Inflammation, arteriosclerosis, and cardiovascular therapy in hemodialysis patients

Pathophysiology and Clinical Impacts of Chronic Kidney Disease on Coronary Artery Calcification

The global prevalence of chronic kidney disease (CKD) has increased in recent years. Adverse cardiovascular events have become the main cause of life-threatening events in patients with CKD, and vascular calcification is a risk factor for cardiovascular disease. Vascular calcification, especially coronary artery calcification, is more prevalent, severe, rapidly progressive, and harmful in patients with CKD. Some features and risk factors are unique to vascular calcification in patients with CKD; the formation of vascular calcification is not only influenced by the phenotypic transformation of vascular smooth muscle cells, but also by electrolyte and endocrine dysfunction, uremic toxin accumulation, and other novel factors. The study on the mechanism of vascular calcification in patients with renal insufficiency can provide a basis and new target for the prevention and treatment of this disease. This review aims to illustrate the impact of CKD on vascular calcification and to discuss the recent research data on the pathogenesis and factors involved in vascular calcification, mainly focusing on coronary artery calcification, in patients with CKD.

The effects of curcumin-containing supplements on inflammatory biomarkers in hemodialysis patients: A systematic review and meta-analysis

In the past decade, the effect of curcumin or turmeric supplementation on many aspects of health status in different populations has been evaluated. In the present study, a systematic review and meta-analysis were conducted to estimate the effect of curcumin administration on inflammatory markers in hemodialysis (HD) patients. A systematic search was performed in MEDLINE, EMBASE, Scopus, and Clarivate Analytics Web of Science databases from 1997 until June2022 for terms related to curcumin/turmeric and hemodialysis (HD). Randomized, double-blind/single-blind studies examining the effects of curcumin/turmeric on the inflammation of HD participants older than 18 years were considered eligible for inclusion. Data were pooled using the weighted mean difference (WMD) and 95% CI as the summary statistic, considering a random-effects analysis model. The data that were pooled from nine studies with 472 patients indicated that curcumin-containing supplement had significant effect on serum C-reactive protein (CRP) levels (WMD = -3.3 mg/L; 95% CI: -5.4 to -1.3; p < 0.001, I²  = 76.7%, 8 studies, 467 participants), and interlukine-6 (IL-6) levels (SMD: -0.4; 95% CI: -0.8 to -0.07; p = 0.02, I²  = 31.6%, 3 studies, 153 participants) compared control group. Although curcumin intervention could not change tumor neurosis factor-α (TNF-α) concentration (SMD = -0.3; 95% CI: -0.7 to 0.04; p = 0.08, I²  = 25.3%, 3 studies, 153 participants), when compared with the placebo group. Our study's main limitations were small number of studies, overall high risk of bias in the included trials, and high heterogeneity in some results. The present meta-analysis suggested that intervention with curcumin-containing supplements was associated with a significant reduction in serum hs-CRP and IL-6 concentrations in HD patients. The curcumin intervention in the reduction of hs-CRP levels was greater than the minimal clinically important difference (MCID) for CRP (0.5 mg/L), which can be helpful in physicians' clinical decisions.

Utility of Geriatric Nutritional Risk Index in Patients with Chronic Kidney Disease: A Mini-Review

Chronic kidney disease (CKD) is one of the most significant risk factors for cardiovasculardisese. Malnutrition has been recognized as a significant risk factor for cardiovascular disease in patients with CKD, including those on chronic dialysis. Current studies showed higher all-cause and cardiovascular mortality rates in patients with CKD and malnutrition. Geriatric nutritional risk index (GNRI), a simple and validated nutritional screening measure for both elderly people and patients on dialysis, is based only on three objective parameters: body weight, height, and serum albumin level. Recently, we demonstrated that the cutoff GNRI for predicting all-cause and cardiovascular mortality was 96 in patients on hemodialysis. Moreover, together with left ventricular hypertrophy and low estimated glomerular filtration rate, the utility of GNRI as a significant determinant of cardiovascular events was demonstrated in non-dialysis-dependent patients with CKD. In the present review, we summarize available evidence regarding the relationship of GNRI with all-cause and cardiovascular mortality in patients with CKD including those on dialysis.

Peritoneal-Membrane Characteristics and Hypervolemia Management in Peritoneal Dialysis: A Randomized Control Trial

Excessive bodily-fluid retention is the major cause of hypertension and congestive heart failure in patients with end-stage renal disease. Compared to hemodialysis, peritoneal dialysis (PD) uses the abdominal peritoneum as a semipermeable dialysis membrane, providing continuous therapy as natural kidneys, and having fewer hemodynamic changes. One major challenge of PD treatment is to determine the dry weight, especially considering that the speed of small solutes and fluid across the peritoneal membrane varies among individuals; considerable between-patient variability is expected in both solute transportation and ultrafiltration capacity. This study explores the influence of peritoneal-membrane characteristics in the hydration status in patients on PD. A randomized control trial compares the bioimpedance-assessed dry weight with clinical judgment alone. A high peritoneal membrane D/P ratio was associated with the extracellular/total body water ratio, dialysate protein loss, and poor nutritional status in patients on PD. After a six-month intervention, patients with monthly bioimpedance analysis (BIA) assistance had better fluid (−1.2 ± 0.4 vs. 0.1 ± 0.4 kg, p = 0.014) and blood-pressure (124.7 ± 2.7 vs. 136.8 ± 2.8 mmHg, p < 0.001) control; however, hydration status and blood pressure returned to the baseline after we prolonged BIA assistance to a 3-month interval. The dry-weight reduction process had no negative effect on residual renal function or peritoneal-membrane function. We concluded that peritoneal-membrane characteristics affect fluid and nutritional status in patients on PD, and BIA is a helpful objective technique for fluid assessment for PD.

Chronic Kidney Disease-Mineral and Bone Disorders: Pathogenesis and Management

The key players of the chronic kidney disease-mineral and bone disorders (CKD-MBD) are calcium, phosphate, PTH, FGF23, and the vitamin D hormonal system. The progressive reduction of kidney function greatly modifies the tightly interrelated mechanisms that control these parameters. As a result, important changes occur in the bone and mineral hormonal axis, leading to changes in bone turnover with relevant consequences in clinical outcomes, such as decrease in bone mass with increased bone fragility and bone fractures and increased vascular and valvular calcification, also with great impact in the cardiovascular outcomes. So far, the knowledge of the mineral and bone disorders in CKD and the increased variety of efficacious therapies should lead to a better prevention and management of CKD-MBD.

Circulating angiopoietin-like protein 2 levels and arterial stiffness in patients receiving maintenance hemodialysis: A cross-sectional study

BACKGROUND AND AIMS

Chronic low-grade inflammation is receiving much attention as a critical pathology that induces various aging phenotypes, a concept known as "inflammaging". Uremic patients undergoing hemodialysis therapy show vascular aging phenotypes characterized by greater arterial stiffness and calcification compared to healthy controls of the same generation. In the current study, we investigated whether levels of inflammaging markers in the circulation were associated with vascular aging phenotypes in hemodialysis patients, as estimated by the cardio-ankle vascular index (CAVI).

METHODS

We conducted a multicenter cross-sectional study of 412 patients receiving hemodialysis and evaluated the relationship between circulating hs-CRP or ANGPTL2 levels, as markers of inflammaging, and CAVI.

RESULTS

Of 412 patients, 376 were analyzed statistically. While circulating hs-CRP levels had no significant association with CAVI, generalized linear models revealed that high circulating ANGPTL2 levels were significantly associated with increasing CAVI after adjustment for classical metabolic factors and hemodialysis-related parameters [β 0.63 (95%CI 0.07-1.18)]. Exploratory analysis revealed that high circulating ANGPTL2 levels were also strongly associated with increased CAVI, particularly in patients with conditions of increased vascular mechanical stress, such elevated blood pressure [β 1.00 (95%CI 0.23-1.76)], elevated pulse pressure [β 0.75 (95%CI 0.52-0.98)], or excess body fluid [β 1.25 (95%CI 0.65-1.84)].

CONCLUSIONS

We conclude that circulating levels of ANGPTL2 rather than hs-CRP are positively associated with CAVI in the uremic population and that ANGPTL2 could be a unique marker of progression of vascular aging in patients receiving hemodialysis.

The Influence of Dialytic Modality on Arterial Stiffness, Pulse Wave Reflections, and Vasomotor Function

Background

Measurements of aortic stiffness [aortic pulse wave velocity (PWV) and augmentation index (AIx)] have been established as powerful predictors of survival on hemodialysis (HD). Abnormal endothelial-dependent and endothelial-independent vascular reactivity and increased arterial stiffness are commonly described in HD patients. There is, however, a lack of information on the comparative impact of different renal replacement therapies (RRTs) on PWV and AIx, and how these different methods might influence endothelial-dependent abnormal vasodilatation.

Objective

To describe in a cross-sectional design arterial compliance and distensibility in continuous ambulatory peritoneal dialysis (CAPD) versus HD versus renal transplant (RTx) patients, compared with age- and blood pressure-matched essential hypertensive controls. The PWV and aortic AIx were determined from contour analysis of arterial waveforms recorded by applanation tonometry in 40 CAPD, 41 HD, 20 RTx patients (with normal serum creatinine), and 20 controls with essential hypertension (all normotensive under treatment). Endothelial-dependent and endothelial-independent vascular reactivities were assessed by changes in AIx following challenges with inhaled salbutamol and sublingual nitroglycerin respectively.

Results

CAPD patients had significantly stiffer arteries than all other categories. The PWV was 8.29 ± 1.09 m/second in CAPD patients, significantly higher ( p < 0.05) compared to HD subjects (7.19 ± 1.87 m/s). Both dialysis subgroups had significantly higher PWV values compared to RTx patients (6.59 ± 1.62 m/s) and essential hypertensive controls (6.34 ± 1.32 m/s), p < 0.05. The AIx had a profile similar to PWV in different RRTs. All groups with the exception of CAPD subjects had a significant decrease in AIx following salbutamol. Moreover, the vasodilatation induced by either nitroglycerin or salbutamol was significantly blunted compared to HD. Overall, both dialysis categories had more abnormal responses compared to RTx patients and essential hypertensive controls.

Conclusion

CAPD is associated with stiffer arteries and more profoundly abnormal endothelial-dependent vasomotor function, compared to matched HD subjects. These differences in arterial physical properties might explain differences seen in cardiac structure and function between the RRTs.

Risk factors for heart valve calcification in chronic kidney disease

Cardiovascular disease (CVD) is a common cause of death in patients with chronic kidney disease (CKD). Aortic and mitral valve calcification (AVC and MVC, respectively) are critical indicators of CVD and all-cause mortality in CKD patients.We conducted a single center retrospective study of Chinese inpatients with CKD to identify risk factors associated with valve calcification (VC).Of 288 enrolled CKD patients, 22.9% had VC, all of which exhibited AVC, while 21.2% exhibited MVC. The VC group were significantly older than the non-VC group (70.42 ± 11.83 vs 56.47 ± 15.00, P < .001), and contained more patients with history of coronary artery disease (12.1% vs 4.5%, P = .025) or stroke (18.2% vs 5.4%, P < .001). Subjective global assessment scoring indicated that more VC patients were mid/severely malnourished. Levels of prealbumin, cholesterol (Ch), triglycerides, low-density lipoprotein (LDL), apolipoprotein E, ejection fraction, and fraction shortening were significantly lower, and blood C reactive protein, IL-6, left ventricular internal end diastole diameter measured in end diastole, and interventricular septum thickness (IVST) levels were significantly higher in the VC group. Bone metabolism did not differ significantly between the 2 groups. Multivariable logistic regression analysis indicated that age, blood Ch, and LDL levels were significantly associated with VC.Advanced age, increased IVST, hypocholesterolemia, and hyper-LDL cholesterolemia were key risk factors for VC in Han patients with CKD.

Increased Inflammatory Response in Association with the Initiation of Hemodialysis Compared with Peritoneal Dialysis in a Prospective Study of End-Stage Kidney Disease Patients

BACKGROUND

Large epidemiological studies have demonstrated an early survival advantage with the initiation of peritoneal dialysis (PD) compared to haemodialysis (HD). Chronic inflammation may contribute to atherosclerosis and cardiovascular (CVD) mortality in end-stage kidney disease (ESKD). We hypothesize that the initiation of HD in ESKD patients is associated with a greater inflammatory response compared with PD.

AIMS

To examine the effects of initiating HD and PD upon inflammation and CVD risk markers in ESKD patients.

METHODS

We performed a pilot prospective study on 75 predialysis CKD stage-5 subjects comparing the effects of HD and PD upon high sensitivity C-reactive protein (hsCRP), interleukin(IL)-12, IL-18 and pulse wave velocity (PWV). Study visits were conducted 3 - 6 months before (baseline) and after (follow-up) initiation of dialysis RESULTS: Thirty-nine and 36 patients were initiated on HD and PD respectively. HD patients were older than PD patients (65.1 ± 2.1 vs 57.7 ± 2.7 years; p = 0.03) but had similar baseline systolic blood pressure (SBP), pulse pressure (PP), hsCRP, IL-12, IL-18, and PWV. At follow-up, HD patients had significantly increased hsCRP levels [5.2(3.7, 7.3) vs 1.7(1.0, 2.8)g/L; p < 0.001] compared to PD. Follow-up blood pressure, IL-12, IL-18, and PWV were similar between groups. A significant association remained between hsCRP and HD after adjustment for age, previous CVD, and residual urine output.

CONCLUSION

The initiation of HD was associated with significantly increased hsCRP compared to PD. Further study is required to determine the plausibility of inflammation as a potential underlying contributor to the observed early mortality difference between dialysis modalities.

Acute phase proteins as prospective risk markers for arterial stiffness: The Malmö Diet and Cancer cohort

BACKGROUND AND OBJECTIVES

Arterial stiffness plays a significant role in the development and progression of adverse cardiovascular events and all-cause mortality. This observational study aims to explore the relationship between six acute phase proteins namely, ceruloplasmin, alpha-1-antitrypsin, orosomucoid, haptoglobin, complement C3 and C-reactive protein (CRP), and carotid-femoral pulse wave velocity (c-f PWV) in a population-based cohort, and to also explore the effect of low-grade inflammation on the relationship between diabetes and c-f PWV.

METHOD

The study consisted of participants from the Malmö Diet and Cancer study with data from baseline examinations (1991-1994) and follow-up examinations (2007-2012). Arterial stiffness was measured at follow-up by determining c-f PWV. After excluding participants with missing data, the total study population included 2338 subjects. General linear models were used to assess the relationship between baseline acute phase proteins and c-f PWV.

RESULTS

After adjusting for traditional risk factors the participants in the 4th quartile vs 1st quartile of alpha-1-antitrypsin (geometric mean: 10.32 m/s vs 10.04 m/s) (p<0.05), C3 (10.35 m/s vs 10.06 m/s) (p<0.05) and CRP (10.37 m/s vs 9.96 m/s) (p<0.001) showed significant association with c-f PWV. Diabetes at follow-up was also associated with high c-f PWV, however, this relationship was independent of low grade inflammation.

CONCLUSION

Alpha-1-antitrypsin, C3 and CRP are associated with arterial stiffness. The results indicate that low grade inflammation is associated with arterial stiffness in addition to established cardiovascular risk factors.

The importance of accurate measurement of aortic stiffness in patients with chronic kidney disease and end-stage renal disease

Cardiovascular (CV) disease is the leading cause of death in chronic kidney disease (CKD) and end-stage renal disease (ESRD). A key driver in this pathology is increased aortic stiffness, which is a strong, independent predictor of CV mortality in this population. Aortic stiffening is a potentially modifiable biomarker of CV dysfunction and in risk stratification for patients with CKD and ESRD. Previous work has suggested that therapeutic modification of aortic stiffness may ameliorate CV mortality. Nevertheless, future clinical implementation relies on the ability to accurately and reliably quantify stiffness in renal disease. Pulse wave velocity (PWV) is an indirect measure of stiffness and is the accepted standard for non-invasive assessment of aortic stiffness. It has typically been measured using techniques such as applanation tonometry, which is easy to use but hindered by issues such as the inability to visualize the aorta. Advances in cardiac magnetic resonance imaging now allow direct measurement of stiffness, using aortic distensibility, in addition to PWV. These techniques allow measurement of aortic stiffness locally and are obtainable as part of a comprehensive, multiparametric CV assessment. The evidence cannot yet provide a definitive answer regarding which technique or parameter can be considered superior. This review discusses the advantages and limitations of non-invasive methods that have been used to assess aortic stiffness, the key studies that have assessed aortic stiffness in patients with renal disease and why these tools should be standardized for use in clinical trial work.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Long-term effects of angiotensin II blockade with irbesartan on inflammatory markers in hemodialysis patients: A randomized double blind placebo controlled trial (SAFIR study)

INTRODUCTION

Low-grade chronic inflammation is common in hemodialysis (HD) patients. Previous studies suggest an anti-inflammatory effect of angiotensin II receptor blocker (ARB) treatment. The aim of this study was to compare the effect of ARB vs. placebo on plasma concentrations of inflammatory markers in HD patients.

METHODS

Adult HD patients were randomized for double-blind treatment with the ARB irbesartan 150-300 mg/day or placebo. At baseline, 1 week, 3, 6, 9, and 12 months plasma high sensitivity C-reactive protein (hsCRP), interleukin (IL)-1β, IL-6, IL-8, IL-18, and transforming growth factor-β (TGF-β) were measured using Luminex and enzyme-linked immunosorbent assay (ELISA) technology.

FINDINGS

Eighty-two patients were randomized (placebo/ARB: 41/41). The groups did not differ in initial levels of any of the inflammatory markers (placebo/ARB median(range)): hsCRP 3.3(0.2-23.4)/2.7(0.2-29.6) μg/mL; IL-1β 1.1(0.0-45.9)/1.1(0.0-7.2) pg/mL; IL-6 10(1-90)/12(1-84) pg/mL; IL-8 31(9-134)/34(5-192) pg/mL; IL-18 364(188-1343)/377(213-832) pg/mL; TGF-β 3.2(0.8-13.9)/3.6(1.3-3.8) ng/mL. Overall, there was no significant difference in hsCRP, IL-6, IL-8, and TGF-β between placebo and ARB-treated patients during the study period, and hsCRP, IL-6, IL-8, and TGF-β were relatively stable during the study period (P ≥ 0.18 in all tests for parallel curves, equal levels, and constant levels). The IL-1β level was slightly different in the two groups over time, but not significantly (P = 0.09 in test for parallel curves) and it was also relatively stable during the study period (P ≥ 0.49 in tests for equal levels and constant level). IL-18 was the only inflammatory marker which was not constant during the study period (P = 0.001 in test for constant level), but there was no significant difference between placebo and ARB-treated (P ≥ 0.51 in tests for parallel curves and equal levels).

DISCUSSION

Inflammatory biomarkers were neither acutely, nor in the long-term significantly affected by the ARB irbesartan. Our findings suggest that ARB treatment in HD patients does not offer protective anti-inflammatory effects.

Vascular alterations in apolipoprotein A-I amyloidosis (Leu75Pro). A case-control study

BACKGROUND

Among hereditary amyloidoses, apolipoprotein A-I (APO A-I) amyloidosis (Leu75Pro) is a rare, autosomal dominant condition in which renal, hepatic, and testicular involvement has been demonstrated.

OBJECTIVE

To investigate vascular structural as well as functional alterations.

METHODS

In 131 carriers of the amyloidogenic Leu75Pro APO A-I mutation (mean age 52 + 16 years, 56 women) and in 131 subjects matched for age, sex, body mass index and clinic blood pressure (BP), arterial stiffness (pulse wave velocity, PWV) and carotid intima-media thickness (IMT) were measured.

RESULTS

By definition no differences for age, sex, body mass index, and BP were observed. Meanmax IMT (Mmax-IMT) in the common (CC), bifurcation (BIF) and internal (ICA) carotid artery were comparable in the two groups. After adjustment for high-density lipoprotein cholesterol and renal function differences between the two groups, a lower meanmax-IMT was observed in APO A-I Leu75Pro mutation carriers than in controls (CC Mmax-IMT 0.87 ± 0.21 versus 0.93 ± 0.2 mm, p = 0.07; BIF Mmax-IMT 1.19 ± 0.48 versus 1.36 ± 0.46 mm, p = 0.025; ICA Mmax-IMT 0.9 ± 0.37 versus 1.02 ± 0.35 mm, p = 0.028). On the other hand, aortic stiffness was significantly greater in patients with APO A-I amyloidosis than controls (PWV 11.5 ± 2.9 and 10.7 ± 2.3 m/s, p < 0.05), even after adjusting for confounders.

CONCLUSIONS

In carriers of the amyloidogenic Leu75Pro APO A-I mutation, a significant increase in arterial stiffness is observed; on the contrary, carotid artery IMT is comparable to that of control subjects. These results may add significant information to the clinical features of this rare genetic disorder.

Dissociation between progression of coronary artery calcification and endothelial function in hemodialysis patients: a prospective pilot study

Chronic kidney disease profoundly disturbs calcium-phosphate metabolism and predisposes to premature atherosclerosis. Both coronary artery calcification (CAC) and endothelial dysfunction are common in hemodialysis (HD) patients. We hypothesized that a calcium-free phosphate binder would improve endothelial function and delay progression of vascular calcification in HD patients.

METHODS

This was a randomized parallel-group trial in HD patients comparing lanthanum carbonate (LC) with a non-LC phosphorus binders control group (non-LC) at a 1 : 1 randomization. CAC was obtained at baseline, 6, and 12 months, and endothelial function (brachial artery flow-mediated dilation - FMD) at baseline and 6 months.

RESULTS

13 patients were randomized (LC n = 7 and non-LC n = 6). CAC scores (Log ± SE) at baseline were 7.21 ± 0.62 (LC) and 6.07 ± 0.73 (control). CAC increased in the non-LC group (33 ± 17% and 77 ± 22% at 6 and 12 months), but tended to decrease in the LC group (-10 ± 11% and -2 ± 11% at 6 and 12 months). There was statistically less progression in CAC in the LC group compared to control at 6 (p = 0.002) and 12 months (p = 0.003). There was no difference between groups in FMD (p = 0.7). Markers of inflammation did not change significantly.

CONCLUSION

A slower rate of progression of CAC occurred in the LC group, independent of changes in FMD. This is the first study showing dissociation between progression of CAC and FMD in HD patients. Larger studies are warranted to elucidate the impact of different phosphate sequestration therapies on atherosclerosis in HD patients.

Selective improvement in renal function preserved remote myocardial microvascular integrity and architecture in experimental renovascular disease

AIM

Atherosclerotic renovascular disease (ARVD) may impair renal function and increase cardiovascular morbidity and mortality, but the mechanism by which ARVD impacts cardiovascular function is unclear. We tested the hypothesis that preservation of renal function can reverse cardiac dysfunction in ARVD.

METHODS AND RESULTS

Endothelial progenitor cells (EPC) were injected intra-renally (ARVD+EPC) after 6 weeks of swine ARVD (concurrent hypercholesterolemia and renovascular hypertension), and single-kidney function and myocardial blood-flow and microvascular permeability (MP) responses to adenosine were assessed using CT 4 weeks later. Myocardial microvascular density was evaluated by micro-CT. Inflammation and oxidative-stress were assessed in kidney venous and systemic blood samples. Normal and untreated ARVD pigs served as controls. Blood pressure was similarly increased in ARVD and ARVD+EPC. Compared to normal, ARVD showed lower glomerular filtration rate, elevated renal vein and systemic oxidized LDL (ox-LDL), aldosterone, uric acid, isoprostanes, transforming growth factor (TGF)-β, and interleukine-6. Renal vein ox-LDL and TGF-β showed a positive gradient across the stenotic kidney, indicating increased renal oxidative stress and fibrogenic activity. Furthermore, ARVD impaired myocardial blood-flow and MP response to adenosine, decreased microvascular density, and induced myocardial fibrosis. Improvement of renal function in ARVD+EPC decreased systemic aldosterone, inflammation, and oxidative stress, and improved myocardial microvascular integrity and density.

CONCLUSION

Selective improvement in renal function, which reduced renal and systemic oxidative stress and inflammation, preserved remote myocardial microvascular function and architecture, despite enduring hypertension. These findings underscore functionally important cardiorenal crosstalk possibly mediated by renal injury signals.

Arterial stiffness in chronic kidney disease: the usefulness of a marker of vascular damage

Increased arterial stiffness is a marker of vasculopathy in chronic kidney disease (CKD) patients, suggesting a significant cardiovascular damage. Detection of arterial stiffness provides physicians with useful prognostic information independent of traditional cardiovascular (CV) risk factors. In addition, this knowledge may help guide appropriate therapeutic choices and monitor the effectiveness of antihypertensive therapies. We review the relationship between arterial stiffness and CKD, as well as the prognostic implications of increased arterial stiffness and the potential therapeutic strategies to ameliorate arterial compliance and outcome in CKD.

Intracranial arterial calcification is highly prevalent in hemodialysis patients but does not associate with acute ischemic stroke

Intracranial arterial calcification (IAC) is associated with ischemic stroke in the general population but this relationship has not been examined in hemodialysis patients. We examined the factors associated with IAC and its relationship with acute ischemic stroke in this population. We retrospectively studied 490 head computed tomographic scans from 2225 hemodialysis patients presenting with neurological symptoms at our center (October 2005-May 2009). Intracranial arterial calcification was graded using a validated scoring system. Multivariate regression was used to examine the factors associated with the presence of IAC, its severity, and its ability to predict acute ischemic stroke. Weibull's survival models analyzed the relationship between IAC severity and survival. Ninety-five percent of patients with ischemic stroke had IAC vs. 83% in the nonstroke group (P=0.02). Intracranial arterial calcification severity increased with age (P<0.001), hemodialysis vintage (P<0.001), serum phosphate (P<0.05), and major comorbidities. In patients with multiple computed tomographic scans during the study period, increased IAC severity at baseline was predictive of acute ischemic stroke (P=0.05) on logistic regression analysis. High-grade and not low-grade IAC was associated with worse survival (P=0.008). Intracranial arterial calcification is highly prevalent in hemodialysis patients, especially in those with acute ischemic stroke. Its severity is prognostically significant and associated with risk factors for vascular calcification and may confer a greater risk of acute ischemic stroke. The mechanisms underlying the high incidence of ischemic stroke in this patient group require further comprehensive study.

Beyond conventional considerations: newer devices used in blood pressure measurement and management

Several noninvasive devices are now available to assess blood vessel structure and function and have been shown in longitudinal cohort studies to provide additional cardiovascular event prediction over that obtained by conventional brachial blood pressure (BP) measurements. Among these newer measurements are estimates of vascular stiffness (as determined by the pulse wave velocity in the aorta) and measures of pulse wave reflection. Pulse wave velocity, in particular, has been well studied in end-stage kidney (ESKD) populations where it predicts cardiovascular events and death independently of standard BP. In addition, there are minimum 3 devices, either marketed or used in clinical trials, that are useful in some clinical situations as an adjunct to drug therapy for managing high BP. This review will focus on the roles of these new technologies in evaluating and managing high BP, emphasizing the CKD/ESKD patient where possible, although data are limited in the kidney disease population when it comes to managing BP with these novel device approaches.

Malnutrition-inflammation modifies the relationship of cholesterol with cardiovascular disease

In moderate and severe CKD, the association of cholesterol with subsequent cardiovascular disease (CVD) is weak. We examined whether malnutrition or inflammation (M-I) modifies the risk relationship between cholesterol levels and CVD events in African Americans with hypertensive CKD and a GFR between 20 and 65 ml/min per 1.73 m². We stratified 990 participants by the presence or absence of M-I, defined as body mass index <23 kg/m² or C-reactive protein >10 mg/L at baseline. The primary composite outcome included cardiovascular death or first hospitalization for coronary artery disease, stroke, or congestive heart failure occurring during a median follow-up of 77 months. Baseline total cholesterol (212 ± 48 versus 212 ± 44 mg/dl) and overall incidence of the primary CVD outcome (19 versus 21%) were similar in participants with (n = 304) and without (n = 686) M-I. In adjusted analyses, the CVD composite outcome exhibited a significantly stronger relationship with total cholesterol for participants without M-I than for participants with M-I at baseline (P < 0.02). In the non-M-I group, the cholesterol-adjusted hazard ratio (HR) for CVD increased progressively across cholesterol levels: HR = 1.19 [95% CI; 0.77, 1.84] and 2.18 [1.43, 3.33] in participants with cholesterol 200 to 239 and ≥240 mg/dl, respectively (reference: cholesterol <200). In the M-I group, the corresponding HRs did not vary significantly by cholesterol level. In conclusion, the presence of M-I modifies the risk relationship between cholesterol level and CVD in African Americans with hypertensive CKD.

Effect of membrane permeability on inflammation and arterial stiffness: a randomized trial

BACKGROUND AND OBJECTIVES

Both larger molecule removal and dialyzer biocompatibility have been implicated in the high-flux hemodialysis (HD)-associated favorable outcome. In an attempt to delineate the effect of membrane permeability, we performed a randomized, crossover study to compare the inflammatory biomarkers, lipid profile, and aortic pulse wave velocity (PWV) of two dialyzers that are composed of identical membranes but with different flux characteristics.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Stable patients who had anuria and were on low-flux polysulfone membrane were randomly allocated either to HD with high-flux polyamide membrane (group A; 22 patients) or to HD with low-flux polyamide membrane (group B; 24 patients) for 24 weeks, then they were started on 24 weeks of the alternative HD treatment. Apart from the dialyzer, the dialysis prescription remained unchanged.

RESULTS

Nineteen patients from group A and 23 patients from group B completed the study. Predialysis beta(2)-microglobulin levels decreased significantly when using the high-flux polyamide membrane. No difference between membranes was observed for serum albumin, high-sensitivity C-reactive protein, fibrinogen, IL-6, triglycerides, HDL cholesterol, LDL cholesterol, and lipoprotein(a) during the study. A significant increase in aortic PWV, a marker of aortic stiffness, was noted after patients switched from high-flux to low-flux polyamide membranes. Similarly, the rate of change in aortic PWV was significantly decreased with the use of the high-flux polyamide membrane.

CONCLUSIONS

Our findings suggest that dialysis with polyamide membranes with different flux characteristics did not modify the inflammatory indices and lipid profile in stable HD patients; however, a seemingly beneficial effect on aortic stiffness was noted for patients who were maintained on high-flux polyamide membrane.

Aortic PWV in chronic kidney disease: a CRIC ancillary study

BACKGROUND

Aortic pulse wave velocity (PWV) is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end-stage renal disease receiving hemodialysis. Little data exist characterizing aortic stiffness in patients with chronic kidney disease (CKD) who are not receiving dialysis, and in particular the effect of reduced kidney function on aortic PWV.

METHODS

We performed measurements of aortic PWV in a cross-sectional cohort of participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study to determine factors which predict increased aortic PWV in CKD.

RESULTS

PWV measurements were obtained in 2,564 participants. The tertiles of aortic PWV (adjusted for waist circumference) were <7.7 m/s, 7.7-10.2 m/s, and >10.2 m/s with an overall mean (+/- s.d.) value of 9.48 +/- 3.03 m/s (95% confidence interval = 9.35-9.61 m/s). Multivariable regression identified significant independent positive associations of age, blood glucose concentrations, race, waist circumference, mean arterial blood pressure, gender, and presence of diabetes with aortic PWV and a significant negative association with the level of kidney function.

CONCLUSIONS

The large size of this unique cohort, and the targeted enrollment of CKD participants provides an ideal situation to study the role of reduced kidney function as a determinant of arterial stiffness. Arterial stiffness may be a significant component of the enhanced cardiovascular risk associated with kidney failure.

The chemokine monocyte chemoattractant protein-1 contributes to renal dysfunction in swine renovascular hypertension

Renal artery stenosis (RAS) causes renovascular hypertension and renal damage, which may result from tissue inflammation. We have previously shown that the kidney in RAS exhibits increased expression of monocyte chemoattractant protein (MCP)-1, but its contribution to renal injury remained unknown. This study tested the hypothesis that MCP-1 contributes to renal injury and dysfunction in the stenotic kidney.

METHODS

Kidney hemodynamics, function, and endothelial function were quantified in pigs after 10 weeks of experimental RAS (n = 7), RAS supplemented with the MCP-1 inhibitor bindarit (RAS + bindarit, 50 mg/kg/day orally, n = 6), and normal controls (n = 8). Renal inflammation was assessed by the immunoreactivity of MCP-1, its receptor chemotactic cytokine receptor 2, and NFkappaB, and oxidative stress by nicotinamide adenine dinucleotide phosphate-oxidase expression and in-situ superoxide production. Renal microvascular density was evaluated by micro-CT and fibrosis by trichrome staining, collagen-I immunostaining, and hydroxyproline content.

RESULTS

After 10 weeks of RAS, blood pressure was similarly elevated in RAS and RAS + bindarit. Compared with normal controls, stenotic RAS kidneys had decreased renal blood flow (5.4 +/- 1.6 vs. 11.4 +/- 1.0 ml/min/kg, P < 0.05) and glomerular filtration rate and impaired endothelial function, which were significantly improved in bindarit-treated RAS pigs (to 8.4 +/- 0.8 ml/min/kg, P < 0.05 vs. RAS). Furthermore, bindarit markedly decreased tubulointerstitial (but not vascular) oxidative stress, inflammation, and fibrosis, and slightly increased renal microvascular density. The impaired renovascular endothelial function, increased oxidative-stress, and fibrosis in the contralateral kidney were also improved by bindarit.

CONCLUSION

MCP-1 contributes to functional and structural impairment in the kidney in RAS, mainly in the tubulointerstitial compartment. Its inhibition confers renoprotective effects by blunting renal inflammation and thereby preserving the kidney in chronic RAS.

Cardio-ankle vascular index and ankle pulse wave velocity as a marker of arterial fibrosis in kidney failure treated by hemodialysis

BACKGROUND

Patients with kidney failure treated with hemodialysis have a high incidence of cardiovascular diseases caused by accelerated arteriosclerosis. However, accurate evaluation of the extent of arteriosclerosis is difficult. This study sought to compare the strength of predictions of arterial fibrosis by using a new parameter, the cardio-ankle vascular index (CAVI), versus pulse wave velocity (PWV) in patients with kidney failure treated with hemodialysis.

STUDY DESIGN

Diagnostic test study.

SETTING & PARTICIPANTS

103 patients with kidney failure undergoing surgical construction of an arteriovenous access for hemodialysis therapy.

INDEX TEST

CAVI and PWV.

REFERENCE TEST

Arterial fibrosis, evaluated by using Masson trichrome stain on part of the brachial artery obtained during surgery, expressed as percentage of fibrosis of the layer of vascular smooth muscle cells.

RESULTS

Median percentage of arterial stiffness was 52.85%. Mean PWV and CAVI were 18.3 +/- 5.6 (SD) m/s and 9.9 +/- 2.6, respectively. Multivariate regression analysis showed that arterial fibrosis was significantly associated with older age (0.247%/y; 95% confidence interval, 0.013 to 0.482) and CAVI (6.117%/unit; 95% confidence interval, 4.764 to 4.740), but not with systolic blood pressure (0.039%/mm Hg; 95% confidence interval, -0.076 to 0.153) or PWV (-0.044%/m/s; 95% confidence interval, -0.646 to 0.558). The area under the receiver operating characteristic curve to predict greater than median percentage of arterial stiffness was 0.892 for CAVI and 0.779 for PWV (P = 0.006).

LIMITATION

It is unclear whether arterial fibrosis of the brachial artery evaluated by using CAVI is applicable for arteriosclerosis of other arterial districts, and clinical outcomes were not evaluated in this study.

CONCLUSION

CAVI reflects the histological arterial fibrosis of hemodialysis patients and is a useful clinical marker for evaluating arterial stiffness in these patients.

Relations of inflammatory biomarkers and common genetic variants with arterial stiffness and wave reflection

Inflammation causes vascular dysfunction and perpetuates proatherosclerotic processes. We hypothesized that a broad panel of inflammatory biomarkers and single nucleotide polymorphisms in inflammatory genes is associated with vascular stiffness. We assessed 12 circulating inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin-6, intercellular adhesion molecule-1, lipoprotein-associated phospholipase-A2 [mass and activity], monocyte chemoattractant protein-1, myeloperoxidase, CD40 ligand, osteoprotegerin, P-selectin, and tumor necrosis factor receptor-II) in relation to tonometry variables (central pulse pressure, mean arterial pressure, forward pressure wave, reflected pressure wave, carotid-femoral pulse wave velocity, and augmentation index) measured in 2409 Framingham Heart Study participants (mean age: 60 years; 55% women; 13% ethnic/racial minorities). Single nucleotide polymorphisms (n=2195) in 240 inflammatory candidate genes were related to tonometry measures in 1036 white individuals. In multivariable analyses, biomarkers explained <1% of any tonometry measure variance. Applying backward elimination, markers related to tonometry (P<0.01) were as follows: tumor necrosis factor receptor-II (inversely) with mean arterial pressure; C-reactive protein (positively) and lipoprotein-associated phospholipase-A2 (inversely) with reflected pressure wave; and interleukin-6 and osteoprotegerin (positively) with carotid-femoral pulse wave velocity. In genetic association analyses, lowest P values (false discovery rate <0.50) were observed for rs10509561 (FAS), P=6.6x10(-5) for central pulse pressure and rs11559271 (ITGB2), P=1.1x10(-4) for mean arterial pressure. These data demonstrate that, in a community-based sample, circulating inflammatory markers tumor necrosis factor receptor-II (mean arterial pressure), C-reactive protein, lipoprotein-associated phospholipase-A2 activity (reflected pressure wave), interleukin-6, and osteoprotegerin (carotid-femoral pulse wave velocity) were significantly but modestly associated with measures of arterial stiffness and wave reflection. Additional studies are needed to determine whether variation in inflammatory marker genes is associated with tonometry measures.

Effect of sevelamer on aortic pulse wave velocity in patients on hemodialysis: a prospective observational study

Aortic stiffening and aortic calcification are risk factors for cardiovascular events in hemodialysis (HD) patients, and these 2 risk factors are interrelated. Sevelamer decreases aortic calcification but its effect on aortic stiffness has not been investigated previously. Thirteen HD patients commencing sevelamer treatment and 13 matched controls were followed for 11 months. Aortic pulse wave velocity (PWV), augmentation index (AIx), and levels of inhibitors of vascular calcification (fetuin-A, matrix-GLA-protein, osteoprotegerin/RANKL) were measured at baseline and at the end of follow-up, and the differences between the groups were compared. Determinants of the changes in PWV during follow-up were assessed by multivariate linear regression. At baseline, PWV was 9.93 (2.10) m/s in sevelamer-treated patients and 9.20 (2.84) m/s in control patients (p=0.464). By the end of follow-up, PWV decreased by 0.83 (2.3) m/s in sevelamer-treated patients while it increased by 0.93 (1.88) m/s in controls (p=0.042). The direction of changes in AIx were similar, but not statistically significant. There were no significant differences in the levels of inhibitors of calcification either at baseline or during follow-up. In multivariate linear regression sevelamer treatment, diabetes, heart rate, and C-reactive protein were related to the change in PWV. These data suggest that sevelamer treatment is associated with an improvement in aortic stiffness in HD patients, but it does not seem to affect serum levels of inhibitors of vascular calcification.

Disturbances of acquired immunity in hemodialysis patients

Acquired immunity disturbances in hemodialysis (HD) patients are many and diverse. They are caused by uremia per se, the HD procedure, chronic renal failure complications, and therapeutic interventions for their treatment. Current data suggest that acquired immunity disturbances in HD patients concern mainly the T-lymphocyte and the antigen-presenting cell (APC). The T-lymphocyte-dependent immune response is deficient, predisposing to infections and inadequate response to vaccinations. In addition, APCs are preactivated, which seems to be responsible for the malnutrition-inflammation-atherosclerosis syndrome, and also affects T-lymphocyte function. At the molecular level it is assumed that the interaction between the APC and the T-lymphocyte is impaired. This disturbance is likely to concern the signal that results from the interaction between the major histocompatibility complex:peptide complex on APC surfaces and T-cell receptors on T-lymphocyte surfaces, or the signal that results from the interaction among the co-receptors of these two cells. The aim of the present review was to collect and classify the available clinical and experimental data in this area. Although many pieces are still missing from the puzzle, a better understanding of the responsible molecular mechanisms, will potentially lead to increased survival and a better quality of life in HD patients.

Antihypertensive agents and arterial stiffness: relevance to reducing cardiovascular risk in the chronic kidney disease patient

PURPOSE OF REVIEW

Arterial stiffness is a sign of diffuse adventitial macrovascular disease. The purpose of the present review is to discuss, in patients with chronic kidney disease, the pathophysiology of increased arterial stiffness, the role of antihypertensive therapy on reduction of arterial stiffness, and the clinical ways by which the prognostication of cardiovascular disease in patients with chronic kidney disease can be refined using arterial stiffness monitoring.

RECENT FINDINGS

Arterial stiffness is increased with increasing prevalence of traditional cardiovascular risk factors. In patients with chronic kidney disease some unique factors further increase the risk of arterial stiffness, and include volume overload, activation of the renin-angiotensin system, anemia, and dysregulated mineral metabolism. Arterial stiffness is increased even in patients with early-stage chronic kidney disease. Blood pressure reduction when accompanied by a reduction in arterial stiffness is associated with improved prognosis. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can preferentially improve arterial stiffness, which may be an additional mechanism of cardiovascular protection with these agents.

SUMMARY

The impact of improvement in arterial stiffness with antihypertensive agents on cardiovascular outcomes needs well designed clinical trials.

Pulse Pressure Is an Independent Predictor of Aortic Stiffness in Patients with Mild to Moderate Chronic Kidney Disease

BACKGROUND

In patients with end-stage renal disease pulse wave velocity (PWV) has been widely assessed, but its behavior in mild to moderate chronic kidney disease (CKD) has been less investigated. We evaluated PWV in mild to moderate CKD.

METHODS

We studied 31 patients with grade II-IV CKD. Aortic PWV (aPWV), aortic and upper limb augmentation index, creatinine clearance, C-reactive protein, serum fibrinogen, interleukin-1, interleukin-6, tumor necrosis factor, albumin, total and high-density lipoprotein cholesterol and blood pressure were evaluated.

RESULTS

aPWV (7.95 +/- 0.64 m/s), but not augmentation index was significantly higher (p = 0.03) in CKD patients than age-matched healthy subjects (aPWV: 6.24 +/- 0.43 m/s; upper limb: 32.8 +/- 1.9; aortic: 27.7 +/- 1.9). At univariate regression analysis, aPWV was significantly correlated with age (r = 0.44; p = 0.013), interleukin-6 (r = 0.43; p = 0.027), pulse (r = 0.39; p = 0.029), systolic blood pressure (r = 0.37; p = 0.038) and tumor necrosis factor (r = 0.39; p = 0.029). At multivariate analysis, pulse pressure was the only significant independent determinant (beta = 0.37; p = 0.05) of aPWV.

CONCLUSION

The results of this study confirm an aPWV increase in mild to moderate CKD and emphasize association between pulse pressure and PWV, independently of renal failure.

Significant association of C-reactive protein with arterial stiffness in treated non-diabetic hypertensive patients

C-reactive protein (CRP) has been known to be associated with vascular inflammation and hypertension. Pulse wave velocity (PWV) increases according to the degree of the arterial stiffness in hypertension patients. Therefore, PWV may be correlated with CRP levels in treated hypertensive patients, irrespective of medication. We sought to determine whether there is a correlation between hsCRP and arterial stiffness in non-diabetic treated hypertensive patients, independent of cardiovascular risk factor. This study consisted of 424 non-diabetic patients at least 45-years-old who were being treated for hypertension. At the time of enrollment, the patients underwent a baseline laboratory assessment of C-reactive protein levels and pulse wave velocity (PWV). Heart to femoral PWV (hfPWV) and brachial to ankle PWV (baPWV) were used as a marker of arterial stiffness. Subjects were categorized according to tertiles of hsCRP level [Group 1: first tertile (0.20-0.46 mg/L), Group 2: second tertile (0.47-1.15 mg/L), Group 3: third tertile (1.17-9.71 mg/L)]. Group 1 consisted of 141 patients (mean age 58+/-8 years), Group 2 had 142 patients (mean age 60+/-9 years) and Group 3 had 141 patients (mean age 61+/-8 years). The hfPWV and baPWV increased significantly along with the hsCRP level. Group 1, Group 2 and Group 3 demonstrated hfPWV and baPWV of 965+/-199 and 1438+/-246, 975+/-174 and 1487+/-258 and 1043+/-215 and 1566+/-252 cm/s, respectively (p<0.01). The hfPWV also showed a strong correlation with baPWV (r=0.698, p<0.001). The hsCRP level was independently associated with arterial stiffness (hfPWV: R(2)=0.273, p<0.001; baPWV: R(2)=0.284, p=0.001) after controlling for age, body mass index, systolic blood pressure (BP), heart rate, gender, HDL-cholesterol, triglyceride, glucose level and medications. In conclusion, hsCRP was associated with arterial stiffness, independent of age, systolic BP, gender, heart rate, glucose, lipid profiles and medications in treated hypertension. Therefore, hsCRP could be a useful marker of arterial stiffness in treated hypertension patients and a possible target for arterial inflammation in hypertension.

Causes and consequences of increased arterial stiffness in chronic kidney disease patients

Cardiovascular (CV) morbidity and mortality is greatly enhanced in patients with chronic kidney disease, compared to the non-renal population. One key element of this high CV burden appears to be arterial stiffness, as an expression of premature vascular aging. Increased arterial stiffness in renal patients may be a consequence of vascular calcification, chronic volume overload, inflammation, endothelial dysfunction, oxidative stress and several other factors. The authors review briefly the main pathophysiological mechanisms leading to reduced arterial compliance. Increased arterial stiffness has significant clinical consequences: isolated systolic hypertension, left ventricular hypertrophy (and failure), and reduced myocardial perfusion. Better knowledge of the mechanisms of arterial functional and morphologic alteration may help in developing more refined therapeutic strategies aimed to reduce the high CV burden in chronic kidney disease. The potential therapeutic interventions - mainly the use of certain antihypertensive drugs and reduction of vascular calcification - are finally discussed.

Vascular stiffness in familial hypercholesterolaemia is associated with C-reactive protein and cholesterol burden

BACKGROUND

Familial hypercholesterolaemia (FH) is characterized by very high serum cholesterol and premature coronary atherosclerosis. Arterial stiffness and atherosclerosis are two major underlying pathophysiologies of arterial disease that are predictive of future cardiovascular events. The aims of this study were to quantify atherosclerosis and arterial stiffness and to evaluate their relationship with high sensitive C-reactive protein (hs-CRP) and the level of exposure to high serum cholesterol in FH patients.

MATERIALS AND METHODS

We measured traditional risk factors, hs-CRP, intima-media thickness (IMT) of carotid artery, and brachial-ankle pulse wave velocity (baPWV) in 35 heterozygous FH subjects and 17 healthy control subjects. Cholesterol-year score (CYS) was calculated to estimate the lifetime cholesterol burden in FH subjects.

RESULTS

FH subjects had significantly elevated total cholesterol, low-density lipoprotein cholesterol, and carotid IMT compared with those without mutations. Among FH patients, the baPWV and carotid IMT were higher in cases with high cholesterol burden than those without. Similarly, the baPWV and carotid IMT were also higher in cases with elevated hs-CRP (> 1 mg L(-1)) than those without. Multiple linear regression analysis demonstrated CYS and hs-CRP were significant independent predictors of baPWV and IMT in FH patients.

CONCLUSIONS

Both high cholesterol burden and vascular inflammation are not only associated with atherosclerosis, but also contribute to the development of arterial stiffness in FH patients. Early detection of hypercholesterolaemia in FH patients is warranted to prevent the untoward pathophysiologies.

Relationship between C-reactive protein levels and regional left ventricular function in asymptomatic individuals: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVES

This study sought to investigate the relationship between C-reactive protein (CRP) and regional left ventricular (LV) function in asymptomatic individuals without a history of cardiovascular disease.

BACKGROUND

C-reactive protein is associated with an increased risk for developing cardiovascular disease. However, the relationship between CRP and subclinical LV dysfunction has not been evaluated in asymptomatic individuals.

METHODS

Regional myocardial function was analyzed as peak systolic circumferential shortening strain (Ecc) using the harmonic-phase method by tagged magnetic resonance imaging in 1,164 individuals without symptomatic cardiovascular disease from the MESA (Multi-Ethnic Study of Atherosclerosis) trial (age 66.4 +/- 9.6 years old). Regions were defined by coronary territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). The relationship between log-CRP concentration and Ecc was studied by multivariable linear regression after adjustment for demographic characteristics, risk factors, and therapy (including hormone replacement therapy).

RESULTS

For each region, associations differed by gender with no association of CRP and regional LV function among women. In men, after adjustment, higher log-CRP was significantly associated with lower (absolute) Ecc in the LAD and RCA regions (regression coefficient 0.37 per unit higher log-CRP [95% confidence interval [CI] 0.08 to 0.65] and 0.31 [95% CI 0.02 to 0.59], respectively) and peak systolic Ecc overall (regression coefficient 0.32 [95% CI 0.05 to 0.58]). In the LCX region, the association was weaker (p = 0.06).

CONCLUSIONS

Among individuals without evident heart failure or other cardiovascular disorders, higher CRP was associated with lower systolic myocardial function in all regions in men but not in women. These findings support the role of inflammation and atherosclerosis in incipient myocardial dysfunction. (Multi-Ethnic Study of Atherosclerosis; http://clinicaltrials.gov/ct/show/NCT00005487).

The carotid-femoral (aortic) pulse wave velocity as a marker of arterial stiffness in familial Mediterranean fever

AIM

The purpose of the present study was to test the hypothesis that chronic inflammation impairs vascular function and leads to an arterial pulse wave velocity (PWV) increase in patients with familial Mediterranean fever (FMF).

PATIENTS AND METHODS

Twenty-three patients (17 women) with FMF, and 23 age- and sex-matched controls were recruited. Aortic PWV was determined by using an automatic device (Complior Colson, Createch Industrie, France) that allowed on-line pulse wave recording and automatic calculation of the PWV.

RESULTS

The PWV was slightly higher in patients with FMF than in control subjects (P=0.05). A significant correlation between PWV and age (P<0.001, r=0.67), body mass index (P<0.001, r=0.52) and leukocytes (P<0.001, r=0.66) was found in both groups combined and also in patients with FMF (P<0.001, r=0.73; P=0.01, r=0.52; P<0.001, r=0.69, respectively).

CONCLUSION

The PWV was slightly higher in patients with FMF compared with control subjects. Colchicine, an anti-inflammatory drug treatment, may have reduced the expected increased level of PWV in FMF patients. PWV is influenced by age, body mass index and leukocytes.

Arterial wave reflections and mortality in haemodialysis patients--only relevant in elderly, cardiovascularly compromised?

BACKGROUND

Chronic kidney disease (CKD) patients have a 3-30-fold increased risk of death compared with the general population. This mortality difference is even more pronounced in younger subjects. Two markers of aortic stiffness--aortic pulse wave velocity (PWV) and augmentation index (AIx)--have been prospectively related to all-cause and cardiovascular (CV) mortality in end-stage renal disease (ESRD) populations. The aims of our study were first, to confirm the important deleterious effect of arterial stiffness in uraemia and second, to assess the impact on survival of increased AIx in a relatively young non-diabetic dialysis population, with minimal CV disease.

METHODS

Ninety-two patients (mean age 42.6 +/- 11.2 years) were included in the study and followed for a period of 61 +/- 25 months. None of the patients had diabetes mellitus, and only 3.3% had prior history of CV disease. AIx was determined by applantation tonometry using a SphygmoCor device (AtCor, PWV Inc., Westmead, Sydney, Australia).

RESULTS

Mean AIx in our study population was 19.9 +/- 13.7%; other significant haemodynamic parameters were: systolic blood pressure (SBP) 129 +/- 24 mmHg, pulse pressure 35.3 +/- 17.5 mmHg with 27.2% of the study population receiving angiotensin-converting enzyme inhibitors (ACE-I). On univariate analysis, in our group AIx correlated with: body weight (P < 0.001), radial SBP (P < 0.001) and haemoglobin levels (P < 0.05). There was no correlation between AIx and any of the echocardiographic parameters. In the stepwise multiple regression analysis, the only independent predictors for AIx were weight (P < 0.001), SBP (P < 0.001) and haemoglobin (P < 0.05) with the model explaining 33% of the AIx variability (adjusted R(2) = 0.33). During the follow-up period, 15 deaths were recorded. In the Cox analysis (P = 0.014; chi square 20.7 for the model) the only independent predictors for all-cause mortality were age (P = 0.001), left ventricular mass index (P = 0.032) and ACE-I therapy (P = 0.039) while AIx did not reach statistical significance. There was no difference in patients' survival when divided by AIx tertiles, assessed by the log rank test (P = 0.78).

CONCLUSION

Our results fail to support the notion that an increased effect of wave reflections on central arteries is a strong and independent predictor of mortality in all ESRD patients on haemodialysis. The effect of arterial wave reflections might be in fact dependent on patient age and concurrent comorbidity status.

Increased pulse wave velocity is associated with low creatinine clearance and proteinuria in a screened cohort

BACKGROUND

Chronic kidney disease (CKD) is a risk factor for future cardiovascular disease. Although pulse wave velocity (PWV), which reflects arterial stiffness, was increased in subjects with CKD, little is known regarding whether renal function is associated with PWV in a low-risk population and whether proteinuria and decreased renal function synergistically affect PWV.

METHODS

Subjects are 3,387 persons (mean age, 52 years) who attended a health checkup program in Okinawa, Japan. We measured brachial-ankle PWV (baPWV) by using an automatic oscillometric method. Proteinuria was semiquantified by using the dipstick method. Creatinine clearance (CCr) was estimated by using the Cockcroft-Gault formula.

RESULTS

baPWV was accelerated with increases in age, systolic blood pressure, fasting glucose level, and total cholesterol level; male sex; presence of proteinuria; and decrease in CCr. All these factors independently predicted baPWV in multiple regression analysis. When subjects were divided into 6 groups according to CCr of 90 or greater, 60 to 89, or 30 to 59 mL/min (> or =1.50, 1.00 to 1.48, or 0.50 to 0.98 mL/s) and the absence or presence of proteinuria, baPWV, after adjustment for age, sex, and systolic blood pressure, increased in a stepwise fashion corresponding to decreases in CCr regardless of proteinuria, with the relationship exaggerated in the presence of proteinuria.

CONCLUSION

Arterial stiffness increases with a decrease in renal function or with proteinuria independently of other risk factors.

Aortic stiffness in patients undergoing hemodialysis is positively related to antigen presenting cell-dependent T-lymphocyte reactivity

BACKGROUND

Aortic stiffness is increased in patients undergoing hemodialysis (HD), and it is associated with an increased cardiovascular mortality. Among others, aortic stiffness has been correlated with serum markers of inflammation, indicating a role of the immune system in its pathogenesis. The aim of this study was to evaluate the impact of antigen-presenting cell-dependent T-lymphocyte reactivity on aortic stiffness in HD patients.

PATIENTS AND METHODS

Twenty patients were enrolled in the study. Exclusion criteria were medications or conditions, other than HD, that are known to influence the immune response or aortic stiffness. Antigen-presenting cell-dependent T-lymphocyte reactivity was assessed by cell proliferation of peripheral blood mononuclear cells cultured with or without stimulation with Staphylococcal enterotoxin B (SEB). Cell proliferation was estimated by immunoenzymatic measurement of bromodeoxyuridine uptake. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (PWV) measurement.

RESULTS

Linear regression analysis revealed a strong positive relation between carotid-femoral PWV and antigen-presenting cell-dependent T-lymphocyte reactivity, when SEB at concentrations of 1 ng/mL or 10 ng/mL was used as stimulant.

CONCLUSION

The present study confirms that aortic stiffness in HD patients is positively related to antigen-presenting cell-dependent T-lymphocyte reactivity. The greater the ability of the immune system to react to a monocyte-dependent stimulant and, consequently, to provoke an inflammatory response, the greater the stiffness of the aorta. This is in agreement with the observation that aortic stiffness in HD patients is positively related to various serum inflammation markers.

Study on the relationship of serum fetuin-A concentration with aortic stiffness in patients on dialysis

BACKGROUND

An increase in aortic stiffness, as reflected by an increase in pulse wave velocity (PWV) or aortic augmentation index (AI) is an important predictor of cardiovascular mortality in dialysis patients. Dysregulation of calcification inhibitors, such as fetuin-A, is involved in vascular pathology in dialysis patients and fetuin-A is inversely related to mortality in dialysis patients. In this study, the relation between serum fetuin-A concentration and parameters of aortic stiffness was investigated in patients with end-stage renal disease.

METHODS

In a cross-sectional study we included 131 dialysis patients, aged 62+/-14 years (33 on peritoneal dialysis and 98 on haemodialysis), and 41 controls, aged 60+/-8 years. Time-averaged pre-dialysis values of serum albumin, Ca, P and intact parathyroid hormone were included in multiregression analysis, as were high-sensitivity C-reactive protein (hsCRP), fetuin-A, age, mean arterial pressure (MAP) and dialysis modality. PWV and AI were measured with the SphygmoCor device.

RESULTS

Mean fetuin-A concentration in dialysis patients (0.63+/-0.16 g/l) did not differ from controls (0.63+/-0.11 g/l). Median hsCRP levels in dialysis patients were higher compared with controls (4.0 vs 1.9 mg/l; P<0.0001). PWV but not AI was higher in dialysis patients than in controls (9.9 vs 7.9 m/s; P<0.0001). In univariate analysis in dialysis patients, fetuin-A levels were inversely related to both PWV (r = - 0.25, P = 0.007) and AI (r = - 0.26, P = 0.006), respectively. However, after correction for age, gender, MAP and diabetes mellitus, this relation lost statistical significance.

CONCLUSIONS

In a dialysis population with a relatively low level of inflammatory activity, the soluble calcification inhibitor fetuin-A could not be identified as an independent predictor of aortic stiffness as measured with PWV and AI.

Low doses of losartan and trandolapril improve arterial stiffness in hemodialysis patients

BACKGROUND

Hemodialysis patients have uremic dyslipidemia, represented by elevated serum intermediate-density lipoprotein cholesterol (IDL-C) levels, and an increased cardiovascular mortality rate. This study was performed to determine the low-dose effects of the angiotensin II receptor blocker losartan and the angiotensin-converting enzyme inhibitor trandolapril on pulse wave velocity (PWV), which predicts cardiovascular morbidity and mortality in hemodialysis patients.

METHODS

Serum lipid levels and PWV were monitored for 12 months in 64 hemodialysis patients who were administered low doses of losartan or trandolapril or a placebo.

RESULTS

At the start of the study, there were no differences in patient characteristics among the 3 groups. PWV tended to increase in the placebo group during the 12-month study period, but decreased significantly in the losartan and trandolapril groups, and decreases in PWV were similar in the losartan and trandolapril groups. There were no changes in blood pressure, hematocrit, erythropoietin dose, ankle-brachial index, serum lipid levels, serum 8-isoprostane levels, or serum C-reactive protein levels during the 12-month study period, but there was an increase in serum triglyceride levels in the losartan group and a decrease in serum IDL-C levels in the losartan and trandolapril groups.

CONCLUSION

In hemodialysis patients, trandolapril is as effective as losartan in decreasing PWV independent of its depressor effect and in suppressing elevated IDL-C levels. Long-term blockade of the renin-angiotensin system may have a beneficial effect on the acceleration of atherosclerosis and uremic dyslipidemia.