Diagnosis and treatment of hypertension in dialysis patients: a systematic review

In patients with end-stage renal disease (ESRD) undergoing dialysis, hypertension is common but often inadequately controlled. The prevalence of hypertension varies widely among studies because of differences in the definition of hypertension and the methods of used to measure blood pressure (BP), i.e., peri-dialysis or ambulatory BP monitoring (ABPM). Recently, ABPM has become the gold standard for diagnosing hypertension in dialysis patients. Home BP monitoring can also be a good alternative to ABPM, emphasizing BP measurement outside the hemodialysis (HD) unit. One thing for sure is pre- and post-dialysis BP measurements should not be used alone to diagnose and manage hypertension in dialysis patients. The exact target of BP and the relationship between BP and all-cause mortality or cause-specific mortality are unclear in this population. Many observational studies with HD cohorts have almost universally reported a U-shaped or even an L-shaped association between BP and all-cause mortality, but most of these data are based on the BP measured in HD units. Some data with ABPM have shown a linear association between BP and mortality even in HD patients, similar to the general population. Supporting this, the results of meta-analysis have shown a clear benefit of BP reduction in HD patients. Therefore, further research is needed to determine the optimal target BP in the dialysis population, and for now, an individualized approach is appropriate, with particular emphasis on avoiding excessively low BP. Maintaining euvolemia is of paramount importance for BP control in dialysis patients. Patient heterogeneity and the lack of comparative evidence preclude the recommendation of one class of medication over another for all patients. Recently, however, β-blockers could be considered as a first-line therapy in dialysis patients, as they can reduce sympathetic overactivity and left ventricular hypertrophy, which contribute to the high incidence of arrhythmias and sudden cardiac death. Several studies with mineralocorticoid receptor antagonists have also reported promising results in reducing mortality in dialysis patients. However, safety issues such as hyperkalemia or hypotension should be further evaluated before their use.

Magnesium but not nicotinamide prevents vascular calcification in experimental uraemia

BACKGROUND

Optimal phosphate control is an unmet need in chronic kidney disease (CKD). High serum phosphate increases calcification burden and is associated with mortality and cardiovascular disease in CKD. Nicotinamide (NA) alone or in combination with calcium-free phosphate binders might be a strategy to reduce phosphate levels and calcification and thus impact cardiovascular disease in CKD.

METHODS

We studied the effect of NA alone and in combination with magnesium carbonate (MgCO3) as a potential novel treatment strategy. CKD was induced in dilute brown non-agouti/2 mice by subtotal nephrectomy followed by a high-phosphate diet (HP) and 7 weeks of treatment with NA, MgCO3 or their combination. Control mice underwent subtotal nephrectomy and received an HP or underwent sham surgery and received standard chow plus NA.

RESULTS

CKD mice showed increased serum fibroblast growth factor 23 and calcium-phosphate product that was normalized by all treatment regimes. NA alone increased soft tissue and vascular calcification, whereas any treatment with MgCO3 significantly reduced calcification severity in CKD. While MgCO3 supplementation alone resulted in decreased calcification severity, it resulted in increased intestinal expression of the phosphate transporters type II sodium-dependent phosphate transporter 1 (Pit-1). Combined therapy of MgCO3 and NA reduced tissue calcification and normalized expression levels of intestinal phosphate transporter proteins.

CONCLUSIONS

In conclusion, the data indicate that NA increases while MgCO3 reduces ectopic calcification severity. Augmented expression of intestinal phosphate transporters by MgCO3 treatment was abolished by the addition of NA. However, the clinical relevance of the latter remains to be explored. Importantly, the data suggest no benefit of NA regarding treatment of calcification in addition to MgCO3.

Postoperative Ultrasound in Kidney Transplant Recipients: Association Between Intrarenal Resistance Index and Cardiovascular Events

Doppler ultrasound, including intrarenal resistance index (RI) measurement, is a widely used modality to assess kidney transplantation (KTx) vascularization. The aim of this study is to gain insight in the associations between early postoperative RI measurements and cardiovascular events (CVEs), all-cause mortality, and death-censored graft survival.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) and All-Cause and Cardiovascular Mortality in Diverse Hemodialysis Patients

Introduction

The soluble receptor of urokinase plasminogen activator (suPAR) is an innate immunity/inflammation biomarker predicting cardiovascular (CV) and non-CV events in various conditions, including type 2 diabetic patients on dialysis. However, the relationship between suPAR and clinical outcomes in the hemodialysis population at large has not been tested.

Methods

We measured plasma suPAR levels (R&D enzyme-linked immunosorbent assay [ELISA]) in 1038 hemodialysis patients with a follow-up of 2.9 years (interquartile range = 1.7−4.2) who were enrolled in the PROGREDIRE study, a cohort study involving 35 dialysis units in 2 regions in Southern Italy.

Results

suPAR was strongly (P < 0.001) and independently related to female gender (β = −0.160), age (β = 0.216), dialysis vintage (β = 0.264), CV comorbidities (β = 0.105), alkaline phosphatase (β = 0.136), albumin (β = −0.147), and body mass index (BMI; β = 0.174) (all P < 0.006). In fully adjusted analyses, suPAR tertiles predicted the risk of all-cause mortality (third tertile vs. first tertile hazard ratio (HR) = 1.91, 95% confidence interval (CI) = 1.47 – 2.48, P < 0.001), CV mortality (HR = 1.47, 95% CI = 1.03–2.09, P = 0.03), and non-CV mortality (HR = 1.94, 95% CI = 1.28–2.93, P = 0.002); these relationships were not modified by diabetes or other risk factors. suPAR added only modest prognostic risk discrimination and reclassification power for these outcomes to parsimonious models based on simple clinical variables.

Conclusion

In conclusion, suPAR robustly predicted all-cause and both CV and non-CV mortality in a large unselected hemodialysis population. Intervention studies are needed to definitively test the hypothesis that suPAR is causally implicated in clinical outcomes in this population.

Do we still need cross-sectional studies in Nephrology? Yes we do!

Cross-sectional studies represent the second line of evidence (after case reports) in the ladder of evidence aimed at defining disease aetiology. This study design is used to generate hypotheses about the determinants of a given disease but also to investigate the accuracy of diagnostic tests and to assess the burden of a given disease in a population. The intrinsic limitation of cross-sectional studies, when applied to generate aetiological hypotheses, is that both the exposure under investigation and the disease of interest are measured at the same point in time. For this reason, generally the cross-sectional design does not provide definitive proofs about cause-and-effect relationships. An advantage of cross-sectional studies in aetiological and diagnostic research is that they allow researchers to consider many different putative risk factors/diagnostic markers at the same time. For example, in a hypothetical study aimed at generating hypotheses about the risk factors for left ventricular hypertrophy (LVH) in patients with chronic kidney disease, investigators could look at several risk factors as potential determinants of LVH (age, gender, cholesterol, blood pressure, inflammation, etc.) with minimal or no additional costs. In this article, we make examples derived from the nephrology literature to show the usefulness of cross-sectional studies in clinical and epidemiological research.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease treated with hemodialysis or peritoneal dialysis, hypertension is very common and often poorly controlled. Blood pressure (BP) recordings obtained before or after hemodialysis display a J-shaped or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar hemodynamic setting related with dialysis treatment. Elevated BP by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnea and the use of erythropoietin-stimulating agents may also be involved. Nonpharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium-volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease (ESRD) treated with haemodialysis or peritoneal dialysis, hypertension is common and often poorly controlled. Blood pressure (BP) recordings obtained before or after haemodialysis display a J- or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar haemodynamic setting related to dialysis treatment. Elevated BP detected by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnoea and the use of erythropoietin-stimulating agents may also be involved. Non-pharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium and volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

Effect of Nocturnal Hemodialysis versus Conventional Hemodialysis on End-Stage Renal Disease: A Meta-Analysis and Systematic Review

Objectives

The purpose of this study is to assess the efficacy and safety of nocturnal hemodialysis on end-stage renal disease (ESRD) patients.

Methods

We searched Medline, EmBase, and the Cochrance Central Register of Controlled Trials for studies up to January 2016. Analysis was done to compare variant outcomes of different hemodialysis schedules, including mortality, cardiovascular-associated variables, uremia-associated variables, quality of life (QOL), side-effects, and drug usage.

Results

We collected and analyzed the results of 28 studies involving 22,508 patients in our meta-analysis. The mortality results in this meta-analysis indicated that the nocturnal hemodialysis (NHD) group was not significantly different from conventional hemodialysis (CHD) group (Mortality: OR: 0.75; 95% confidence intervals (CIs): 0.52 to 1.10; p = 0.145), but the CHD group had significantly fewer number of hospitalizations than the NHD group (OR: 1.54; 95%CI: 1.32 to 1.79; p<0.001). NHD was superior to CHD for cardiovascular-associated (left ventricular hypertrophy [LVH]: SMD: -0.39; 95%CI: -0.68 to -0.10; p = 0.009, left ventricular hypertrophy index [LVHI]: SMD: -0.64; 95%CI: -0.83 to -0.46; p<0.001) and uremia-associated intervention results (Serum albumin: SMD: 0.89; 95%CI: 0.41 to 1.36; p<0.001). For the assessment of quality of life, NHD treatment significantly improved the patients’ QOL only for SF36-Physical Components Summary (SMD: 0.43; 95%CI: 0.26 to 0.60; p<0.001). NHD intervention was relatively better than CHD for anti-hypertensive drug usage (SMD: -0.48; 95%CI: -0.91 to -0.05; p = 0.005), and there was no difference between groups in our side-effects assessment.

Conclusion

NHD and CHD performed similarly in terms of ESRD patients’ mortality and side-effects. NHD was superior to CHD for cardiovascular-associated and uremia-associated results, QOL, and drug usage; for number of hospitalizations, CHD was relatively better than NHD.

Health economic evaluation of paricalcitol(®) versus cinacalcet + calcitriol (oral) in Italy. [corrected]

BACKGROUND AND OBJECTIVE

Chronic kidney disease (CKD) is a highly morbid disorder. The most severe form of CKD is end-stage renal disease (ESRD), in which the patient requires some form of renal replacement therapy to survive. The increasing incidence, prevalence, and costs of ESRD are major national healthcare concerns. The objective of this study was to determine the cost effectiveness of two innovative therapies, paricalcitol versus cinacalcet + calcitriol (oral) in patients with CKD stage 5 (CKD 5) in the healthcare setting in Italy in 2013.

METHODS

A Markov process model was developed employing data sources from the published literature, paricalcitol clinical trials, official Italian price/tariff lists, and national population statistics. The analysis is based on a comparison of treatment with paricalcitol versus cinacalcet + calcitriol (oral) in CKD 5. The perspective of the study was that of the payer [Italian National Health Service (INHS)]. The primary efficacy outcomes in the paricalcitol and cinacalcet + calcitriol (oral) clinical trials (reduction of secondary hyperparathyroidism, complications, and mortality) were extrapolated to effectiveness outcomes: number of life-years gained (LYG) and number of quality-adjusted life-years (QALYs). Clinical and economic outcomes were discounted at 3 %.

RESULTS

The base-case analysis is based on a 5-year time horizon. From the INHS perspective, the use of paricalcitol leads to a cost saving of €1,853 and an increase in LYG (0.136) and a gain in QALYs (0.089). Consequently, the use of paricalcitol is dominant over the use of combination cinacalcet + calcitriol (oral paricalcitol leads to cost savings and a higher effectiveness). Sensitivity analyses confirmed the robustness of the model.

CONCLUSION

The results showed that the favorable clinical benefit of paricalcitol results in positive health economic benefits. This study suggests that the use of paricalcitol in patients with ESRD may be cost effective from the perspective of the INHS.

New Pathogenic Concepts and Therapeutic Approaches to Oxidative Stress in Chronic Kidney Disease

In chronic kidney disease inflammatory processes and stimulation of immune cells result in overproduction of free radicals. In combination with a reduced antioxidant capacity this causes oxidative stress. This review focuses on current pathogenic concepts of oxidative stress for the decline of kidney function and development of cardiovascular complications. We discuss the impact of mitochondrial alterations and dysfunction, a pathogenic role for hyperuricemia, and disturbances of vitamin D metabolism and signal transduction. Recent antioxidant therapy options including the use of vitamin D and pharmacologic therapies for hyperuricemia are discussed. Finally, we review some new therapy options in diabetic nephropathy including antidiabetic agents (noninsulin dependent), plant antioxidants, and food components as alternative antioxidant therapies.

Cost Effectiveness of Sucroferric Oxyhydroxide Compared with Sevelamer Carbonate in the Treatment of Hyperphosphataemia in Patients Receiving Dialysis, from the Perspective of the National Health Service in Scotland

BACKGROUND

Hyperphosphataemia is common and harmful in patients receiving dialysis. Treatment options include noncalcium-based phosphate binders such as sevelamer carbonate (SC) and sucroferric oxyhydroxide (PA21).

OBJECTIVE

The aim of this study was to determine the health economic impact of PA21-based strategies compared with SC-based strategies, from the perspective of the Scottish National Health Service (NHS).

METHODS

A Markov model was constructed based on data from a randomised clinical trial comparing PA21 and SC. Model input parameters were derived from published literature, national statistics and unpublished sources. Costs (price year 2012) and effects were discounted at 3.5 %. Analysis with a lifelong time horizon yielded the incremental cost-effectiveness ratio (ICER), expressed as cost or savings per quality-adjusted life-year (QALY) gained or forgone. Deterministic and probabilistic sensitivity analysis was performed to explore uncertainties around assumptions and model input parameters.

RESULTS

In the base-case analysis, phosphorus reductions for PA21 and SC were 1.93 and 1.95 mg/dL. Average undiscounted survival was estimated to be 7.61 years per patient in both strategies. PA21 patients accrued less QALYs (2.826) than SC patients (2.835), partially due to differential occurrence of side effects. Total costs were ₤ 13,119 and ₤ 14,728 for PA21 and SC, respectively (difference per patient of ₤ 1609). By using PA21 versus SC, one would save ₤ 174,999 (or ₤ 123,463 when including dialysis and transplantation costs) for one QALY forgone. A scenario modelling the nonsignificant reduction in mortality (relative risk 0.714) observed in the trial yielded an ICER for PA21 of ₤ 22,621 per QALY gained. In probabilistic sensitivity analysis of the base-case, PA21 was dominant in 11 %, and at least cost-effective in 53 %, of iterations, using a threshold of ₤ 20,000 per QALY gained.

CONCLUSIONS

The use of PA21 versus SC in hyperphosphataemic patients being intolerant of calcium-based phosphate binders may be cost saving and yields only very limited disadvantages in terms of quality-adjusted survival. PA21 appears to be cost-effective from the perspective of the Scottish NHS.

Treatment options for dyslipidemia in chronic kidney disease and for protection from contrast-induced nephropathy

Chronic kidney disease (CKD) is highly prevalent worldwide and represents a major cardiovascular risk factor. Dyslipidemia is present in most patients with CKD and further worsens CKD, creating a vicious cycle. The treatment of CKD-related dyslipidemia has been a controversial topic. The use of statins is recommended in all stages of CKD, but it appears to reduce cardiovascular and renal events only in the early CKD stages, up to stage 3. The use of atorvastatin has proven very beneficial; thus, the earliest we start statin treatment, the better for the patient. Atorvastatin and pitavastatin do not need dose adjustments at any level of renal function. Fibrates can be administered in mixed hyperlipidemia, combined with statins in early CKD stages. Omega-3 fatty acids are useful for treating hypertriglyceridemia in CKD. Antibodies against proprotein convertase subtilisin/kexin type 9 hold promise for a better control of dyslipidemia and a greater reduction of cardiovascular risk.

The PPARβ/δ agonist GW501516 attenuates peritonitis in peritoneal fibrosis via inhibition of TAK1-NFκB pathway in rats

Peritoneal fibrosis is a common consequence of long-term peritoneal dialysis (PD), and peritonitis is a factor in its onset. Agonist-bound peroxisome proliferator-activated receptors (PPARs) function as key regulators of energy metabolism and inflammation. Here, we examined the effects of PPARβ/δ agonist GW501516 on peritonitis in a rat peritoneal fibrosis model. Peritoneal fibrosis secondary to inflammation was induced into uremic rats by daily injection of Dianeal 4.25% PD solutions along with six doses of lipopolysaccharide before commencement of GW501516 treatment. Normal non-uremic rats served as control, and all rats were fed with a control diet or a GW501516-containing diet. Compared to control group, exposure to PD fluids caused peritoneal fibrosis that was accompanied by increased mRNA levels of monocyte chemoattractant protein-1, tumor necrotic factor-α, and interleukin-6 in the uremic rats, and these effects were prevented by GW501516 treatment. Moreover, GW501516 was found to attenuate glucose-stimulated inflammation in cultured rat peritoneal mesothelial cells via inhibition of transforming growth factor-β-activated kinase 1 (TAK1), and nuclear factor kappa B (NFκB) signaling pathway (TAK1-NFκB pathway), a main inflammation regulatory pathway. In conclusion, inhibition of TAK1-NFκB pathway with GW501516 may represent a novel therapeutic approach to ameliorate peritonitis-induced peritoneal fibrosis for patients on PD.

Extraosseous calcification in end-stage renal disease: from visceral organs to vasculature

In earlier days, periarticular accumulations of calcium phosphate causing tumor-like depositions were considered the result of passive precipitation and referred to as metastatic calcifications. From sophisticated computer tomographic studies and growing insight, we have learned that calcifications in the cardiovascular system are far more threatening and in fact one of the most important sequela of end-stage renal disease. The histologic characteristic of uremia-related calcification is arteriosclerosis of the media. In addition, there is atherosclerosis of the intima, due to the high prevalence of classic cardiovascular risk factors in renal disease. The two vascular features can frequently exist at different sites in the vasculature. Novel diagnostic techniques are helping to elucidate the pathogenetic mechanisms of active conversion of vascular smooth muscle cells to osteochondritic cells. Through this process, extensive calcification of the central and peripheral vasculature ensues, influenced by different promotors and inhibitors. Calciphylaxis is a special form of extraosseous calcification leading to skin necrosis. The factors that trigger the development of calciphylaxis are not completely understood, but this syndrome shares part of the pathophysiologic basis of extraosseous calcification in general. However, the therapeutic approach must be prompt and aggressive, because of the poor prognosis. Frequently, a fatal outcome cannot be avoided in calciphylaxis.

Renal anemia control in Lithuania: influence of local conditions and local guidelines

Erythropoietin stimulating agents had a long haul in Lithuania—we had no epoetin till 1994 and there was no intravenous iron in 2001–2004. The aim of this study was to assess the changes of renal anemia control in hemodialysis patients from early independence of Lithuania till nowadays and to evaluate the link of anemia with hospitalization rates and survival and hemoglobin variability in association with mortality. In December of each year since 1996 all hemodialysis centers have been visited and data has been collected using special questionnaires. The history of renal anemia control in Lithuania was complicated; however, a significant improvement was achieved: 54.7% of hemodialysis patients reached the target hemoglobin; all patients have a possibility of treatment with epoetin and intravenous iron. The involuntary experiment with an intravenous iron occurred in Lithuania because of economic reasons and confirmed the significant role of intravenous iron in the management of renal anemia. Hemoglobin below 100 g/L was associated with a 2.5-fold increase in relative risk of death and 1.7-fold increase in relative risk of hospitalization in Lithuanian hemodialysis patients. Although hemoglobin variability was common in Lithuanian hemodialysis patients, we did not find the association between hemoglobin variability and all-cause mortality in our study.

Type of vascular access and location in online hemodiafiltration and its association with patient's perception of health-related quality of life

PURPOSE

The aim of this work is to evaluate the patient-reported health-related quality of life (HRQOL), according to the type and location of vascular access used for dialysis procedure.

METHODS

In this transversal study, 322 end-stage renal disease (ESRD) patients under online hemodiafiltration (OL-HDF, 59.63% males; 64.9±14.3 years) were enrolled. Arteriovenous fistula (AVF) was used by 252 patients (78.3%), whereas 70 patients (21.7%) had a central venous catheter (CVC). Besides AVF location, data on comorbidities, hematological data, iron status, dialysis adequacy, nutritional and inflammatory markers were collected. Moreover, the patients' reported HRQOL score, using the Kidney Disease Quality of Life-Short Form, was evaluated.

RESULTS

ESRD patients using CVC as vascular access presented a decrease in four SF-36 domain scores, namely physical functioning, emotional well-being, role-emotional and energy/fatigue when compared with those using AVF as vascular access. Additionally, these patients also showed significant differences in ESRD target areas, namely decline in cognitive function and quality of social interaction domains. When comparing the variables according to the localization of the AVF, significant differences were found in three SF-36 domain scores, namely physical functioning, pain and general health. Moreover, we also found significant differences in ESRD target areas, namely symptoms/problem list, effects of kidney disease and quality of social interaction domains.

CONCLUSIONS

Our results showed that ESRD patients under OL-HDF using AVF as vascular access had higher HRQOL scores in several domains when compared with those using CVC. Additionally, we also found that dialysis patients using AVF in the left forearm presented with higher HRQOL scores.

Matrix Producing Cells in Chronic Kidney Disease: Origin, Regulation, and Activation

Chronic injury to the kidney causes kidney fibrosis with irreversible loss of functional renal parenchyma and leads to the clinical syndromes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Regardless of the type of initial injury, kidney disease progression follows the same pathophysiologic processes characterized by interstitial fibrosis, capillary rarefaction and tubular atrophy. Myofibroblasts play a pivotal role in fibrosis by driving excessive extracellular matrix (ECM) deposition. Targeting these cells in order to prevent the progression of CKD is a promising therapeutic strategy, however, the cellular source of these cells is still controversial. In recent years, a growing amount of evidence points to resident mesenchymal cells such as pericytes and perivascular fibroblasts, which form extensive networks around the renal vasculature, as major contributors to the pool of myofibroblasts in renal fibrogenesis. Identifying the cellular origin of myofibroblasts and the key regulatory pathways that drive myofibroblast proliferation and transdifferentiation as well as capillary rarefaction is the first step to developing novel anti-fibrotic therapeutics to slow or even reverse CKD progression and ultimately reduce the prevalence of ESRD. This review will summarize recent findings concerning the cellular source of myofibroblasts and highlight recent discoveries concerning the key regulatory signaling pathways that drive their expansion and progression in CKD.

Paricalcitol and cardiorenal outcome: from the IMPACT study to clinical practice

Chronic kidney disease mineral bone disorders (CKD-MBD) encompass laboratory, vascular and bone abnormalities that might portend a poor prognosis in CKD. In spite of a great effort in elucidating the CKD-MBD natural history and pathogenesis, the underlying mechanisms are still largely unknown. However, a deficit in vitamin D is commonly reported as one of the first steps in CKD-MBD, and numerous epidemiological studies have associated serum vitamin D levels with different markers of cardiovascular disease and the risk of death in different populations. We herein summarize current evidence that links vitamin D deficiency to an adverse outcome and the results of the most recent clinical trials that have investigated the impact of paricalcitol supplementation on hard outcome in CKD patients.