Association Between Pretransplant Dialysis Modality and Kidney Transplant Outcomes: A Systematic Review and Meta-analysis

IMPORTANCE

The benefits and disadvantages of different pretransplant dialysis modalities and their posttransplant outcomes remain unclear in contemporary kidney transplant care.

OBJECTIVE

To summarize the available evidence of the association of different pretransplant dialysis modalities, including hemodialysis and peritoneal dialysis (PD), with posttransplant outcomes.

DATA SOURCES

MEDLINE, Embase, PubMed, Cochrane Library, Scopus, CINAHL, and gray literature were searched from inception to March 18, 2022 (updated to April 1, 2022), for relevant studies and with no language restrictions.

STUDY SELECTION

Randomized clinical trials and nonrandomized observational (case-control and cohort) studies that investigated the association between pretransplant dialysis modality and posttransplant outcomes regardless of age or donor sources (living or deceased) were abstracted independently by 2 reviewers.

DATA EXTRACTION AND SYNTHESIS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology reporting guidelines, 2 reviewers independently extracted relevant information using a standardized approach. Random-effects meta-analysis was used to estimate pooled adjusted hazard ratio (HR) or odds ratio and 95% CI.

MAIN OUTCOMES AND MEASURES

Primary outcomes included all-cause mortality, overall graft failure, death-censored graft failure, and delayed graft function. Secondary outcomes included acute rejection, graft vessel thrombosis, oliguria, de novo heart failure, and new-onset diabetes after transplant.

RESULTS

The study analyzed 26 nonrandomized studies (1 case-control and 25 cohort), including 269 715 patients (mean recipient age range, 14.5-67.0 years; reported proportions of female individuals, 29.4%-66.9%) whose outcomes associated with pretransplant hemodialysis vs pretransplant PD were compared. No significant difference, with very low certainty of evidence, was observed between pretransplant PD and all-cause mortality (13 studies; n = 221 815; HR, 0.92 [95% CI, 0.84-1.01]; P = .08) as well as death-censored graft failure (5 studies; n = 96 439; HR, 0.98 [95% CI, 0.85-1.14]; P = .81). However, pretransplant PD was associated with a lower risk for overall graft failure (10 studies; n = 209 287; HR, 0.96 [95% CI, 0.92-0.99]; P = .02; very low certainty of evidence) and delayed graft function (6 studies; n = 47 118; odds ratio, 0.73 [95% CI, 0.70-0.76]; P < .001; low certainty of evidence). Secondary outcomes were inconclusive due to few studies with available data.

CONCLUSIONS AND RELEVANCE

Results of the study suggest that pretransplant PD is a preferred dialysis modality option during the transition to kidney transplant. Future studies are warranted to address shared decision-making between health care professionals, patients, and caregivers as well as patient preferences.

Yellow Yeast Rice Prepared Using Aspergillus terreus DSMK01 Lowers Cholesterol Levels by Stimulating Bile Salt Export Pump in Subjects with Mild-to-Moderate Hypercholesterolemia: A Randomized Controlled Trial

SCOPE

Aspergillus terreus is an industrial microorganism used in the brewing and sauce industries. It produces monacolin K, a natural statin. The study conducted an 8-week randomized controlled trial with hypercholesterolemic subjects to examine the hypocholesterolemic effects and mechanisms of supplementation with yellow yeast rice (YYR) prepared by growing Aspergillus fungi on steamed rice.

METHODS AND RESULTS

YYR supplementation markedly reduced total cholesterol, LDL, and apolipoprotein B100 levels in plasma compared with the placebo. In addition, YYR induced a significantly increased ATP binding cassette subfamily B member 11 (ABCB11) gene expression compared with the placebo, indicating the role of YYR in lowering intrahepatic cholesterol availability by stimulating the bile salt export pump. Upregulation of LDL receptor (LDLR) and 3-methylglutaryl-CoA reductase (HMGCR) gene expressions provided additional evidence to support the role of YYR in reducing hepatic cholesterol availability. Plasma metabolomic profiling revealed the possibility of diminishing bile acid absorption. Finally, Spearman rank analysis showed correlations of plasma cholesterol profiles with HMGCR and LDLR gene expressions (negative) and plasma bile acids (positive). Plasma bile acids also correlated with ABCB11 (negative) and LDLR (positive) gene expressions.

CONCLUSION

These findings suggest that daily YYR supplementation exerted hypocholesterolemic effects in mild-to-moderate hypercholesterolemic subjects by reducing intrahepatic cholesterol availability through stimulating bile salt export pumps and inhibiting cholesterol biosynthesis.

A comparison of the risk of congestive heart failure-related hospitalizations in patients receiving hemodialysis and peritoneal dialysis - A retrospective propensity score-matched study

Introduction

Congestive heart failure (CHF) is associated with high mortality and a heavy financial and healthcare burden in the dialysis population. Determining which dialysis modality is associated with a higher risk of developing CHF might facilitate clinical decision making and surveillance programs in the dialysis population.

Methods

Using the Taiwan National Health Insurance Database, we recruited all incident dialysis patients during the period from January 1, 1998 to December 31, 2010. The propensity score matching method was applied to establish the matched hemodialysis (HD) and peritoneal dialysis (PD) cohort. Incidence rates and cumulative incidence rates of CHF-related hospitalization were first compared for the HD and PD patients. Multivariable subdistribution hazards models were then constructed to control for potential confounders.

Results

Among a total of 65,899 enrolled dialysis patients, 4,754 matched pairs of HD and PD patients were identified. The incidence rates of CHF in the matched HD and PD patients were 25.98 and 19.71 per 1000 patient-years, respectively (P = 0.001). The cumulative incidence rate of CHF was also higher in the matched HD patients (0.16, 95% confidence interval (CI)(0.12–0.21)] than in the corresponding PD patients (0.09, 95% CI [0.08–0.11])(P<0.0001). HD was consistently associated with an increased subdistribution hazard ratio (HR) of CHF compared with PD in the matched cohort (HR: 1.45, 95% CI [1.23–1.7]). Similar phenomenons were observed in either the subgroup analysis stratified by selected confounders or in the HD and PD group without matching.

Conclusions

HD is associated with a higher risk of developing CHF-related hospitalization than PD. The surveillance program for CHF should differ in patients receiving different dialysis modalities.

The assessment of P-wave dispersion and myocardial repolarization parameters in patients with chronic kidney disease

Objective: The risks of sudden death and cardiac arrhythmia are increased in patients with chronic kidney disease (CKD). Here, we aimed to evaluate the indicators of arrhythmias, such as p-wave dispersion (P-WD), QTc dispersion, Tp-e and Tp-e/QT ratio in patients with CKD stages 3–5 on no renal replacement therapy (RRT).

Material and methods: One-hundred and thirty three patients with CKD stages 3–5 and 32 healthy controls were enrolled into the study. No patients received RRT. QTc dispersion, P-WD and Tp-e interval were measured using electrocardiogram and Tp-e/QT ratio was also calculated.

Results: Mean age rates were found similar in patients and controls (60.8 ± 14.2 and 61 ± 12.9 y, p = .937, respectively). Compared patients with controls, P-WD (45.85 ± 12.42 vs. 21.17 ± 6.6 msec, p < .001), QTc-min (366.99 ± 42.31 vs. 387.15 ± 20.5 msec, p < .001), QTc dispersion (71.13 ± 27.95 vs. 41.25 ± 14.55 msec, p < .001), Tp-e maximum (81.04 ± 10.34 vs. 75.49 ± 10.9 msec, p < .001), Tp-e minimum (62.25 ± 7.58 vs. 54.8 ± 6.72 msec, p < .001) and Tp-e/QTc ratio (0.19 ± 0.02 vs. 0.18 ± 0.01, p = .001) were found to be different. QTc-max and Tp-e interval were found to be similar in both groups.

Conclusion: P-WD and QTc dispersion, Tp-e interval and Tp-e/QTc ratio were found to be increased in with CKD stages 3–5 on no RRT.

Serial versus single troponin measurements for the prediction of cardiovascular events and mortality in stable chronic haemodialysis patients

AIM

This study aims to describe the variability of pre-dialysis troponin values in stable haemodialysis patients and compare the performance of single versus fluctuating or persistently elevated troponins in predicting a composite of mortality and cardiac arrest, myocardial infarction or stroke.

METHODS

A total of 128 stable ambulatory chronic haemodialysis patients were enrolled. Pre-dialysis troponin I was measured for three consecutive months. The patients were followed for 1 year. A troponin elevation (>0.06 μg/L) was considered high risk, and patients were classified into three risk groups: (i) patients who had normal troponin levels on all three measurements; (ii) patients with at least one elevated and one normal troponin value; and (iii) patients with elevated troponin values on all measurements.

RESULTS

A total of 81 patients had all three troponin values in the normal range; 29 had fluctuating values; 18 had all three values elevated. Twenty-seven deaths or composite events were observed: eight in the first risk group, 10 in the second and nine in the third. Persistently elevated and fluctuating troponin values were associated with higher mortality and cardiovascular event rate. Serial troponin measurement had a higher sensitivity for the composite outcome than single troponin measurement when either fluctuating or persistently elevated values were considered to confer high risk.

CONCLUSION

Most haemodialysis patients do not have elevated troponin levels at baseline. Troponin levels that remain elevated or fluctuate are associated with worse outcomes. A serial troponin measurement strategy is associated with better sensitivity and higher negative predictive value compared with single troponin measurement.

Factors influencing P terminal force in lead V1 of the ECG in hemodialysis patients

INTRODUCTION

Atrial fibrillation (AF) is a highly prevalent arrhythmia in hemodialysis (HD) patients, and an HD session may be a trigger for AF episodes. An abnormal P-terminal force in lead V1 (PTFV1) may predict new-onset AF in HD patients. The aim of the study was to assess the influence of the HD process on PTFV1 and to evaluate possible factors influencing PTFV1 in a group of selected HD patients.

MATERIAL AND METHODS

One hundred and fifty-three selected HD patients entered the study. Blood chemistry, electrocardiography, and impedance cardiography were evaluated before and after HD. Echocardiography was performed on the morning after dialysis. Abnormal PTFV1 was defined as PTFV1 > 40 mm × ms.

RESULTS

Abnormal PTFV1 was found in 35.3% of patients before dialysis and in 48.4% of patients after dialysis. The results of multiple regression analysis revealed that the independent predictors of pre-dialysis abnormal PTFV1 were: left atrial volume index (p = 0.002), left ventricular mass index (p = 0.014), and pre-dialysis thoracic fluid content (p = 0.021) values. The independent predictors of HD-induced abnormal PTFV1 values were larger differences between pre-dialysis and post-dialysis values of serum potassium (p < 0.001) and mean arterial pressure (p = 0.008).

CONCLUSIONS

Abnormal PTFV1 is prevalent in HD patients. The HD process adversely affects PTFV1 values. Pre-dialysis abnormal PTFV1 is mainly associated with structural heart abnormalities and hydration status. HD-induced abnormal PTFV1 is associated predominantly with serum potassium changes as well as HD-induced hypotension. Our results suggest possible risk factors for AF; however, their clinical significance needs to be confirmed in follow-up studies.

Using controlled attenuation parameter combined with ultrasound to survey non-alcoholic fatty liver disease in hemodialysis patients: A prospective cohort study

BACKGROUND AND AIMS

Controlled attenuation parameter (CAP) is a non-invasive method for measuring hepatic steatosis (HS). Non-alcoholic fatty liver disease (NAFLD) is closely related to cardiovascular diseases (CVDs). CVDs are the leading cause of morbidity and mortality in hemodialysis patients. The aim of this study was to investigate the prevalence of NAFLD in hemodialysis patients.

METHOD

We prospectively enrolled patients undergoing chronic hemodialysis, as well as patients with normal renal function who served as controls. The control group patients were referred by an endocrinologist to be tested for NAFLD; most of these patients had diabetes, hypertension, or dyslipidemia. We excluded those with excess alcohol intake, use of drugs known to induce HS, chronic viral hepatitis, or CAP failure. CAP ≥ 238 dB/m was used as a cutoff suggesting HS. An increased liver kidney contrast, as defined by ultrasound, was used to make the diagnosis of HS.

RESULTS

Three hundred and forty-three hemodialysis patients and 252 control group patients were enrolled. Among the hemodialysis patients, 192 (56.0%) had CAP- or ultrasound-identified HS compared with 91 (26.5%) who only had ultrasound-identified HS (P<0.001). Among the control group patients, 212 (84.1%) had CAP- or ultrasound-identified HS compared with 180 (71.4%) who only had ultrasound-identified HS (P<0.001).

CONCLUSIONS

The prevalence of NAFLD in the hemodialysis patients was 56%. The number of diagnoses of NAFLD made by using CAP combined with ultrasound was more than 2 times the number made with ultrasound alone in the hemodialysis patients. Therefore, we suggest the use of CAP combined with ultrasound to screen for NAFLD in hemodialysis patients.

Acute Haemodialysis-induced Changes in Tissue Doppler Echocardiography Parameters

BACKGROUND

Tissue Doppler imaging (TDI) is a method that determines the tissue motion and velocity within the myocardium.

AIMS

To characterize acute haemodialysis (HD)-induced changes in TDI-derived indices for patients that have end-stage renal disease (ESRD).

STUDY DESIGN

Cross sectional study.

METHODS

Conventional echocardiography and TDI methods were applied to study ESRD patients (n=58) before and after HD. Pulmonary venous flow, mitral inflow, and TDI signals of the lateral and septal mitral annulus were examined for the determination of altered left-ventricular diastolic filling parameters. Flow velocities from early- (E) and late-atrial (A) peak transmitral; peak pulmonary vein systolic (S) and diastolic (D); and myocardial peak systolic (Sm) and peak early (Em) and late (Am) diastolic mitral annular velocities were also assessed for changes.

RESULTS

Transmitral E and A velocities and the E/A ratio decreased significantly after HD (p<0.001). Pulmonary vein S (p<0.001) and D (p<0.001) velocities decreased, and S/D ratios increased significantly (p=0.027). HD led to a reduction in septal Em (p<0.001), lateral Em (p=0.006), and Am (p<0.001) velocities. Contrary to the decreases in Em and Am, the Em/Am ratio remained unchanged.

CONCLUSION

A single HD session was associated with an acute deterioration in the diastolic parameters. Since the Em/Am ratio remained unchanged, we conclude that this index is a relatively load-independent measure of diastolic function in HD patients.

Chronic kidney disease and nonalcoholic Fatty liver disease-is there a link?

Research in recent years has led to the recognition of the importance of nonalcoholic fatty liver disease (NAFLD) and its relationship to the metabolic syndrome (MS). This has led to a growing interest in the potential prognostic value of NAFLD for adverse cardiovascular disease (CVD) outcome. On the other hand, searching for new risk factors for chronic kidney disease (CKD) development and progression is very important. Growing evidence suggests that the MS is an important factor in the pathogenesis of CKD. The best confirmation of this pathogenic link is hypertensive and diabetic nephropathy as the main causes of CKD. Furthermore, the possible link between NAFLD and CKD has also attracted research interest and recent data suggest an association between these two conditions. These findings have fuelled concerns that NAFLD may be a new and added risk factor for the development and progression of CKD. NAFLD and CKD share some important cardiometabolic risk factors and possible common pathophysiological mechanisms, and both are linked to an increased risk of incident CVD events. Therefore, common factors underlying the pathogenesis of NAFLD and CKD may be insulin resistance, oxidative stress, activation of rennin-angiotensin system, and inappropriate secretion of inflammatory cytokines by steatotic and inflamed liver.

Nonalcoholic fatty liver disease (NAFLD): a new risk factor for adverse cardiovascular events in dialysis patients

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in Western countries. Today it is believed that NAFLD is a hepatic manifestation of metabolic syndrome, and thus it is closely related to the cardiovascular morbidity and mortality. Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in patients with end-stage-renal disease (ESRD). NAFLD and ESRD share some important cardiometabolic risk factors and possible common pathophyisiological mechanisms, and are linked to an increased risk of incident CVD events. We hypothesize that the coexistence of these two conditions could lead to much faster progress of the aterogenic process. Furthermore, patients with ESRD who suffer from NAFLD have a much higher risk for the development of adverse CVD events. Given the high prevalence of NAFLD, and its tight association with other manifestations of the metabolic syndrome and thus cardiovascular complications, it is important to recognize and aggressively treat this condition in ESRD patients. To evaluate this hypothesis, we propose the use of non-invasive methods such as transient elastography (TE) (Fibroscan-CAP) for the detection and quantification of liver steatosis and fibrosis, as well as an abdominal ultrasound for detecting liver steatosis. We focus on their correlation with carotid intima-media thickness (IMT) and plaque as surrogate measures of increased cardiovascular risk in HD patients in order to investigate the association of NAFLD and increase risk of adverse CVD events. This evaluation will prove useful in assessing the risk in HD patients with NAFLD for increase CVD mortality.

Safety and efficacy of statins in patients with end-stage renal disease

OBJECTIVE

To review statins in the prevention of cardiovascular disease (CVD) events and their associated safety in patients with end-stage renal disease (ESRD).

DATA SOURCES

Peer-reviewed clinical trials, review articles, and treatment guidelines were identified from MEDLINE (1966-July 2013) using the following search terms: end stage renal disease, statin, HMG-CoA (hydroxymethylglutaryl-coenzyme A) reductase inhibitor, chronic kidney disease, cardiovascular outcomes, and cardiovascular disease. Results were limited to human trials published in English. Citations from articles were reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

Only clinical trials evaluating cardiovascular end points of statins used in patients with ESRD were included.

DATA SYNTHESIS

In patients with ESRD, CVD is the leading cause of death. Statin therapy has been evaluated in 3 clinical trials in patients with ESRD. The 4D and AURORA trials failed to show a benefit with statin therapy, and the SHARP trial, although positive, also included patients with earlier stages of chronic kidney disease. Despite the lack of efficacy, statin therapy was well tolerated. The cause of cardiovascular death in this patient population may not be a result of atherosclerotic events and possibly dependent on the type of renal replacement therapy. For patients on hemodialysis, lipid profiles may not be amenable to statin therapy.

CONCLUSIONS

Statin therapy has failed to significantly alter the course of CVD events in patients with ESRD. Evidence supports avoiding the routine use of statins in this patient population and instead reserving them for patients with elevated cholesterol levels or those with recent CVD events.

Ischemic heart disease in patients undergoing dialysis

Cardiovascular disease is the most common cause of death in patients with end-stage renal disease (ESRD) who are undergoing chronic dialysis. Diabetes and hypertension, the 2 leading causes of ESRD, contribute to the pathogenesis of ischemic heart disease (IHD) in these patients, as do other traditional risk factors (eg, dyslipidemias, smoking, and sedentary lifestyle). However, patients with ESRD are subject to several unique risk factors that contribute to the development and progression of IHD. Chronic volume overload and anemia, leading to left ventricular hypertrophy, and deranged calcium-phosphate metabolism with vascular and coronary calcification, contribute to the pathogenesis of IHD. Other risk factors that have been implicated include oxidative stress, homocysteine, and myocardial stunning while undergoing dialysis treatment. Additional risk factors include erythropoietin use for treating anemia, as well as use of calcium-based phosphate binders. The complex pathogenesis of IHD in such patients poses unique challenges to its management. Serological biomarkers and sophisticated imaging techniques are being developed to better delineate the pathological process and enhance disease detection. A combination of medical and surgical approaches is necessary to treat IHD. In this article, we discuss the pathogenesis and management of IHD.

Biomarkers in hemodialysis patients

Patients with chronic kidney disease (CKD) are, compared to the general population, at higher risk of cardiovascular disease (CVD), including sudden death, coronary artery disease (CAD), congestive heart failure (HF), stroke, and peripheral artery disease. The presence of CVD is independently associated with kidney function decline. Renal insufficiency is a strong and independent predictor of mortality in patients with different CKD stages. The interplay of traditional and nontraditional risk factors is complex such that risk factor profiles are different in CKD patients. Seemingly, paradoxical associations between traditional risk factors and cardiovascular outcome complicate efforts to identify real cardiovascular etiology in these patients. Additional tools are often required to aid clinical assessment of cardiovascular risk. Recently, a number of cardiovascular biomarkers were identified as predictors of outcome in CVD. These may be used to guide early diagnosis and therapy for CVD or may predict outcome in CKD. This review focuses on the potential diagnostic and prognostic use of some important new biomarkers including brain natriuretic peptide (BNP), cardiac troponins (cTns), inflammatory markers, adhesion molecules, and asymmetric dimethylarginine (ADMA) in CKD as well as those patients with end-stage renal failure.

Statins and kidney disease: is the study of heart and renal protection at the cutting edge of evidence?

PURPOSE OF REVIEW

Dyslipidaemias are noted in all stages of chronic kidney disease (CKD). Currently most evidence for their treatment comes from secondary retrospective analyses of patient subgroups with CKD recruited into clinical trials powered of hypertensive and dyslipideamic cohorts powered for cardiovascular endpoints.These analyses suggest a number of different beneficial effects of statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) on renal, cardiovascular and mortality outcomes. However, there is disagreement on the impact of interventions at different CKD stages, and on treatment targets.

RECENT FINDINGS

The Study of Heart and Renal Protection (SHARP) trial published in June 2011 was the first trial specifically powered to investigate atherosclerotic outcomes in CKD patients. It found a 17% overall reduction in major adverse cardiac events in the statin-treated group compared with placebo, yet no effect on any renal outcomes of proteinuria and progressive decline of glomerular filtration rate. Furthermore, the Swedish Web-system for Enhancement and Development of Evidencebased care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) investigators provided further important observational data on the beneficial effect of statins in CKD stages I-IV.

SUMMARY

The evidence that statins have a cardiovascular and mortality benefit in CKD stages I-IV has been reinforced by SHARP, which also definitively shows that there are no special safety concerns for their administration in CKD. However, the utility of the use of statins in patients on dialysis is far from clear, at least in our opinion. The effect of statins on renal outcomes is unconvincing and the evidence does not presently support their use for these indications alone.

Clinical Use and Measurement of Cardiac Troponin (cTn)

Cardiac troponins are cardio-specific and are widely used for the early diagnosis and triage of patients with acute coronary syndromes in conjunction with clinical history, electrocardiographic changes and imaging. Troponin is also useful for the prediction of outcomes in acute coronary syndromes, renal failure, sepsis, and critically ill patients. New developments in assay technology, designated as high sensitivity troponins, permit detection of lower levels of troponin in most healthy individuals, earlier diagnosis of myocardial infarction, and prognosis of stable coronary disease in the community.

Early start of dialysis: a critical review

In the US, patients who initiate dialysis "early" (at Modification of Diet in Renal Disease estimated GFR [eGFR]> 10 ml/min per 1.73 m(2)) account for over 50 percent of new dialysis starts. This trend to an early start is based on conventional wisdoms regarding benefits of dialytic clearance, that albumin levels are nutritional markers, and early dialytic therapy is justified to improve nutrition especially in diabetics and that waiting until low levels of eGFR (i.e., <6 ml/min per 1.73 m(2)) may be dangerous. In order to justify early dialysis treatment, the therapy must provide a morbidity, mortality, or quality of life benefit. The current review examines whether early dialysis initiation provides any of these benefits and whether the conventional wisdoms that have promoted this early dialysis trend are valid. Utilizing this information and the results of recent large observational studies and the randomized controlled Initiating Dialysis Early and Late (IDEAL) study, we suggest that dialysis initiation is justified at GFR levels of 5-9 ml/min/1.73 m(2), if accompanied by uremia symptoms or fluid management issues.

Shining D' light on chronic kidney disease: mechanisms that may underpin the cardiovascular benefit of vitamin D

Hypovitaminosis D is a significant health-care burden worldwide, particularly in susceptible populations such as those with chronic kidney disease (CKD). Recent epidemiological studies have identified that both higher serum vitamin D concentrations and use of vitamin D supplements may confer a survival benefit both in terms of all-cause and cardiovascular mortality. There is potential to investigate this inexpensive therapy for the CKD population, which suffers excessive cardiovascular events, although the mechanisms explaining this link have yet to be fully elucidated. This review discusses potential mechanisms identified in the basic science literature that may provide important insights into how vitamin D may orchestrate a change in cardiovascular risk profile through such diverse mechanisms as inflammation, atherogenesis, glucose homeostasis, vascular calcification, renin-angiotensin regulation and alterations in cardiac physiology. Where available, the clinical translation of these concepts to intervention trials in the CKD population will be reviewed.

Abdominal obesity is the most significant metabolic syndrome component predictive of cardiovascular events in chronic hemodialysis patients

BACKGROUND

Five components of metabolic syndrome (MetS) have been identified as predictive of cardiovascular events (CVEs) in the general population: impaired fasting glucose, abdominal obesity, hypertriglyceridemia, hypertension and low high-density lipoprotein cholesterol. Whether MetS and its components are also predictive of CVEs in chronic hemodialysis (HD) patients remains unclear. We therefore investigated the role of MetS and its components in patients on chronic HD.

METHODS

MetS at baseline was diagnosed in 91 HD patients based on the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. During a 3-year period, all hospitalizations, CVEs and deaths were recorded and analyzed using Kaplan-Meier survival analysis and Cox regression.

RESULTS

There were no differences in the number of CVEs, hospitalizations or deaths between patients with and without AHA/NHLBI-defined MetS; however, patients with IDF-defined MetS were found to be at a higher risk for CVEs (P = 0.006). Cox regression analysis showed that, of the MetS components, abdominal obesity was the single most significant predictor of CVEs (hazard ratio 6.25; 95% confidence interval: 1.65-23.6; P = 0.007).

CONCLUSIONS

IDF-defined MetS was more predictive of CVEs than AHA/NHLBI-defined MetS. Of the MetS components, abdominal obesity was the single most significant predictor of CVEs in chronic HD patients.

Plasma apolipoprotein C-III metabolism in patients with chronic kidney disease

Moderate chronic kidney disease (CKD) (defined by an estimated glomerular filtration rate of 30-60 ml/min) is associated with mild hypertriglyceridemia related to delayed catabolism of triglyceride-rich lipoprotein particles. Altered apolipoprotein C-III (apoC-III) metabolism may contribute to dyslipidemia in CKD. To further characterize the dyslipidemia of CKD, we investigated the kinetics of plasma apoC-III in 7 nonobese, nondiabetic, non-nephrotic CKD subjects and 7 age- and sex-matched healthy controls, using deuterated leucine ([5, 5, 5, ²H₃]leucine), gas chromatography-mass spectrometry, and multicompartmental modeling. Compared with controls, CKD subjects had higher concentrations of plasma and VLDL triglycerides and plasma and VLDL apoC-III (P < 0.05). The increased plasma apoC-III concentration was associated with a decreased apoC-III fractional catabolic rate (FCR) (1.21 ± 0.15 vs. 0.74 ± 0.12 pools/day, P = 0.03). There were no differences between apoC-III production rates of controls and those of CKD subjects. In CKD subjects, plasma apoC-III concentration was significantly and negatively correlated with apoC-III FCR (r = -0.749, P = 0.05) but not with apoC-III production rate. Plasma apoC-III concentration was positively correlated with plasma and VLDL triglycerides and VLDL apoB concentrations and negatively correlated with VLDL apoB FCR (P < 0.05 for all). ApoC-III FCR was negatively correlated with plasma and VLDL triglycerides and VLDL apoB concentration and positively correlated with VLDL apoB FCR (P < 0.05 for all). Altered plasma apoC-III metabolism is a feature of dyslipidemia in moderate CKD. Modification of apoC-III catabolism may be an important therapeutic target for reducing cardiovascular disease risk in moderate CKD.

Cardiovascular disease in end-stage renal disease: the challenge of assessing and managing cardiac disease in dialysis patients

Cardiovascular disease (CVD) is the leading cause of mortality in end-stage renal disease (ESRD), approximating a 10- to 20-fold higher risk of death in dialysis patients than in the general population. Despite this, dialysis patients often undergo fewer investigations, receive less invasive procedures, and are prescribed fewer medications compared with age-matched non-ESRD patients. A lack of randomized control trials for evidence-based treatment strategies in this population may explain some of these discrepancies, but there is concern that an attitude of "therapeutic nihilism" may be impacting on the medical care of these patients. In this review, we will explore CVD in the ESRD population. Specifically, we will try to address the following issues in patients with ESRD: (1) mechanisms of CVD, (2) cardiac evaluation and the role of coronary revascularization with percutaneous or coronary artery bypass procedures, and (3) cardiac pharmacotherapy use.