High-resolution B-mode ultrasonography in evaluation of atherosclerosis in uremia

Subclinical atherosclerosis in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis is an inflammatory disorder of the central nervous system. Inflammation may create high susceptibility to subclinical atherosclerosis. The purpose of this study was to compare subclinical atherosclerosis and the role of inflammatory cytokines between the group of patients with relapsing-remitting multiple sclerosis (RRMS) and healthy controls matched for age and sex.

METHODS

The study group consisted of 112 non-diabetic and non-hypertensive RRMS patients treated with disease modifying drugs (DMD) and the control group was composed of 51 healthy subjects. The common carotid artery (CCA) intima media thickness (IMT) was investigated. Serum levels of risk factors for atherosclerosis and inflammatory cytokines were also determined.

RESULTS

The mean CCA IMT (0.572 ± 0.131 mm vs. 0.571 ± 0.114 mm) did not differ (p > 0.05) between patients and controls. The RRMS patients' CCA IMT was significantly correlated with serum interleukin 6 (IL-6) (p = 0.027), high-sensitivity C-reactive protein (hs-CRP) (p = 0.027), cystatin C (p < 0.0005), glucose (p = 0.031), cholesterol (p = 0.008), LDL (p = 0.021), erythrocyte sedimentation rate (p = 0.001) and triglyceride (p = 0.018) level. We fitted generalized linear models in order to assess the relationship between CCA IMT and IL‑6 with adjustment for sex and age. The obtained results showed that adjusted for age (p < 0.001) and sex (p = 0.048) IL‑6 serum levels statistically significantly (p = 0.009) predict CCA IMT only in the RRMS group.

CONCLUSION

The findings of the present study suggest that when treated with DMD RRMS might not be an independent risk factor for early atherosclerosis presenting with arterial wall thickening; however, the results suggest a significant association of IL‑6 serum levels with CCA IMT only in the RRMS group.

Association of cervical atherosclerosis on Doppler ultrasonography and postoperative delirium in patients undergoing spinal surgery: a single-center, retrospective, observational study

PURPOSE

This study aimed to evaluate the association between cervical atherosclerosis on Doppler ultrasonography and postoperative delirium (POD) in patients undergoing spinal surgery.

METHODS

In this retrospective observational study using prospectively collected data, 295 consecutive patients aged > 50 years underwent spine surgery at a single institution between March 2015 and February 2021. Cervical atherosclerosis was defined as the intima-media thickness (IMT) of the common carotid artery (CCA) being ≥ 1.1 mm on pulsed-wave Doppler ultrasonography. Univariate and multivariate logistic regression analyses were performed with the prevalence of postoperative delirium as a dependent variable. Age, sex, body mass index, medical history, American Society of Anesthesiologists Physical Status (ASA-PS), CHADS2 score (an assessment score for stroke), instrumentation, duration of surgery, blood loss, and cervical arteriosclerosis were the independent variables.

RESULTS

Twenty-seven patients of 295 (9.2%) developed delirium postoperatively. Forty-one (13.9%) of the 295 patients had cervical atherosclerosis. Their univariate analyses showed that age (P = 0.001), hypertension (P = 0.016), cancer (P = 0.046), antiplatelet agent use (P < 0.001), ASA-PS ≥ 3 (P < 0.001), CHADS2 score (P < 0.001), cervical atherosclerosis (P = 0.008), and right CCA-IMT (P = 0.007) were significantly associated with POD. However, multivariate logistic regression analyses showed older age (odds ratio [OR], 1.109; 95% confidence interval [CI] 1.035-1.188; P = 0.03) and antiplatelet agent use (OR, 3.472; 95% CI 1.221-9.870; P = 0.020) to be significantly associated with POD.

CONCLUSIONS

There was a significant association between POD and the prevalence of cervical atherosclerosis using the univariate logistic regression analysis. Furthermore, multivariate logistic regression analyses showed that older age and antiplatelet agent use were independently associated with POD.

Stroke and its correlates among patients on maintenance hemodialysis in Cameroon

BACKGROUND

End-stage kidney disease is an independent risk factor for stroke; however, the relationship between hemodialysis and stroke in Sub-Saharan Africa has not been established.

OBJECTIVE

To evaluate the incidence, associated factors, and clinical outcome of stroke among patients undergoing maintenance hemodialysis in Cameroon.

METHODS

A hospital-based retrospective study using data from the medical files of 1060 patients on maintenance hemodialysis (given twice a week) was conducted. Patients with stroke prior to starting hemodialysis were excluded. Socio-demographic data, comorbidities, dialysis parameters, and data concerning the diagnosis of stroke were retrieved and analyzed.

RESULTS

The dialysis vintage (duration of time on dialysis) averaged 11.4 ± 9.2 months. The incidence of stroke was 6.1 events per 1000 patient-years, with hemorrhagic stroke being most common (66%). Eighty percent of strokes occurred before the 30th month of dialysis. Sixty percent of strokes occurred within 24 h of a dialysis session. Predictive factors for stroke were diabetes mellitus (p = 0.026), heart failure (p = 0.045), poor dialysis compliance (p = 0.001), and short vintage (p = 0.001). The overall mortality rate was 52% and was higher for hemorrhagic stroke (60%). The leading causes of death were multiple organ failure and sepsis.

CONCLUSION

The incidence of stroke is high among hemodialysis patients in Cameroon and hemorrhagic stroke is the commonest type. Diabetes and heart failure triple the risk of stroke. Mortality in patients who suffered a stroke was high.

Renal Resistive Index: Revisited

Introduction Chronic kidney disease (CKD) is universally considered a public health burden and the majority of cases are found to be diabetic at the time of diagnosis. Renal biopsy is the prime modality for the complete evaluation of renal injuries but is invasive. Duplex Doppler sonography can help to determine renal resistive index (RRI), which is an excellent marker for demonstrating dynamic or structural changes of intrarenal vessels. In this study, we evaluated the intrarenal hemodynamic abnormalities with RRI in diabetic and non-diabetic kidney disease patients. Also, RRI was correlated with the established parameters of renal dysfunction, i.e., estimated glomerular filtration rate (eGFR) and other biochemical parameters. Results There was a significant correlation of RRI with eGFR and serum creatinine indicating its role as a Doppler parameter, which can be used as complementary to biochemical parameters. A remarkable difference was noted in the RRI values between diabetic and non-diabetic groups in the early stages of CKD, revealing its ability to arrive at etiopathogenesis in the early stages. The renal resistive index increases in a sequential pattern and is an indicator of declining renal function. Conclusions The addition of sonographic parameters like renal resistive index could help in the complete evaluation of chronic kidney disease in diabetic and non-diabetic groups. A sequential increase in renal resistive index is a better indicator of the progressive worsening of renal function as opposed to an absolute cut-off value.

Association between the triglyceride–glucose index and chronic kidney disease in adults

BACKGROUND

Chronic kidney disease (CKD) is characterized as a progressive dysfunction of the kidney, and it might have a close relationship with insulin resistance. We utilized the triglyceride-glucose (TyG) index, a reliable marker of insulin resistance, to evaluate the association between the TyG index and CKD in adults from the general population.

METHODS

This was a cross-sectional study obtaining data from the 2015-2018 National Health and Nutrition Examination Survey. The estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) served as kidney function indicators. We defined CKD as the existence of either low eGFR (eGFR < 60 mL/min/1.73 m² BSA) or albuminuria (UACR > 30 mg/g). Multivariate regressions, correlated subgroup analyses, and interaction terms were performed in this study.

RESULTS

For 4361 recruited participants, the mean TyG index was 8.60 ± 0.68, and the prevalence of CKD was 13.35%. Participants with a higher TyG index showed a higher UACR level (β = 25.10, 95% CI: 6.76, 43.44, P = 0.0074) and higher levels of CKD (OR = 1.34, 95% CI: 1.13, 1.59, P = 0.0006). The positive relationship between the TyG index and CKD became stronger and remained significant in the overweight (OR = 1.61, 95% CI: 1.18, 2.20, P = 0.0027) and obese (OR = 2.48, 95% CI: 1.95, 3.15, P < 0.0001) groups and in people with diabetes (OR = 1.94, 95% CI: 1.46, 2.56, P < 0.0001).

CONCLUSIONS

Higher TyG index was strongly associated with a higher UACR level and higher values of albuminuria and CKD, which might be useful in kidney function screening especially among people in disadvantageous socioeconomic conditions with no availability for direct measurement of kidney function. However, more well-designed studies are still needed to validate this relationship.

[Experience in using teriparatide for the treatment of postoperative hypoparathyroidism in hemodialysis patients]

The frequency of chronic postoperative hypoparathyroidism after total parathyroidectomy for secondary and tertiary hyperparathyroidism in patients with end-stage renal failure, according to various authors, can reach 20% or more. Prescribing active metabolites of vitamin D and calcium it is not always sufficient for achievement of target goals. This dictates the need for replacement therapy with recombinant parathyroid hormone. Teriparatide is the only drug of this series approved by the American Food and Drug Administration (FDA) and registered in the Russian Federation. However, it is registered as an anabolic anti-osteoporotic drug and is not indicated for the treatment of chronic hypoparathyroidism. The use of teriparatide in postoperative hypoparathyroidism in patients receiving renal replacement therapy with programmed hemodialysis in the Russian Federation has not been previously studied. Data on this issue is also limited in foreign literature. However, it is a potential treatment option for hemodialysis patients with chronic hypoparathyroidism and severe bone disorders. In this article, we present 2 clinical cases of substitution and anabolic therapy with teriparatide in this cohort of patients.

Association of renal impairment with cognitive dysfunction in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA)

Introduction

Chronic kidney disease (CKD) is a recognized risk factor for cognitive impairment. Identification of those at greatest risk of cognitive impairment may facilitate earlier therapeutic intervention. This study evaluated associations between estimated glomerular filtration rate (eGFR) and cognitive function in the Northern Ireland Cohort for the Longitudinal Study of Ageing.

Methods

Data were available for 3412 participants ≥50 years of age living in non-institutionalized settings who attended a health assessment between February 2014 and March 2016. Measures of serum creatinine (SCr) and cystatin C (cys-C) were used for eGFR. Cognitive function was measured using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE).

Results

Following adjustment for potential confounders, a single unit decrease in eGFR was significantly associated with reduced cognitive function defined by an MMSE ≤24/30 {eGFR calculated using serum cys-C [eGFRcys]: β = −0.01 [95% confidence interval (CI) −0.001 to −0.01], P = 0.01} and MoCA <26/30 [β = −0.01 (95% CI −0.002 to −0.02), P = 0.02]. Similarly, CKD Stages 3–5 were also associated with a moderate increase in the odds of cognitive impairment (MMSE ≤24) following adjustment for confounders [eGFRcys: odds ratio 2.73 (95% CI 1.38–5.42), P = 0.004].

Conclusions

Decreased eGFRcys was associated with a significantly increased risk of cognitive impairment in a population-based cohort of older adults. However, there was no evidence of an association between cognitive impairment and the more commonly used eGFR calculated using SCr. eGFRcys may offer improved sensitivity over eGFRcr in the determination of renal function and associated risk of cognitive impairment.

Chronic kidney disease, atherosclerotic plaque characteristics on carotid magnetic resonance imaging, and cardiovascular outcomes

Background

It is unclear whether faster progression of atherosclerosis explains the higher risk of cardiovascular events in CKD. The objectives of this study were to 1. Characterize the associations of CKD with presence and morphology of atherosclerotic plaques on carotid magnetic resonance imaging (MRI) and 2. Examine the associations of baseline CKD and carotid atherosclerotic plaques with subsequent cardiovascular events.

Methods

In a subgroup (N = 465) of Systolic Blood Pressure Intervention Trial.

(SPRINT) participants, we measured carotid plaque presence and morphology at baseline and after 30-months with MRI. We examined the associations of CKD (baseline eGFR < 60 ml/min/1.73m²) with progression of carotid plaques and the SPRINT cardiovascular endpoint.

Results

One hundred and ninety six (42%) participants had CKD. Baseline eGFR in the non-CKD and CKD subgroups were 77 ± 14 and 49 ± 8 ml/min/1.73 m², respectively. Lipid rich necrotic-core plaque was present in 137 (29.5%) participants. In 323 participants with both baseline and follow-up MRI measurements of maximum wall thickness, CKD was not associated with progression of maximum wall thickness (OR 0.62, 95% CI 0.36 to 1.07, p = 0.082). In 96 participants with necrotic core plaque at baseline and with a valid follow-up MRI, CKD was associated with lower odds of progression of necrotic core plaque (OR 0.41, 95% CI 0.17 to 0.95, p = 0.039). There were 28 cardiovascular events over 1764 person-years of follow-up. In separate Cox models, necrotic core plaque (HR 2.59, 95% CI 1.15 to 5.85) but not plaque defined by maximum wall thickness or presence of a plaque component (HR 1.79, 95% CI 0.73 to 4.43) was associated with cardiovascular events. Independent of necrotic core plaque, CKD (HR 3.35, 95% CI 1.40 to 7.99) was associated with cardiovascular events.

Conclusions

Presence of necrotic core in carotid plaque rather than the presence of plaque per se was associated with increased risk of cardiovascular events. We did not find CKD to be associated with faster progression of necrotic core plaques, although both were independently associated with cardiovascular events. Thus, CKD may contribute to cardiovascular disease principally via mechanisms other than atherosclerosis such as arterial media calcification or stiffening.

Trial Registration

NCT01475747, registered on November 21, 2011.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02260-x.

M2 Monocyte Polarization in Dialyzed Patients Is Associated with Increased Levels of M-CSF and Myeloperoxidase-Associated Oxidative Stress: Preliminary Results

Cardiovascular diseases represent a major issue in terms of morbidity and mortality for dialysis patients. This morbidity is due to the accelerated atherosclerosis observed in these patients. Atherosclerosis is a chronic inflammatory disease characterized by key players such as monocytes, macrophages, or oxidized LDLs. Monocytes-macrophages are classified into subsets of polarized cells, with M1 and M2 macrophages considered, respectively, as pro- and anti-inflammatory. (1) Methods: The monocyte subsets and phenotypes were analyzed by flow cytometry. These data were completed by the quantification of plasma M-CSF, IL-8, CRP, Mox-LDLs, Apo-B, Apo-AI, chloro-tyrosine, and homocitrulline concentrations. The statistical differences and associations between two continuous variables were assessed using the Mann-Whitney U test and Spearman's correlation coefficient, respectively. (2) Results: Hemodialyzed patients showed a significant increase in their concentrations of CRP, M-CSF, and IL-8 (inflammation biomarkers), as well as chloro-tyrosine and homocitrulline (myeloperoxidase-associated oxidative stress biomarkers). Moreover, we observed a higher percentage of M2 monocytes in the plasma of hemodialysis patients as compared to the controls. (3) Conclusions: Our data suggest that oxidative stress and an inflammatory environment, which is amplified in hemodialysis patients, seems to favor an increase in the concentration of circulating M-CSF, therefore leading to an increase in M2 polarization among circulating monocytes.

Sodium thiosulphate and progression of vascular calcification in end-stage renal disease patients: a double-blind, randomized, placebo-controlled study

BACKGROUND

Sodium thiosulphate (NaTS) is mostly used in haemodialysis (HD) patients with calcific uraemic arteriolopathy. This double-blind, randomized, placebo-controlled study assessed the effect of NaTS on progression of cardiovascular calcifications in HD patients.

METHODS

From 65 screened patients, we recruited 60 patients with an abdominal aorta Agatston calcification score ≥100. Thirty patients were randomized to receive NaTS 25 g/1.73 m2 and 30 patients to receive 100 mL of 0.9% sodium chloride intravenously during the last 15 min of HD over a period of 6 months. The primary endpoint was the absolute change of the abdominal aortic calcification score.

RESULTS

The abdominal aortic calcification score and calcification volume of the abdominal aorta increased similarly in both treatment groups during the trial. As compared with the saline group, patients receiving NaTS exhibited a reduction of their iliac artery calcification score (-137 ± 641 versus 245  ± 755; P = 0.049), reduced pulse wave velocity (9.6  ± 2.7 versus 11.4 ± 3.6; P = 0.000) and a lower carotid intima-media thickness (0.77  ± 0.1 versus 0.83  ±  00.17; P = 0.033) and had better preservation of echocardiographic parameters of left ventricular hypertrophy. No patient of the NaTS group developed new cardiac valve calcifications during the trial as compared with 8 of 29 patients in the saline group. By univariate analysis, NaTS therapy was the only predictor of not developing new valvular calcifications. No adverse events possibly related to NaTS infusion were noted.

CONCLUSIONS

While NaTS failed to retard abdominal aortic calcification progress, it positively affected calcification progress in iliac arteries and heart valves as well as several other cardiovascular functional parameters.

A systematic review and external validation of stroke prediction models demonstrates poor performance in dialysis patients

OBJECTIVES

The objective of this study was to systematically review and externally assess the predictive performance of models for ischemic stroke in incident dialysis patients.

STUDY DESIGN AND SETTING

Two reviewers systematically searched and selected ischemic stroke models. Risk of bias was assessed with the PROBAST. Predictive performance was evaluated within The Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), a large prospective multicenter cohort of incident dialysis patients. For discrimination, c-statistics were calculated; calibration was assessed by plotting predicted and observed probabilities for stroke, and calibration-in-the-large.

RESULTS

Seventy-seven prediction models for stroke were identified, of which 15 were validated. Risk of bias was high, with all of these models scoring high risk in one or more domains. In NECOSAD, of the 1,955 patients, 127 (6.5%) suffered an ischemic stroke during the follow-up of 2.5 years. Compared with the original studies, most models performed worse with all models showing poor calibration and discriminative abilities (c-statistics ranging from 0.49 to 0.66). The Framingham showed reasonable calibration; however, with a c-statistic of 0.57 (95% CI 0.50-0.63), the discrimination was poor.

CONCLUSION

This external validation demonstrates the weak predictive performance of ischemic stroke models in incident dialysis patients. Instead of using these models in this fragile population, either existing models should be updated, or novel models should be developed and validated.

Increased Endothelin-1 Mrna Expression in Peripheral Blood Monocytes of Dialysis Patients

Objective

To compare plasma endothelin (ET)-1 level and ET-1 mRNA level in peripheral blood monocytes of patients undergoing hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD).

Design

Endothelin-1 mRNA level in peripheral blood monocytes and plasma ET -1 level were studied in 30 HD patients, 15 CAPD patients, 20 chronic renal failure patients not being dialyzed, and 20 normal healthy controls. Hemodialysis patients were dialyzed three times per week with a bicarbonate dialysate. Different types of dialyzer membrane, viz., cellulose triacetate, cuprophane, poly-sulfone, polyacrylonitrile, and ethylenevinylalcohol were used in 8,6,6,5, and 5 patients, respectively. Continuous ambulatory peritoneal dialysis patients were dialyzed with four daily exchanges of a 2-L dialysate containing glucose at a concentration of 1.5% to 2.5%.

Results

Higher levels of ET -1 mRNA in monocytes were observed in HD patients than in CAPD patients (p < 0.01), chronic renal failure patients (p < 0.01), or normal healthy controls (p < 0.001). The level of ET -1 mRNA in monocytes at the end of HD was not significantly higher than that at the start of HD. ln addition, these mRNA levels in HD patients showed littledifference with different types of dialysis membrane. Plasma ET -1 level in HD patients (10.2 ± 2.4 pg/mL) was also higher than that in CAPD patients (7.8 ± 1.6 pg/mL, p < 0.01), in chronic renal failure patients (4.8 ± 1.2 pg/mL, p < 0.01), or in normal controls (2.6 ± 0.8 pg/mL, p < 0.001).

Conclusion

Dialysis itself did not significantly affect ET -1 mRNA levels in monocytes. Chronic stimulation of peripheral blood monocytes may be associated with higher levels of ET -1 mRNA and plasma ET -1 in HD patients than in CAPD patients.

Carotid Intima-Media Thickness: A Surrogate Marker for Cardiovascular Disease in Chronic Kidney Disease Patients

Background:

Cardiovascular disease (CVD) is the leading cause of mortality in patients with chronic kidney disease (CKD). Carotid intima-media thickness (CIMT) is a measure of atherosclerotic vascular disease and considered a comprehensive picture of all alterations caused by multiple cardiovascular risk factors over time on the arterial walls. We therefore sought to determine the CIMT of the common carotid artery in patients with CKD and to evaluate the clinical pattern and prevalence of CVD in CKD patients.

Methods:

A case-control study involving 100 subjects made of 50 patients with CKD stages 2 to 4 and 50 age and sex matched apparently normal individuals. Carotid intima-media thickness of the common carotid artery was considered thickened if it measured greater than 0.8 mm. All subjects had laboratory investigations, 12-lead electrocardiogram, transthoracic echocardiography, and ankle-brachial index.

Results:

The mean CIMT was higher in CKD population compared with controls (P < .001). Eighty-four percent of the study population was found to have thickened CIMT compared with 18% of controls (P < .001). Patients with CKD had significantly higher blood pressure and heart rate than controls. Cardiovascular disease was also more prevalent among patients with CKD as compared with controls. Carotid intima-media thickness positively correlated with age, blood pressure, and random blood sugar.

Conclusions:

As CIMT was well correlated with many cardiovascular risk factors among CKD patients, it may serve as a surrogate marker for CVD and its early assessment may target patients who may need more aggressive therapy to retard the progression of kidney disease and improve outcome.

Malnutrition, inflamation and atherosclerosis (MIA syndrome) in patients with end stage renal disease on maintenance hemodialysis (a single centre experience)

BACKGROUND

Inflammation and malnutrition play an important role in endothelial dysfunction, atherosclerosis and excessive cardiovascular morbidity and mortality in ESRD patients AIM OF THE STUDY: The primary objective is to determine the prevalence of inflammation, malnutrition and atherosclerosis in patients on maintenance haemodialysis. Secondary objective was to determine the association for atherosclerosis with inflammation and malnutrition.

PATIENT AND METHODS

One hundred and one adult patients with end stage renal disease on maintenance haemodialysis who are met with the exclusion criteria were enrolled in this cross sectional study from haemodialysis unit of Baghdad teaching hospital over the period of July/2015 - June 2016. All patients were thoroughly examined and many variables were evaluated (age, gender, blood pressure, diabetes mellitus, serum lipid profile, smoking habits, serum albumin, CRP, calcium, Phosphate, Parathyroid hormone and haemoglobin measurements). All patients underwent a carotid Doppler ultrasound study.

RESULTS

Atherosclerosis was present in 65.3%: 58.4% of patients had malnutrition and 43.6% had inflammation. The association for atherosclerosis and high CRP and low serum albumin is strong and independent of other atherosclerosis risk factors. There is significant inverse and independent correlation between CRP and albumin.

CONCLUSION

Inflammation (high serum CRP) and malnutrition (low serum albumin) in patients on haemodialysis are significantly associated with carotid atherosclerosis. Inflammation was more prevalent in the malnourished patients than in those with normal nutritional status.

Arteriosclerosis in Dialysis Patients

Arteriosclerosis is a constant problem in long-term hemodialysis patients. Computer tomography of the abdominal aorta allows a well-defined and reproducible evaluation of aortosclerosis. In the cross-sectional study, aortosclerosis was significantly accelerated in 84 chronic hemodialysis patients and was comparable to the results found in 20-year older control patients without renal disease. The increase of aortosclerosis correlated significantly with age of the patient, smoking, and duration of dialysis therapy. Furthermore, increased VLDL cholesterol and decreased HDL cholesterol seem to enhance aortosclerosis in our dialysis patients. In the longitudinal study (two CT scans with a time interval of 87 ± 62.7 months) in 36 dialysis patients, progressed aortosclerosis correlated significantly with the long duration of hypertriglyceridemia, VLDL cholesterol, uric acid, and calcium phosphate products. Progression of aortosclerosis was reduced in parathyroidectomized patients. The study suggests that premature aortosclerosis is found in dialysis patients. In addition to the common risk factor of aortosclerosis, disturbed calcium phosphate and parathyroid hormone metabolism seem to enhance aortosclerosis in patients under maintenance hemodialysis.

Mineral metabolism and cardiovascular disease in CKD

The mineral bone disorder of CKD, called Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD), has a major role in the etiology and progression of cardiovascular disease in CKD patients. Since the main emphasis in CKD-MBD is on three categories (bone abnormalities, laboratory abnormalities, and vascular calcifications), we have routinely accepted ectopic cardiovascular calcifications as a central risk factor in the pathophysiology of CKD-MBD for cardiac events. However, recent compelling evidence suggests that some CKD-MBD-specific factors other than vascular calcification might contribute to the onset of cardiovascular disease. Most notable is fibroblast growth factor-23 (FGF23), which is thought to be independently associated with cardiac remodeling. Slow progression of cardiac disorders, such as vascular calcification and cardiac remodeling, characterizes cardiac disease due to CKD-MBD. In contrast, fatal arrhythmia may be induced when QT prolongation occurs with CKD-MBD treatment, such as with lower Ca dialysate or the use of calcimimetics. Sudden onset of fatal cardiac events, such as heart failure and sudden cardiac death, due to fatal arrhythmia would be another distinctive phenomenon of CKD-MBD. This may be defined as CKD-MBD-specific cardiac complex syndrome.

Intima-media thickness: indicator of cardiovascular risk and measure of the extent of atherosclerosis

The measurement of intima-media thickness (IMT) of large superficial arteries, especially the carotid, using high-resolution B-mode ultrasonography has emerged as one of the methods of choice for determining the anatomic extent of atherosclerosis and for assessing cardiovascular risk. IMT measurement obtained by ultrasonography correlates very well with pathohistologic measurements and the reproducibility of this technique is good. Population studies have shown a strong correlation between carotid IMT and several cardiovascular risk factors, and it has also been found to be associated with the extent of atherosclerosis and end-organ damage of high-risk patients. Therefore, increased carotid IMT is a measure of athero-sclerotic burden and a predictor of subsequent events. Because of its quantitative value, carotid IMT measurement is more and more frequently used in clinical trials to test the effects of different preventive measures, including drugs. More recently, there has been interest in the clinical use of this technique for detecting preclinical (asymptomatic) atherosclerosis and for identifying subjects at high risk. Measurement of carotid IMT could influence a clinician to intervene with medication and to use more aggressive treatment of risk factors in primary prevention, and in patients with atherosclerotic disease in whom there is evidence of progression and extension of atherosclerotic disease. For more extensive use of this method in clinical practice a consensus concerning the standardization of methods of measurement and precise definition of threshold between normal and pathologic IMT value is urgently needed.

Does a Reduction in the Glomerular Filtration Rate Increase the Overall Severity of Coronary Artery Stenosis?

OBJECTIVE

Chronic kidney disease is a risk factor of coronary events, however, its impact on coronary artery stenosis has not yet been clarified with the use of a large database. We examined the association between a reduced glomerular filtration rate (GFR) and the overall severity of coronary stenosis.

METHODS

We enrolled 1,150 patients [mean age, 68±12 (SD) years; 66.6% men] who consecutively underwent coronary angiography for suspected stable angina pectoris. The overall severity of stenosis in the coronary arteries was assessed by the Gensini score (GS), and its logarithmic values (log-GS) were used for statistical analyses since the GS does not follow a normal distribution.

RESULTS

The log-GS was significantly larger in men than in women (2.5±1.5 vs. 1.9±1.7), while the estimated GFR (eGFR) and comorbidities were comparable between both sexes. A multivariate regression analysis indicated that age, smoking, eGFR, HDL-cholesterol and HbA1c were independent explanatory variables of the log-GS in men, although the eGFR explained only 1.2% of the log-GS variation. In women, the eGFR was not included in the significant explanatory variables shown by the multivariate analysis. However, the sex difference in the regression for the eGFR-log-GS relationship was not statistically significant.

CONCLUSION

A reduced eGFR is a significant, but minor, determinant of the overall severity of coronary artery stenosis in men and potentially women.

Ischemic Heart Disease in Patients with End-Stage Kidney Disease

BACKGROUND

It was recently reported that the severity of coronary and carotid atherosclerosis in patients with end-stage kidney disease (ESKD) has improved over the last two decades. However, the frequency of coronary artery events observed at the initiation of dialysis remains high.

SUMMARY

Recently, 5 different clinical types of acute myocardial infarction (MI) were introduced in the third universal definition of MI. Type 2 MI, known as secondary MI, is a more heterogeneous entity, where a condition other than coronary artery narrowing contributes to an acute imbalance in oxygen supply and demand. In patients with chronic kidney disease, it has been demonstrated that type 2 MI is more common than type 1 MI, which is associated with coronary occlusive disease. It is suspected that patients with ESKD also often have type 2 MI. Factors associated with incremental increases in oxygen demand may cause myocardial ischemia in ESKD.

KEY MESSAGES

Significant epicardial coronary narrowing might not be a necessary precursor of myocardial ischemia in ESKD. To prevent ischemic heart disease and improve prognosis in patients with ESKD, we need to pay attention not only to coronary stenotic lesions, but also to the factors associated with the induction of an imbalance in myocardial oxygen supply and demand.

Correlation between small dense low-density lipoprotein cholesterol and carotid artery intima-media thickness in a healthy Chinese population

BACKGROUND

Small dense low-density lipoprotein cholesterol (sdLDL-C) concentration was useful in the assessment of the presence of cardiovascular diseases (CVD) and its severity. We examined whether SdLDL-C is more closely associated with carotid artery intima-media thickness (CA-IMT), a surrogate measure of atherosclerosis, than LDL-C and traditional CVD risk factors in Chinese healthy subjects.

METHODS

We measured CA-IMT, blood pressure (BP), sdLDL-C, glucose metabolism and lipid in 183 native Chinese healthy subjects. CA-IMT was assessed by ultrasonography, and sdLDL-C concentrations were measured by a homogenous assay. Pearson's correlation coefficient analyses and Multiple regression analyses were used to examine the relationships between CA-IMT values and other clinical variables.

RESULTS

The sdLDL-C level was significantly higher in males than in females (p <0.05) and there was an age effect on sdLDL-C (p <0.05). When the effects of age, gender and other traditional CVD risk factors were adjusted using multiple regression analysis. CA-IMT remained significantly associated with sdLDL-C(β = 0.437, p <0.001).

CONCLUSIONS

There are gender and age differences in sdLDL-C levels among a healthy Chinese population. Moreover, we found adjusted traditional CVD risk factors such as higher age, male sex, and other traditional CVD risk factors, the association between CA-IMT and SdLDL-C remained significant. sdLDL-C is may be a useful predictor in the assessment of CA-IMT in Chinese population.

Menopausal symptoms in women with chronic kidney disease

OBJECTIVE

This study aims to determine whether menopausal symptoms differed between women with chronic kidney disease (CKD) and women without CKD, and whether CKD modified associations of late vasomotor symptoms (VMS) with mortality and/or cardiovascular events.

METHODS

CKD, defined as estimated glomerular filtration rate lower than 60 mL/minute/1.73 m (using the Chronic Kidney Disease Epidemiology Collaboration equation), was determined in 17,891 postmenopausal women, aged 50 to 79 years at baseline, in the multiethnic Women's Health Initiative cohort. Primary outcomes were presence, severity, and timing/duration of VMS (self-reported hot flashes and night sweats) at baseline. We used polytomous logistic regression to test for associations among CKD and four VMS categories (no VMS; early VMS-present before menopause but not at study baseline; late VMS-present only at study baseline; persistent VMS-present before menopause and study baseline) and Cox regression to determine whether CKD modified associations between late VMS and mortality or cardiovascular events.

RESULTS

Women with CKD (1,017 of 17,891; mean estimated glomerular filtration rate, 50.7 mL/min/1.73 m) were more likely to have had menopause before age 45 years (26% vs 23%, P = 0.02) but were less likely to experience VMS (38% vs 46%, P < 0.001) than women without CKD. Women with CKD were not more likely than women without CKD to experience late VMS. Late VMS (hazard ratio, 1.16; 95% CI, 1.04-1.29) and CKD (hazard ratio, 1.74; 95% CI, 1.54-1.97) were each independently associated with increased risk for mortality, but CKD did not modify the association of late VMS with mortality (Pinteraction = 0.53), coronary heart disease (Pinteraction = 0.12), or stroke (Pinteraction = 0.68).

CONCLUSIONS

Women with mild CKD experience earlier menopause and fewer VMS than women without CKD.

Impact of Carotid Intima-Media Thickness on Long-term Outcome in Hemodialysis Patients

Background:

Chronic kidney disease (CKD) patients on hemodialysis are highly prone to cardiovascular disease, which accounts for roughly half of the mortality in these patients. Atherosclerosis begins many years before the development of clinical manifestations. Measurement of carotid intima-media thickness (CIMT) is a noninvasive procedure to detect early atherosclerotic changes.

Aims:

The aim of the study was to evaluate the correlation between CIMT and cardiovascular risk factors and to investigate its prognostic significance in CKD patients on hemodialysis.

Materials and Methods:

This was a prospective study carried out over a period of 18 months. Total 88 patients on hemodialysis and 50 healthy controls were enrolled in the study. Biochemical assay and CIMT was assessed using the high resolution 7.5 MHz sonography technique in all subjects.

Results:

Significant positive correlation was found with age, blood urea, serum creatinine, serum triglyceride, low-density lipoprotein, serum phosphorus, serum calcium-phosphorus product, serum uric acid, 24 h urine protein, systolic blood pressure, diastolic blood pressure, and body mass index. Negative correlation was found with estimated glomerular filtration rate. Adjusted hazards ratios of all cause and cardiovascular mortality for an increase of 0.1 mm in CIMT was 1.16 (95% confidence interval 0.15-9.09). Patients with CIMT value <0.97 mm had a renal survival rate of 73.4% while patients with value >0.97 mm had a renal survival rate of 16.5%.

Conclusion:

Uremia is an additive risk factors in those subjects who have raised CIMT despite of traditional cardiovascular risk factors.

Reduced Stroke Risk After Parathyroidectomy in End-Stage Renal Disease: A 13-Year Population-Based Cohort Study

Research information on the risk of stroke in patients with dialysis-dependent end-stage renal disease (ESRD) who have undergone parathyroidectomy (PTX) is scant. We used a nationwide health insurance claims database to select all patients with dialysis-dependent ESRD age 18 years and older for the study population. Of the patients with ESRD, we selected 1083 patients who had undergone PTX between 1998 and 2006 as the PTX group and frequency-matched 1083 patients with ESRD by sex, age, years since the disease diagnosis, and the year of undergoing PTX as the non-PTX group. We used a multivariate Cox proportional hazards regression analysis to measure the risk of stroke for the PTX group compared with the non-PTX group after adjusting for sex, age, premium-based income, urbanization, and comorbidity. The mean follow-up periods were 6.08 and 5.38 years for the PTX and non-PTX groups, respectively. After adjusting for previously mentioned variables, significant risk reductions of stroke (adjusted hazard ratio = 0.57, 95% confidence interval = 0.41-0.79), particularly those of hemorrhagic stroke (adjusted hazard ratio = 0.34, 95% confidence interval = 0.20-0.57), with PTX were observed. Chronologically, the risk of stroke in the PTX group decreased in the second year after PTX and persisted for >3 years. PTX reduces the risk of stroke, particularly that of hemorrhagic stroke, in patients with dialysis-dependent ESRD. Other factors for risk reduction include sex (females), an age <65 years, and the presence of comorbidity.

Ischemic stroke: the impact of renal dysfunction on 1-year mortality

BACKGROUND

Atherosclerosis is accelerated in patients with different stages of chronic renal failure. Renal dysfunction predicts mortality in patients with myocardial infarction and congestive heart failure. Less is known about the impact of renal dysfunction on mortality after ischemic stroke. The aim of the study was to investigate the impact of renal dysfunction on 1-year mortality.

PATIENTS AND METHODS

All 390 patients (207 men and 183 women) suffered from ischemic stroke in 1-year period were included in our study. Telephonic follow-up after 1 year was performed. The mean age of our patients was 71.0 ± 11.6 years, ranged from 36 to 96 years. Glomerular filtration rate (GFR) was calculated according to abbreviated Modification of Diet in Renal Disease formula. At admission and at discharge National Institutes of Health Stroke Scale (NIHSS) were performed.

RESULTS

The mean GFR in our patients was 66.0 ± 20.68 ml/min/1.73 m(2). There were 123 (31.5 %) deaths in 1-year period. Patients who died were older (P < 0.001), had higher NIHSS at admission and at discharge (both P < 0.001), higher high-sensitive C-reactive protein (P = 0.002), lower albumin (P < 0.001), lower GFR (P = 0.044), had more frequent atrial fibrillation (P < 0.001), and were less frequent actual smokers (P = 0.003). No differences in presence of diabetes and hypertension, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides between patients who died or survived were found. With Cox multivariable regression analysis age (P = 0.037), gender (P = 0.005), NIHSS at admission (P = 0.005) and discharge (P < 0.001), albumin (P = 0.005) and also GFR (P = 0.025) were predictors of 1-year mortality.

CONCLUSIONS

In patients with ischemic stroke, renal dysfunction (decreased GFR) was associated with 1-year mortality. GFR was independent predictor of mortality.

Evidence for the prevention and treatment of stroke in dialysis patients

The risks of both ischemic and hemorrhagic stroke are particularly high in dialysis patients of any age and outcomes are poor. It is therefore important to identify strategies that safely minimize stroke risk in this population. Observational studies have been unable to clarify the relative importance of traditional stroke risk factors such as blood pressure and cholesterol in those on dialysis, and are affected by biases that usually make them an inappropriate source of data on which to base therapeutic decisions. Well-conducted randomized trials are not susceptible to such biases and can reliably investigate the causal nature of the association between a potential risk factor and the outcome of interest. However, dialysis patients have been under-represented in the cardiovascular trials which have proven net benefit of commonly used preventative treatments (e.g., antihypertensive treatments, low-dose aspirin, carotid revascularization, and thromboprophylaxis for atrial fibrillation), and there remains uncertainty about safety and efficacy of many of these treatments in this high-risk population. Moreover, the efficacy of renal-specific therapies that might reduce cardiovascular risk, such as modulators of mineral and bone disorder, online hemodiafiltration, and daily (nocturnal) hemodialysis, have not been tested in adequately powered trials. Recent trials have also demonstrated how widespread current practices could be causing stroke. Therefore, it is important that reliable information on the prevention and treatment of stroke (and other cardiovascular disease) in dialysis patients is generated by performing large-scale randomized trials of many current and future treatments.

Association between circulating endothelial cells and carotid atherosclerosis in patients receiving maintenance hemodialysis

Accelerated atherosclerosis is the major cause of mortality in maintenance hemodialysis (MHD) patients, and endothelial injury associated with MHD might contribute strongly to pathogenesis. The current study was designed to explore possible associations between circulating endothelial cells (CECs) and intima-media thickness of common carotid artery (CCA-IMT) as an indicator of carotid atherosclerosis. Sixty-two MHD patients and 26 age- and sex-matched healthy volunteers were recruited. The number of CECs was determined in peripheral blood using multiparametric flow cytometry. CCA-IMT and presence of plaques in the common carotid arteries were assessed with ultrasound. Laboratory tests results and the demographics were recorded. The finding indicated that numbers of CECs were higher in patients before hemodialysis (predialysis) compared with numbers in controls (P = 0.045). CCA-IMT was also significantly higher in patients than in controls (P < 0.01). A positive relationship was observed between predialysis CECs numbers and CCA-IMT (P < 0.01) in MHD patients. In multiple linear regression analysis, the relationship between the predialysis CECs level and CCA-IMT remained the same even if adjusting for confounding effects. Accordingly, the investigation indicates that the CECs level is positively associated with CCA-IMT in our hemodialysis patients. CECs might be an important marker to the severity of carotid atherosclerosis in MHD patients.

Stroke and renal dysfunction

Stroke is the most frequent neurological disease and represents a continuously evolving medical and social problem. Chronic kidney disease (CKD) is also an important worldwide public health problem. Renal dysfunction carries a substantial risk of cardiovascular morbidity and mortality and an independent, graded association between renal function and cardiovascular events was found. In the last 15years the link between CKD and cerebrovascular disease has become more apparent. Patients with end stage renal disease treated with maintenance hemodialysis have a much higher incidence of stroke than the general population and stroke is one of the major causes of death in these patients. Nowadays ischemic subtype of stroke is present in approximately 70% of dialysis patients. In population based studies conflicting results have been reported about the association between stroke and CKD before replacement therapy. However, in high risk patients, defined by the presence of either cardiovascular disease or cardiovascular risk factors, different stages of CKD are clearly associated with subsequent stroke. In patients with stroke the exact prevalence of renal dysfunction is not known. Reported prevalence from a few published studies is up to 38% and it is higher than that in age-matched control groups. Furthermore, in patients suffering from stroke renal dysfunction is associated with short and long term mortality. The most effective treatment of stroke in patients with CKD is not known and further studies are needed.

Features of atherosclerosis in hemodialysis patients

Background

Cardiovascular disease is the main cause of mortality in dialysis patients. Carotid intima–media thickness (CIMT) is used as a surrogate marker of early atherosclerosis. Atherosclerosis can cause vascular access failure. The purpose of this study was to define the clinical features of atherosclerosis in hemodialysis patients based on CIMT and to define the relationship between CIMT and access failure.

Methods

In this cross-sectional study, the CIMT of 60 patients on hemodialysis was examined using B-mode Doppler ultrasonography between May 2012 and November 2012. Carotid atherosclerosis was defined as a CIMT≥0.9 mm or the incidence of atherosclerotic plaques.

Results

The patients’ mean age was 54.5±10.6 years, and 60% of the patients were male. The CIMT was 0.81±0.47 mm (range, 0.35–2.50 mm). The group with atherosclerosis was characterized by older age compared with those without atherosclerosis. Patients with atherosclerosis showed much shorter durations of access patency than their counterparts in the nonatherosclerosis group (hazard ratio, 2.822; 95% confidence interval, 1.113–7.156; P=0.029). Moreover, being overweight was associated with a 2.47-fold (95% confidence interval, 1.101–5.548) increased primary access failure.

Conclusion

This study shows that atherosclerosis is associated with older age. Patients who are overweight and have atherosclerosis may have shortened access patency.

A new echocardiographic parameter of arterial stiffness in end-stage renal disease

BACKGROUND

Cardiovascular disease is the leading cause of death among patients with end-stage renal disease (ESRD). Arterial stiffness is an independent predictive parameter of overall and cardiovascular mortality in these patients. However, the defined procedures for the measurement of arterial stiffness are time consuming and not practical in daily practice.

METHODS

The study population included 50 patients with ESRD who were treated with hemodialysis (HD; n=23) or peritoneal dialysis (PD; n=27) and 70 age- and sex-matched control subjects. Aortofemoral pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and color M-mode propagation velocity of the descending aorta (aortic propagation velocity, APV) were measured.

RESULTS

Compared to the control group, the patients with ESRD had significantly lower APV (46.4 ± 12.4 vs. 58.5 ± 8.5, p < 0.01) and higher PWV (10.5 ± 2.5 vs. 9.2 ± 1.2, p < 0.01) and CIMT (0.66 ± 0.15 vs. 0.43 ± 0.06, p < 0.01) measurements. There were significant correlations between APV and CIMT (r = - 0.769, p < 0.001), APV and PWV (r = - 0.682, p < 0.001), and PWV and CIMT (r = 0.564, p < 0.001). There were no significant differences in APV and PWV between the PD and HD patients.

CONCLUSION

Arterial stiffness is an important indicator of atherosclerosis and arterial aging in patients with ESRD. The measurement of APV is an easy and practical new echocardiographic method and may be used to identify arterial stiffness in these patients.

Subclinical Atherosclerosis, Endothelial Function, and Serum Inflammatory Markers in Chronic Kidney Disease Stages 3 to 4

Different inflammatory markers, brachial artery flow-mediated dilatation (FMD), and brachial intima-media thickness (bIMT) were measured in 50 patients with chronic kidney disease (CKD) stages 3 to 4 with estimated glomerular filtration rate (eGFR) and 35 age- and gender-matched controls. The bIMT was significantly increased in the patients with CKD compared with controls (0.43 mm [0.42, 0.45] vs 0.34 mm [0.32, 0.36]; P < .001). There was no significant difference in FMD between the study groups (4.7% vs 5.3%; P = .56). There were significant correlations between bIMT and high-sensitive C-reactive protein, vascular cellular adhesion molecule 1, tumor necrosis factor, and interleukin 6 ( P < .05). However, eGFR adjusted for age and gender was the best predictor of bIMT. In conclusion, bIMT and inflammatory markers were increased in patients with CKD compared with the controls. Furthermore, significant correlations between bIMT and inflammatory activity in patients with CKD were observed. The eGFR adjusted for age and gender was the best predictor of bIMT.

Asymmetric dimethylarginine: a novel cardiovascular risk factor in end-stage renal disease

OBJECTIVE

This cross-sectional study explored the association between carotid intima-media thickness (CIMT) and the oxidative stress markers asymmetric dimethylarginine (ADMA) and homo cysteine in patients with end-stage renal disease who were on haemodialysis.

METHODS

A total of 30 patients undergoing chronic haemodialysis treatment were recruited to this study. Homocysteine and ADMA levels were determined using a fluorescence polarization immunoassay and an enzyme-linked immunosorbent assay, respectively. CIMT was measured as a marker of atherosclerosis using high-resolution ultrasonography and was performed after haemodialysis.

RESULTS

Significant positive correlations were found between CIMT and ADMA, and CIMT and duration of haemodialysis. Linear regression analysis showed that ADMA level and age were significant independent determinants of CIMT, whereas homo cysteine was not.

CONCLUSIONS

The relationship demonstrated between plasma ADMA and carotid artery thickening suggests that ADMA may be a novel marker of atherosclerosis in patients on haemodialysis.

Prognostic value of 48-hour ambulatory blood pressure measurement and cardiovascular mortality in hemodialysis patients

BACKGROUND

Hypertension is common and contributes to high cardiovascular morbidity and mortality in hemodialysis (HD) patients. It is unknown which blood pressure (BP) better defines the influence on cardiovascular mortality. The purpose of our study was to analyze the relationship between various BP measurements, traditional risk factors, markers of asymptomatic atherosclerosis [left ventricular mass (LVM), carotid intima media thickness (IMT)], and cardiovascular mortality in HD patients.

METHODS

Seventy-three patients (44 males and 29 females; mean age: 54.2 years) were included. BP was measured before and after HD and 48-hour ambulatory blood pressure monitoring (ABPM) was performed. Using sonography, the LVM index and carotid IMT were measured.

RESULTS

During a follow-up period up to 3,664 days, 28 patients died - 16 of them from cardiovascular causes. In a Cox regression model, which included age, gender, smoking, diabetes, sensitive C-reactive protein, albumin, hemoglobin, troponin T, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, calcium, phosphorus, carotid IMT, and LVM index, only 48-hour systolic ABPM (p = 0.037) and 48-hour diastolic ABPM (p = 0.006) turned out to be independent predictors of cardiovascular death.

CONCLUSION

Only 48-hour ABPM and not single BP measurements before or after HD were associated with cardiovascular mortality in HD patients.

Carotid artery intima media thickness as a surrogate marker of atherosclerosis in patient with chronic renal failure on hemodialysis

BACKGROUND

In patients with chronic renal failure (CRF), carotid artery intima media thickness (CAIMT) is increased when the patients are on hemodialysis. Vascular events caused by atherosclerosis are the major cause of death in patients undergoing hemodialysis.

AIMS

This study was done to find out the relationship between carotid artery intima media thickness and hemodialysis in chronic renal failure patients independent of classical risk factors and also the relationship between CAIMT of hemodialyzed patients and nonhemodialyzed CRF patients.

MATERIALS AND METHODS

In this observational study, CAIMT of 78 CRF patients was examined by B-mode ultrasonography. Glomerular filtration rate (GFR) was calculated by using the "Modification of Diet in Renal Disease" formula. CRF patients, who had been on regular hemodialysis treatment (treated thrice weekly) for at least 6 months, were identified as hemodialyzed patients. Data were analyzed by software Statistical package for the social Sciences (SPSS) (17(th) version).

RESULTS

There was significant positive correlation between CAIMT and hemodialysis (P=0.045) independent of traditional risk factors. Hemodialyzed patients had higher mean CAIMT (1136.30±21.21 μm, P<0.001) than mean CAIMT of age and sex matched nondialyzed patients (959.30±23.01 μm).

CONCLUSION

Hemodialysis is an independent risk factor for atherosclerosis in CRF patents. Hemodialyzed patients have significantly higher CAIMT than nondialyzed CRF patients.

Chronic kidney disease, dyslipidemia, and atherosclerosis

Patients with chronic kidney disease (CKD) are at an increased risk not only for end-stage kidney disease (ESKD) but also for cardiovascular disease (CVD). In this review article, we summarize the current evidence of CKD as a high-risk condition for CVD based on reports from Japan and other countries to draw attention to the close clinical association between CKD and CVD. Several epidemiologic studies have shown that the presence of CKD and reduced renal function are independent predictors of CVD also in Japan. According to a post-hoc analysis of CASE-J, the power of CKD as a predictor of CVD is as strong as diabetes mellitus and a previous history of ischemic heart disease. CKD worsens classical risk factors including hypertension and dyslipidemia, and dyslipidemia is associated with increased thickness and stiffness of large arteries independent of major confounders. A post-hoc analysis of MEGA indicates that lipid-lowering therapy with statins reduces the risk of CVD, and that it appears to be more efficacious in patients with than without CKD. These reports from Japan and other countries suggest that CKD should be regarded as a high-risk condition comparable to diabetes mellitus, and that strict control of dyslipidemia would be beneficial in preventing CVD, at least early stages of CKD.

Sevelamer carbonate in the treatment of hyperphosphatemia in patients with chronic kidney disease on hemodialysis

Sevelamer carbonate is an anion exchange pharmaceutical, developed to improve on the performance of the non-absorbable, non-calcium, and metal-free phosphate binder sevelamer hydrochloride. Sevelamer carbonate is expected not to worsen metabolic acidosis, as previously reported during long-term treatment with sevelamer hydrochloride in hemodialysis (HD) patients. Carbonate is the alternate counterion to chloride on the sevelamer polymeric backbone, but the active poly(allylamine) responsible for phosphate (PO₄) binding remains unaltered. Therefore, sevelamer carbonate is expected to reduce elevated serum phosphorus level, similarly to sevelamer hydrochloride. Sevelamers are prescribed in uremic HD patients to control hyperphosphatemia, but the carbonate has also been proposed for the treatment of chronic kidney disease (CKD) non-dialysis patients. Although hyperphosphatemia is regarded as a main contributor to increased mortality in the HD population because of cardiovascular calcification, metabolic acidosis has also been advocated as a major player in the increased mortality in this population, by engendering malnutrition, negative nitrogen balance, and inflammation. This paper reviews the evidence showing that sevelamer carbonate is as good as sevelamer hydrochloride in terms of hyperphosphatemia control in CKD, but with a better outcome in serum bicarbonate balance.

Endothelial function and oxidative stress in chronic kidney disease of varying severity and the effect of acute hemodialysis

AIM

Oxidative stress (OS) and endothelial dysfunction are implicated in accelerated atherosclerosis in chronic kidney disease (CKD). We assessed endothelial function, OS, and carotid intimal medial thickness (CIMT) and their correlates in 44 CKD stage 5 patients (group III) before and after hemodialysis (HD), 40 patients of CKD stages 3 and 4 (group II), and 25 matched controls (group I).

METHODS

OS was measured by serum concentration of antioxidants; vitamin C and fractional reducing ability of plasma (FRAP) and pro-oxidant; thiobarbituric acid reactive substances (TBARS). Ultrasonography of carotid artery for CIMT and of brachial artery for flow-mediated dilatation (endothelium-dependent dilatation, EDD) was done.

RESULTS

TBARS increased significantly with severity of CKD. Antioxidants FRAP and vitamin C were significantly lower in CKD patients as compared with controls, but there was no significant difference between groups II and III. EDD decreased significantly with severity of CKD, whereas CIMT though higher in CKD patients as compared with controls was not significantly different between groups II and III. After a session of HD as compared with predialysis, levels of TBARS decreased, whereas those of FRAP, vitamin C, and EDD increased. On multivariate analysis, there was negative correlation of TBARS with glomerular filtration rate (GFR), serum albumin, hemoglobin, and EDD. Vitamin C had positive correlations with GFR, serum albumin, hemoglobin, and EDD. EDD had direct correlation with GFR, whereas CIMT correlated negatively with EDD.

CONCLUSIONS

Endothelial dysfunction and OS occur early in CKD, are closely related to each other and structural atherosclerosis, and are proportional to decline in GFR.

Advanced glycation end products, carotid atherosclerosis, and circulating endothelial progenitor cells in patients with end-stage renal disease

Numbers of endothelial progenitor cells (EPCs) have been shown to be decreased in subjects with end-stage renal disease (ESRD), the mechanism of which remained poorly understood. In this study, mutual association among circulating EPC levels, carotid atherosclerosis, serum pentosidine, and skin autofluorescence, a recently established noninvasive measure of advanced glycation end products accumulation, was examined in 212 ESRD subjects undergoing hemodialysis. Numbers of circulating EPCs were measured as CD34+ CD133+ CD45(low) VEGFR2+ cells and progenitor cells as CD34+ CD133+ CD45(low) fraction by flow cytometry. Skin autofluorescence was assessed by the autofluorescence reader; and serum pentosidine, by enzyme-linked immunosorbent assay. Carotid atherosclerosis was determined as intimal-medial thickness (IMT) measured by ultrasound. Circulating EPCs were significantly and inversely correlated with skin autofluorescence in ESRD subjects (R = -0.216, P = .002), but not with serum pentosidine (R = -0.079, P = .25). Circulating EPCs tended to be inversely associated with IMT (R = -0.125, P = .069). Intimal-medial thickness was also tended to be correlated positively with skin autofluorescence (R = 0.133, P = .054) and significantly with serum pentosidine (R = 0.159, P = .019). Stepwise multiple regression analyses reveal that skin autofluorescence, but not serum pentosidine and IMT, was independently associated with low circulating EPCs. Of note, skin autofluorescence was also inversely and independently associated with circulating progenitor cells. Thus, tissue accumulated, but not circulating, advanced glycation end products may be a determinant of a decrease in circulating EPCs in ESRD subjects.

Impact of cytokine genotype on cardiovascular surrogate markers in hemodialysis patients

BACKGROUND/AIMS

Cytokine gene polymorphisms have been implicated as potential genetic risk factors for cardiovascular diseases (CVDs). Atherosclerosis and left ventricular hypertrophy (LVH) are surrogate markers for CVDs in uremic patients. The aim of this study was to assess the role of cytokine gene polymorphisms in carotid intima-media thickness (CIMT) and left ventricular mass index (LVMI) progression in nondiabetic hemodialysis (HD) patients.

METHODS

About 102 nondiabetic patients on maintenance HD were included in this study. Patients were followed up for 2 years. Genetic polymorphisms of TNF-alpha (-308 G/A, -238A/G) and IL-10 (-1082 A/G, -819 C/T, -592 A/C) were determined by polymerase chain reaction. Biochemical parameters and inflammatory markers and ambulatory blood pressure (BP) measurements were determined during the study period. CIMT and LVMI were also determined at baseline and after the first and second year.

RESULTS

Cardiovascular risk factors did not differ between TNF-alpha -308 high-/low-producer genotype groups. However, CIMT and LVMI progression were detected at higher levels in patients with high-producer genotypes (AA+AG) than in patients with the low-producer genotype (GG) during the study period. The TNF-alpha -308 G/A polymorphism was closely associated with C-reactive protein (CRP), a marker of systemic inflammation in the study population. Analysis also showed that the combination of high production of TNF-alpha and low production of IL-10 was associated with higher average IMT and LVMI progression and elevated average CRP levels compared with a combination of low production of TNF-alpha and high production of IL-10.

CONCLUSION

Polymorphisms in inflammatory genes may represent an additional factor affecting inflammation and CVD progression in nondiabetic HD patients.

[Cognitive impairment and chronic kidney disease: which links?]

Ageing of the population leads to an increase of cognitive disorders and chronic renal failure incidence. Compared to the general population, prevalence of cognitive impairment is more important in renal failure patients, especially in dialyzed patients. No direct link has been established between renal failure and cognitive impairment. The care of older and older patients and the high frequency of vascular risk factors, in particular hypertension and diabetes, partially explain the prevalence of vascular dementia and Alzheimer disease in this population. Other factors as the anemia, phosphocalcic metabolism disorders facilitate the cognitive impairment. The present work reviews the links existing between chronic renal failure and cognitive impairment.

“Does chronic kidney disease define a particular risk pattern of cerebral vessels modifications in patients with symptomatic ischemic cerebrovascular disease?”

Cardiovascular complications, including stroke, may be attributed the highest rate of morbidity and mortality in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the prevalence of CKD in patients with symptomatic ischaemic cerebrovascular disease and to establish of whether CKD may define a particular risk pattern of cerebral vessels modifications in this category of patients. The prevalence of CKD was evaluated in 590 consecutive patients with symptomatic ischaemic cerebrovascular disease admitted to a department of neurology. The types of stroke, the vascular territories, the vascular modifications and the haemodynamic changes (resistance index- RI) found by neurosonology (extracranial and transcranial Doppler ultrasound) were analysed in relation to classic and non-classic cerebrovascular risk factors, as well as to stages of CKD (defined by estimated glomerular filtration rate-eGFR-MDRD4 formula-K/DOQI 2002). The prevalence of CKD in the studied patients was 70.84%. Atherosclerosis in a diffuse pattern was detected in 79.7% of CKD patients, while carotid artery stenoses were found in 10% of cases, occlusions- 5.3%, stenoses + occlusions-1.2%, and multiple stenoses- 3.8% of cases. The RI evaluated in the internal carotid arteries correlated with fibrinogen(P<0.0001) and GFR(P<0.0001), while IR in the middle cerebral arteries correlated with fibrinogen(P<0.05), C-reactive protein(P<0.0001), and GFR(P<0.0001). There is a strong relation between symptomatic cerebrovascular disease and CKD, a fact demonstrated by the increased prevalence of CKD in these patients and by the severity of the cerebral vessels lesions.