined in patients CKD stages 3-4.

METHODS

Potential risk factors for AAC, measured by the Kauppila Index (KI), were studied in 178 patients.

RESULTS

In multivariate linear analysis, AAC associated positively with age, male gender, CKD-stage, presence of carotid plaques (CP) and also with FGF23, but negatively with fractional excretion of phosphate (FEP). Intriguingly, FEP increased with similar slopes with elevations in PTH, with reductions in GFR, and also with elevations in FGF23 but the latter only in patients with none (KI = 0) or mild (KI = 1-5) AAC. Lack of a FEP-FGF23 correlation in patients with severe AAC (KI > 5) suggested a role for an impaired phosphaturic response to FGF23 but not to PTH in AAC. Logistic and zero-inflated analysis confirmed the independent association of age, CKD stage, male gender and CP with AAC, and also identified a threshold FEP/FGF23 ratio of 1/3.9, below which the chances for a patient of presenting severe AAC increased by 3-fold. Accordingly, KI remained unchanged as FEP/FGF23 ratios decreased from 1/1 to 1/3.9 but markedly increased in parallel with further reductions in FEP/FGF23 < 1/3.9.

CONCLUSIONS

In CKD 3-4, an impaired phosphaturic response to FGF23 with FEP/FGF23 < 1/3.9 associates with severe AAC independently of age, gender or CP.

Common carotid wall shear stress and carotid atherosclerosis in end-stage renal disease patients

Decrease of arterial wall shear stress (WSS) is associated with higher probability of atherosclerotic plaque development in many disease conditions. End-stage renal diseases (ESRD) patients suffer from vascular disease frequently, but its nature differs from general population. This study was aimed at proving an association between common carotid wall shear stress and the presence of carotid bifurcation plaques in a group of ESRD patients. ESRD subjects, planned for the creation of a dialysis access and therapy were included. Wall shear rate (WSR) was used as a surrogate of WSS and was analyzed in the common carotid arteries by duplex ultrasonography. Intima media thickness (IMT) was measured at the same site. The presence/absence of carotid bifurcation plaques was recorded. The endothelial function was estimated by the levels of von Willebrand factor (vWf). 35 ESRD patients were included (19 females, 17 diabetics). Atherosclerotic plaque was present in 53 % of bifurcations. Wall shear rate was lower in arteries with plaques (349+/-148 vs. 506+/-206 s(-1), p=0.005) and was directly related to the height of IMT and inversely to the activity of vWf (r= -0.65, p=0.016). Lower wall shear rate in the common carotid arteries is linked to the endothelial dysfunction and to the presence of atherosclerotic plaques in carotid bifurcations in ESRD subjects. Faster arterial dilatation may facilitate this process in ESRD subjects.

Endothelial dysfunction in uremic patients on continuous ambulatory peritoneal dialysis (CAPD)

Endothelial dysfunction is associated with diabetic micro- and macroangiopathy as well as with the decline in creatinine clearance. It has been suggested that endothelial dysfunction presents in patients (pts) on continuous ambulatory peritoneal dialysis (CAPD). The objective of this study was to examine the plasma biomarkers of endothelial dysfunction and their association with IMT of carotid arteries in diabetic and non-diabetic patients on CAPD. This study included 37 CAPD pts (25 with type II diabetes and 12 non-diabetic pts) mean age 59.2 years ± 2.48. Plasma von Willebrand factor (vWF) activity, serum albumin, glucose, total cholesterol, triglycerides and lipoprotein (a) levels, as well as serum level of homocysteine, parathyroid hormone (PTH) in plasma and microalbuminuria was determined. Ultrasound examination of carotid arteries was performed in all patients by measured bilateral intima-media thickness of carotid artery (CIMT). Mean IMT value was significantly higher in type 2 DM patients (0.86 ± 0.04 mm) compared to non-diabetic patients (0.52 ± 0.06 mm) on peritoneal dialysis (p<0.0001). There was also a significant difference in lipids /triglycerides and Lp (a)/, procoagulation (fibrinogen, von Wilebrand factor, factor VIII) and inflammatory markers (CRP) level between type 2 DM and non-diabetic CAPD patients. A stepwise multiple regression analysis revealed that log triglycerides and factor VIII were independent factors for the IMT. The results of this research impose that diabetic type 2 CAPD patients have developed systemic alteration of endothelial function and higher risk of cardiovascular complications compared to non-diabetic CAPD patients.

Adults with late stage 3 chronic kidney disease are at high risk for prevalent silent brain infarction: a population-based study

BACKGROUND AND PURPOSE

The close relationship between stroke and chronic kidney disease (CKD) has been well-documented. However, few studies have focused on silent brain infarction (SBI) in CKD. We investigated the prevalence of SBI in different stages of CKD.

METHODS

We included 1312 participants aged 30 to 93 years who came from either a random sample of residents or from a group of physically examined subjects in the same community. Basic information, clinical evaluations, laboratory tests, and MRI images were assessed. Subjects were divided into groups 1, 2, 3a, and 3b, corresponding to the estimated glomerular filtration rate (eGFR) levels of ≥ 90.0, 60.0 to 89.9, 45.0 to 59.9, and 30.0 to 44.9 mL/min/1.73 m².

RESULTS

The crude prevalence was 4.7%: 2.6% (20 of 759 subjects) in group 1; 6.3% (32 of 506) in group 2; 12.9% (4 of 31) in group 3a; and 37.5% (6 of 16) in group 3b (P<0.001). Additionally, SBI also correlated with age, male sex, hypertension, diabetes, moderate carotid plaque, higher blood pressures, obesity, and levels of triglyceride, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and uric acid (all P<0.05). The effects for SBI risk in each eGFR group versus group 1 did not increase except for group 3b (OR, 9.34; P<0.001).

CONCLUSIONS

A close association exists between SBI and eGFR. We have found a significant increase in prevalence of SBI when eGFR is between 30.0 and 44.9 mL/min/1.73 m². Adults with late stage 3 CKD are at high risk for prevalent SBI.

Association of chronic kidney disease with muscle deficits in children

The effect of chronic kidney disease (CKD) on muscle mass in children, independent of poor growth and delayed maturation, is not well understood. We sought to characterize whole body and regional lean mass (LM) and fat mass (FM) in children and adolescents with CKD and to identify correlates of LM deficits in CKD. We estimated LM and FM from dual energy x-ray absorptiometry scans in 143 children with CKD and 958 controls at two pediatric centers. We expressed whole body, trunk, and leg values of LM and FM as Z-scores relative to height, sitting height, and leg length, respectively, using the controls as the reference. We used multivariable regression models to compare Z-scores in CKD and controls, adjusted for age and maturation, and to identify correlates of LM Z-scores in CKD. Greater CKD severity associated with greater leg LM deficits. Compared with controls, leg LM Z-scores were similar in CKD stages 2 to 3 (difference: 0.02 [95% CI: -0.20, 0.24]; P = 0.8), but were lower in CKD stages 4 to 5 (-0.41 [-0.66, -0.15]; P = 0.002) and dialysis (-1.03 [-1.33, -0.74]; P < 0.0001). Among CKD participants, growth hormone therapy associated with greater leg LM Z-score (0.58 [0.03, 1.13]; P = 0.04), adjusted for CKD severity. Serum albumin, bicarbonate, and markers of inflammation did not associate with LM Z-scores. CKD associated with greater trunk LM and FM, variable whole body LM, and normal leg FM, compared with controls. In conclusion, advanced CKD associates with significant deficits in leg lean mass, indicating skeletal muscle wasting. These data call for prospective studies of interventions to improve muscle mass among children with CKD.

Large artery calcification on dialysis patients is located in the intima and related to atherosclerosis

BACKGROUND AND OBJECTIVES

Vascular calcification (VC) has a significant effect in cardiovascular diseases on dialysis patients. However, VC is assessed with x-ray-based techniques, which do not inform about calcium localization (intima, media, atherosclerosis-related). The aim of this work is to study VC and its related factors using arterial ultrasound to report the exact location of calcium.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational, cross-sectional, case-control study that included 232 patients in dialysis and 208 age- and sex-matched controls with normal kidney function. Demographic data and laboratory values were collated. Carotid, femoral, and brachial ultrasounds were performed to assess VC and atherosclerosis burden using a standardized protocol.

RESULTS

Cardiovascular risk factors were predominantly found in controls, although the burden of atherosclerosis was higher in the dialysis group. VC was significantly more prevalent in the group of patients on dialysis than control subjects, and in both groups the most prevalent pattern of VC was linear calcification located in the intima of the artery wall. Age and undergoing dialysis (with or without previous cardiovascular diseases) were positively and significantly associated with linear calcification. Conversely, the absence of atherosclerosis and low levels of C-reactive protein and phosphorus significantly impeded the development of linear calcification.

CONCLUSIONS

VC in large, conduit arteries is more prevalent in patients on dialysis than controls and is predominantly located in a linear fashion in the intima of the arteries.

Atherosclerosis in CKD: differences from the general population

The prevalence of cardiovascular morbidity and mortality is higher in patients with chronic kidney disease (CKD)-especially those with end-stage renal disease-than in the general population. The contribution of atherosclerosis to cardiovascular disease in patients with CKD remains unclear. Researchers in the 1970s proposed that atherosclerosis was the main cause of cardiovascular disease in patients with CKD and that its progression, based on observations of patients on long-term dialysis, was accelerated by the uremic state. Subsequent reports, however, favor the involvement of other mechanisms, such as arteriosclerosis (characterized by vascular stiffening), vascular calcification, 'myocyte/capillary mismatch', congestive cardiomyopathy, and sudden cardiac death. Imaging and morphological studies have contributed to our understanding of the pathogenesis and progression of cardiovascular disease associated with CKD. Based on clinical and experimental findings, we hypothesize the following: the initial cardiovascular abnormalities in the CKD setting include arteriosclerosis, left ventricular diastolic dysfunction, and left ventricular hypertrophy, abnormalities which, in adult patients, are often accompanied by atherosclerosis. The prevalence of atherosclerosis increases with age and is aggravated, but not specifically induced, by CKD. The cardiovascular events associated with atherosclerosis are more often fatal in patients with CKD than in individuals without CKD.

Serum levels of matrix metalloproteinase-10 are associated with the severity of atherosclerosis in patients with chronic kidney disease

Cardiovascular disease is the leading cause of mortality in chronic kidney disease (CKD). As matrix metalloproteinases have a major role in atherosclerosis, we hypothesized that alterations in metalloproteinases-8, -10 and their tissue inhibitor-1 can be associated with the severity of atherosclerosis in patients with kidney disease. This was evaluated in a cross-sectional, observational study of 111 patients with stages I-V kidney disease, 217 patients on dialysis and 50 healthy controls. The severity of atherosclerosis was estimated with the atherosclerosis score (AS), combining the results of ankle-brachial index and carotid ultrasound. Serum levels of the two metalloproteinases and tissue inhibitor-1 were measured by enzyme-linked immunosorbent assay and were significantly increased in patients with kidney disease compared with the healthy controls, and higher in patients on dialysis than in earlier stages of CKD. The severity of the AS was also more prevalent in the dialysis group, in which serum levels of both metalloproteinases and tissue inhibitor-1 were significantly higher. After multivariate analysis, metalloproteinase-10, dialysis, C-reactive protein, age, and male gender were associated with increased risk of atherosclerosis. Thus, patients with CKD exhibit elevated levels of circulating metalloproteinase-10, and this was independently associated with the severity of atherosclerosis and may represent a new biomarker of atherosclerotic diseases.