Search

The article discusses the role of Hypoxia-inducible factor-prolyl hydroxylase (HIF-PHIs) inhibitors in changing the management of iron in end-stage renal disease (ESRD). HIF-PHIs are noted to initiate some of the mechanisms triggered by hypoxia which can lead to downstream responsive pathways under the conditions of normal actual tissue-oxygen tensions.

Hemodialysis via arteriovenous fistulas (AVFs) is associated with reduced morbidity and mortality when compared to alternative vascular accesses, yet few patients in the United States start dialysis with AVFs. Recent studies have demonstrated higher quality of care for many conditions in Veterans Affairs' Medical Centers (VAMC); however, differences in quality of vascular access care are unknown. We used patient-level data (6/05-5/06) from Medicare claims ( n = 25,912) to compare the proportions of AVF among incident patients at VAMC-affiliated ( n = 20) and unaffiliated dialysis ( n = 1631) facilities. Multivariate logistic regression was used to determine whether associations of access type with facility type were independent. Compared to non-VAMC patients, a larger proportion of VAMC patients started dialysis with AVFs (20.9% versus 11.6% in non-VAMC patients; OR 1.99, [95% CI 1.55-2.56]). Although attenuated, this finding persisted in models adjusted for demographics (OR 1.65 [95% CI 1.28-2.13]) and demographics with comorbidities (OR 1.70 [95% CI 1.31-2.20]). However, after accounting for pre end-stage renal disease (ESRD) care, similar proportions of VAMC and non-VAMC patients started hemodialysis with an AVF (OR 1.28 [95% CI 0.98-1.66]). In conclusion, patients receiving care at VAMC-associated facilities were more likely to start hemodialysis with AVFs, perhaps because of better pre-ESRD care. Nonetheless, AVF rates remain suboptimal, indicating a need for ongoing vascular access evaluation and improvement. [ABSTRACT FROM AUTHOR]

Disorders of calcium and phosphorus metabolism are associated with significant morbidity and mortality in patients with advanced chronic kidney disease. These patients typically require oral phosphate binders to maintain phosphorus homeostasis, but the choice of which among several agents to use has been actively investigated and debated. Recent debate has been polarized between those who favor calcium-based binders for their proven efficacy and relatively low cost and those who favor sevelamer for its putative beneficial effects on inflammatory biomarkers and vascular calcification. This review summarizes the current state of the art of prescribing phosphate binders, ranging from large-scale clinical trials to focused mechanistic studies, and proposes that the available evidence does not conclusively prove the relative superiority of any one binder. [ABSTRACT FROM AUTHOR]

Anemia is common in chronic kidney disease (CKD) due to a state of erythropoietin deficiency. Erythropoietin therapy has been used for approximately 20 years to correct anemia in CKD and to improve both subjective and objective outcomes. Guidelines that establish a hemoglobin (Hb) goal for anemia correction in CKD patients are largely based on observational data. Controversy still exists, however, because outcomes have not been consistent with various degrees of anemia correction. The number of prospective randomized trials investigating the effects of anemia correction on cardiovascular (CV) morbidity and mortality in CKD patients, an already high-risk group, is limited. With respect to improving CV outcomes in the CKD population, the currently available trial data caution against raising Hb levels in CKD patients to approach more “normal” physiologic ranges. The disappointing experience with the trial data must be weighed against the beneficial associations of erythropoietin therapy that have been generated from observational data. Establishing the ideal target Hb ranges for anemia correction in CKD patients remains a dynamic process and leaves many gray areas to be further elucidated. Here, we present a case that underscores the need to consider the study design when reviewing the data at a population level in order to determine what is most appropriate for our patient. [ABSTRACT FROM AUTHOR]

Leptin is a mediator of metabolism and disease in a variety of organ systemsmost notably as an agent of energy stores. Howeverits role in renal disease as an inflammatory agent as well as its potential impact on the cachexia of uremia have sparked new interest in the molecule for nephrologists. This review elucidates the complex uremic statethe historical discovery of leptin and its physiologyand the potential interactions leptin has on both the progression of kidney disease as well as the morbidity and mortality of end-stage renal disease. [ABSTRACT FROM AUTHOR]

Congestive heart failure (CHF) and hyperkalemia are the two leading reasons for emergency dialysis among individuals with end-stage renal disease (ESRD). While hemodialysis provides definitive treatment of both hyperkalemia and volume overload among ESRD patients, for those who present outside of "regular dialysis hours," institution of dialysis may be delayed. Nondialytic management can be instituted immediately and should be the initial therapy in the management of hyperkalemia and CHF in these individuals. Current available evidence does not allow conclusions as to whether treatment with nondialytic strategies alone results in different outcomes than nondialytic strategies coupled with emergent hemodialysis. Therefore, whether or not nondialytic management alone is appropriate remains a matter of individual judgment that should be decided on a case-by-case basis. [ABSTRACT FROM AUTHOR]

Congestive heart failure (CHF) and hyperkalemia are the two leading reasons for emergency dialysis among individuals with end-stage renal disease (ESRD). While hemodialysis provides definitive treatment of both hyperkalemia and volume overload among ESRD patients, for those who present outside of “regular dialysis hours,” institution of dialysis may be delayed. Nondialytic management can be instituted immediately and should be the initial therapy in the management of hyperkalemia and CHF in these individuals. Current available evidence does not allow conclusions as to whether treatment with nondialytic strategies alone results in different outcomes than nondialytic strategies coupled with emergent hemodialysis. Therefore, whether or not nondialytic management alone is appropriate remains a matter of individual judgment that should be decided on a case-by-case basis. [ABSTRACT FROM AUTHOR]

Biostatistics seeks to answer the question "Is there a difference?" in the rate of a disease or characteristic among subgroups of patients. The goal of this article is to introduce and define measures used in epidemiology and discuss different types of analyses in clinical research with an emphasis on the concepts and implications of the analyses rather than the mathematics. The implications of the use of measures such as incidence and prevalence, as well as odds, risk, and hazards ratios may affect study conclusions. An understanding of the distinction between these summary measures is essential. The concepts of univariate and multivariate analyses, a discussion of what it means to control for potential confounders, and a description of statistical power and significance are also presented. These concepts are integral to the design and analysis of clinical studies. An understanding of their advantages and applications will enhance the reader's ability to understand and evaluate the literature. [ABSTRACT FROM AUTHOR]

Epidemiology is the basic medical science that focuses on the distribution and determinants of disease frequency in human populations. An understanding of the tools of epidemiology is helpful in defining the limitations of medical research and evaluating the conclusions of studies. This is the second in a series of three articles whose objective is to present the basic concepts of epidemiology and biostatistics, highlighted by examples of these concepts applied in the medical literature studying patients receiving dialysis. This article describes the study designs of case-control, cohort, and randomized trials and issues in the conduct and analysis of each. Several studies examining the association between hematocrit and survival of dialysis patients are discussed. Their differences in design and methods are discussed in the context of their effect on study conclusions. The goal of this article is to present the reader with the issues of study design and the limitations they impose on study conclusions. Through the examination of these methods, the reader will be able to rigorously examine study methods and understand how design affects study conclusions and their application to patient care. [ABSTRACT FROM AUTHOR]

Epidemiology is the basic medical science that focuses on the distribution and determinants of disease frequency in human populations. An understanding of the tools of epidemiology is helpful in defining the limitations of medical research and evaluating the conclusions of studies. This is the first in a series of three articles whose objective will be to present the basic concepts of epidemiology and biostatistics. Examples of each of the tools and limitations discussed from studies of patients with end-stage renal disease (ESRD) will be presented to provide the reader with a practical application of the concepts. This series of articles will help the reader to weigh methods and study designs to understand the appropriate conclusions that may be drawn from any data. [ABSTRACT FROM AUTHOR]

The end-stage renal disease (ESRD) program has a significant overrepresentation of racial and ethnic minority groups. The increased susceptibility of nonwhite populations to ESRD has not been fully explained and probably represents a complex interplay of genetic, cultural, and environmental influences. Because the program delivers care under a uniform health care payment system, it represents a unique environment in which to explore variation in health care delivery. A number of disparities in outcomes and delivery of ESRD care have been noted for racial minority participants. These include possible overdiagnosis of hypertensive nephrosclerosis, decreased provision of renal replacement therapy, limited referral for home dialysis modalities, underprescription of dialysis, increased use of synthetic grafts rather than fistulas as permanent angioaccess, and delayed wait-listing for renal transplantation. Transplantation inequities mean that black patients are likely to remain on dialysis relatively longer, so that their susceptibility to less than optimal processes of care increases disproportionately. Improved survival and quality of life (QOL) for blacks with ESRD may have encouraged provider complacency about racial disparities in the ESRD program and in particular about referral for transplantation. It is also apparent that minority ESRD patients may, similar to their non-ESRD counterparts, be referred less frequently for invasive cardiovascular (CV) procedures. Despite these observations of inequality in ESRD care, the adjusted mortality for minority participants in the ESRD program are better than for the majority population. This seeming paradox may define an opportunity to improve outcomes for minorities with ESRD even more. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the clinical uses and interpretation of iron studies in chronic kidney diseases (CKD). Particular focus is given to the two ways in which iron transport and distribution differ in CKD patients from individuals with normal kidney function. Other topics discussed include the criteria for iron deficiency, Kidney Disease: Improving Global Outcomes guidelines on iron supplementation, and indicators of iron deficiency.

Population-based studies of maintenance hemodialysis patients have demonstrated a reproducible relationship between the dose of hemodialysis and mortality and morbidity outcomes. In these analyses, which have aggregated hemodialysis patient subgroups, improved outcomes are associated with greater doses of hemodialysis. However, remarkable counterintuitive findings are observed if patients are analyzed by subgroups based on their race, gender, and anthropometric and blood-based biomarkers of nutritional state. For example, blacks generally receive lower doses of hemodialysis than whites, but enjoy relatively improved survival; patients who receive the highest doses of hemodialysis have an increased death risk; and the dose response curve between hemodialysis and survival is altered based on the patients' body mass index. These seemingly paradoxical relationships between hemodialysis dose and patient survival can be explained because of the use of mathematical urea kinetic constructs as clinical outcome predictors; they integrate a measure of solute removal (K x t) with an anthropometric surrogate of nutrition, the urea distribution volume (V). Both these measures have an independent influence on patient survival and in some clinical circumstances are of unequal power as clinical outcome predictors. These complex interactions must be kept in perspective as clinical care is delivered in the context of hemodialysis dose. [ABSTRACT FROM AUTHOR]

The article offers information on the study regarding the increased risk of restless legs syndrome (RLS) to patients that undergone maintenance dialysis. It mentions the hypothesis that those patients scheduled earlier in the day for dialysis have less risk to RLS compared to those who are scheduled later in the day. It states the use of Comprehensive Dialysis Study (CDS), a stratified random sampling design, conducted by United State Renal Data System (USRDS).