Publications by authors named "Peter N Van Buren"

Background: Extracellular volume (ECV) overload and endothelial cell dysfunction are mortality risk factors in hemodialysis (HD) patients. Endothelin-1 (ET-1), an endothelium-derived vasoconstrictive peptide, is associated with poor outcomes in HD patients. We hypothesized there would be associations between ET-1 and ECV overload in hypertensive HD patients.

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Background: Hyperphosphatemia occurs frequently in end-stage renal disease patients on hemodialysis and is associated with increased mortality. Hyperphosphatemia contributes to vascular calcification in these patients, but there is emerging evidence that it is also associated with endothelial cell dysfunction.

Methods: We conducted a cross-sectional study in hypertensive hemodialysis patients.

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Natriuretic peptide levels are elevated in persons with chronic kidney disease (CKD) stages 1-3, but it remains unclear whether this is associated with extracellular volume excess or early cardiovascular changes. We hypothesized that patients with CKD stages 1-3 would have evidence of cardiovascular changes, which would associate with brain natriuretic peptide (BNP), amino-terminal-pro-BNP (NT-pro-BNP), and patient-reported symptoms.Outpatients with CKD stages 1-3 and non-CKD controls were enrolled.

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Background: Various causes of hypokalemia (HK) from renal potassium wasting, including distal renal tubular acidosis (RTA), have been described in lupus nephritis (LN). We report a phenomenon of otherwise unexplained HK among a population with LN.

Methods: From our population of 403 patients with LN, we identified a cohort of 20 patients with idiopathic HK, defined by serum potassium <3.

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Introduction: Extracellular volume (ECV) predicts mortality in hemodialysis patients, but it is difficult to assess clinically. Peridialytic blood pressure (BP) measurements can help ECV assessment. Orthostatic BP is routinely measured clinically, but its association with ECV is unknown.

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Background: Hypertension and extracellular volume (ECV) overload are interrelated mortality risk factors in hemodialysis (HD) patients, but confounding related to changes in ECV and vasoconstriction during and between treatments obfuscate their relationship. We sought to clarify independent contributions of post-HD ECV and intradialytic changes in vasoconstriction on ambulatory blood pressure (BP) in patients with and without recurrent intradialytic hypertension (IH).

Methods: In this prospective observational study, we obtained measurements of pre- and post-HD ECV with bioimpedance spectroscopy (BIS), pre- and post-HD total peripheral resistance index and 44-h ambulatory BP.

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Visit-to-visit blood pressure variability (BPV) is associated with cardiovascular events in the general population. Data are scarce in chronic kidney disease. We hypothesized that BPV would be associated with cardiovascular outcomes, death, and end-stage kidney disease (ESKD) and that diuretics would modify these associations in patients with chronic kidney disease.

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Background/aims: Extracellular volume (ECV) overload is a mortality risk factor in hemodialysis patients, but no standard approach exists to objectively assess this clinically. We aimed to quantify relationships between slopes of repeated intradialytic blood pressure (BP) measurements and ECV.

Methods: In a cross-sectional study of 71 hemodialysis patients, we calculated BP slopes from all intradialytic measurements using Gaussian regression.

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Hypertension is a comorbidity that is present in the majority of end-stage renal disease patients on maintenance hemodialysis. This population is particularly unique because of the dynamic nature of blood pressure (BP) during dialysis. Modest BP decreases are expected in most hemodialysis patients, but intradialytic hypotension and intradialytic hypertension are two special situations that deviate from this as either an exaggerated or paradoxical response to the dialysis procedure.

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Moxifloxacin is commonly prescribed in the inpatient and outpatient management of community-acquired pneumonia and other common infections. We report a case of a 76-year-old man who developed severe neutropenia after several days of treatment for community-acquired pneumonia. The patient had a history of alcohol abuse; however, there were no other offending medications prescribed, and a thorough laboratory workup for other possible causes of neutropenia was negative.

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Purpose Of Review: Intradialytic hypertension occurs regularly in 10--15% of hemodialysis patients. A large observational study recently showed that intradialytic hypertension of any magnitude increased mortality risk comparable to the most severe degrees of intradialytic hypotension. The present review review discusses the most recent evidence underlying the pathophysiology of intradialytic hypertension and implications for its management.

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Background/aims: Intradialytic hypertension (IH) occurs frequently in some hemodialysis patients and increases mortality risk. We simultaneously compared pre-dialysis, post-dialysis and changes in extracellular volume and hemodynamics in recurrent IH patients and controls.

Methods: We performed a case-control study among prevalent hemodialysis patients with recurrent IH and hypertensive hemodialysis controls.

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Hypertension is one of the most common cardiovascular comorbidities in end-stage renal disease patients on hemodialysis. Its complex pathophysiology is related to extracellular volume overload, increased vascular resistance stemming from factors related to uremia or abnormal signaling from the failing kidneys, as well as the unique blood pressure changes that take place during and between hemodialysis treatments. Despite the changing nature of blood pressure over time in hemodialysis patients, hypertension diagnosed in or out of the hemodialysis unit is associated with increased cardiovascular morbidity and mortality.

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Background/aims: Intradialytic hypertension (IH) patients have higher mortality risk than other hemodialysis patients and have been shown to have higher ambulatory blood pressure (BP). We hypothesized that interdialytic BP patterns would differ in IH patients and hypertensive hemodialysis controls.

Methods: We consecutively screened hemodialysis patients at our university-affiliated units.

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Background: Intradialytic hypertension is a condition where there is an increase in blood pressure (BP) from pre- to post-hemodialysis; this condition has been recently identified as an independent mortality risk factor in hypertensive hemodialysis patients. The mechanisms and management of intradialytic hypertension have been explored in numerous research studies over the past few years.

Summary: Patients with intradialytic hypertension have been found to be more chronically volume overloaded compared to other hemodialysis patients, although no causal role has been established.

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The Systolic Blood Pressure Intervention Trial (SPRINT) will compare treatment to a systolic blood pressure goal of <120 mm Hg to treatment to the currently recommended goal of <140 mm Hg for effects on incident cardiovascular, renal, and neurologic outcomes including cognitive decline. The objectives of this analysis are to compare baseline characteristics of African American (AA) and non-AA SPRINT participants and explore factors associated with uncontrolled blood pressure (BP) by race. SPRINT enrolled 9361 hypertensive participants aged older than 50 years.

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Background: Phosphate binders are the cornerstone of hyperphosphatemia management in dialysis patients. Ferric citrate is an iron-based oral phosphate binder that effectively lowers serum phosphorus levels.

Study Design: 52-week, open-label, phase 3, randomized, controlled trial for safety-profile assessment.

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Background And Objectives: Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are the cornerstones of pharmacologic therapy in diabetic nephropathy. Mineralocorticoid receptor blockers reduce proteinuria as single agents or add-on therapy to other renin-angiotensin-aldosterone system-inhibiting drugs in these patients. The long-term benefits and ultimate role of mineralocorticoid receptor blockers in diabetic nephropathy remain unknown.

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Hypertension commonly coexists with diabetes, and its prevalence is even higher in the presence of diabetic kidney disease. The pathogenesis of hypertension in this population stems from increased extracellular volume and increased vasoconstriction that results from mechanisms that may be attributed to both diabetes and the eventual impairment of renal function. Antihypertensive therapy aimed at reducing blood pressure remains a primary goal in preventing the incidence of diabetic kidney and slowing its progression.

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Diabetic nephropathy is the leading cause of end-stage renal disease in the United States. The progression of kidney disease in patients with diabetes can take many years, and interventions such as glycemic control, blood pressure control, and inhibition of the renin-angiotensin-aldosterone system have been shown to slow this progression. Despite the implementation of these strategies, the number of patients with diabetes that ultimately develop end-stage renal disease remains high.

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Background: Intradialytic hypertension, a phenomenon where blood pressure increases during hemodialysis, is associated with increased mortality in hemodialysis patients. The proportion of patients in which intradialytic hypertension persists over time is unknown.

Methods: In a retrospective cohort study, we studied all patients from our outpatient hemodialysis units that received =1 month of treatments during the period from January to August 2010.

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Purpose Of Review: Hypertension is common in hemodialysis patients and contributes to this population's high risk for cardiovascular morbidity and mortality. Patients with intradialytic hypertension, or increases in blood pressure during hemodialysis, have been shown to have the highest risk for these outcomes. The purpose of this review is to describe new findings that shed light on the epidemiology and pathophysiology of intradialytic hypertension and discuss how a better understanding of these mechanisms may lead to improved blood pressure management and outcomes in hemodialysis patients.

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