Pavlos Malindretos

Slow Intravenous Iron Administration Does Not Aggravate Oxidative Stress and Inflammatory Biomarkers during Hemodialysis: A Comparative Study between Iron Sucrose and Iron Dextran

Background/Aims: Fast intravenous (i.v.) iron administration during hemodialysis (HD) is associated with the augmentation of oxidative stress and the increase in inflammatory biomarkers, which are also induced by the hemodialysis procedure itself. The aim of this study was to investigate if slow i.v. iron administration would aggravate the status of oxidative stress and inflammatory biomarkers during a hemodialysis session. Methods: Twenty dialysis patients 30–92 years of age that were iron replete and had values for hemoglobin, transferrin saturation and serum ferritin among recommended goals were evaluated in three separate hemodialysis sessions. In the first session patients did not receive any iron treatment, whereas during the second and the third session patients received slow (60 min) i.v. infusions of 100 mg of iron sucrose and 100 mg of iron dextran, respectively. Blood samples were drawn before the hemodialysis session, 15 min after the end of iron administration and at the end of the hemodialysis session in all occasions, for the measurement of markers of oxidant stress (oxidized LDL and ischemia-modified albumin) and inflammation (high-sensitivity C-reactive protein, interleukin-6 and tumor necrosis factor-α). Results: Oxidized LDL was not significantly altered during hemodialysis and this pattern was similar between the three occasions studied. In contrast, ischemia-modified albumin was significantly increased and this effect was also not different between the net hemodialysis and the occasions of iron administration. High-sensitivity CRP, IL-6 and TNF-α were all significantly elevated during hemodialysis and again both types of iron administration did not produce significant changes in this pattern. Conclusion: We did not find an increase in the markers of oxidation/inflammation studied, after slow i.v. iron administration during hemodialysis session.

Hemodialysis Reduces Augmentation Index but Not Aortic or Brachial Pulse Wave Velocity in Dialysis-Requiring Patients

Background/Aims: Arterial stiffening characterizes the vasculature of end-stage renal disease (ESRD) patients and is a strong predictor of their cardiovascular morbidity and mortality. Previous studies evaluating the effect of hemodialysis on large artery elasticity gave contradictory results. This study aimed to investigate the impact of hemodialysis on arterial stiffness and wave reflections on chronic hemodialysis patients. Methods: A total of 51 stable ESRD patients on maintenance hemodialysis were evaluated before and after the first and second dialysis session of the week. Arterial stiffness was assessed by measuring aortic and brachial pulse wave velocity (PWV). Central arterial pressure waveform parameters were estimated by radial artery applanation tonometry. Heart rate-adjusted augmentation index [AIx(75)] was used as measure of wave reflections. Results: During both dialysis sessions systolic blood pressure (SBP) and pulse pressure (PP) at brachial artery and central aorta were reduced. AIx(75) was decreased in first and second weekly dialysis session (27.5 ± 1.2 vs. 21.0 ± 1.5, p < 0.001 and 24.7 ± 1.2 vs. 20.5 ± 1.5, p < 0.001, respectively). In contrast, aortic and brachial PWV remained unchanged during both dialysis sessions. Changes in AIx(75) during hemodialysis were associated with changes in central aortic SBP, PP and ejection duration. Conclusions: This study shows that hemodialysis does not acutely affect arterial stiffness, but reduces wave reflections from periphery. This dissociation between effects of hemodialysis on PWV and AIx(75) may reflect differential impact on large and small branches of the arterial tree.

A study of the association of higher parathormone levels with health-related quality of life in hemodialysis patients.

Secondary hyperparathyroidism (SHPT) is associated with poor outcome including mortality, hospitalization, as well as greater healthcare resource utilization and costs in chronic kidney disease (CKD). We hypothesized that SHPT is also associated with poor self reported health-related quality of life (HRQOL) in prevalent hemodialysis (HD) patients. We conducted a case-control study in patients with CKD receiving longterm HD treatment, in six dialysis clinics in Greece. HRQOL was estimated with the KDQOL-SFTM questionnaire, version 1.3, which includes 43 kidney disease targeted items, and 36 items that provide a generic core and an overall health rating item, with a higher score reflecting a more favorable health state. A total of 156 completed the questionnaire, 50 with high parathormone levels (i.e., PTH > 300 pg/ml and or under vitamin D receptor activators, mean: 329 ± 160.9 pg/ml) and 106 with low parathormone levels (PTH < 300 pg/ml, mean: 132.4 ± 69.0 pg/ml) in a 2 : 1 randomization assignment. Patients with high and with low PTH were 62.1 ± 14.9 and 65.9 ± 14.2 y old and the median dialysis vintage time was 31 and 37 months, respectively. There were no significant differences regarding the presence of comorbidities between groups. Patients with high PTH, compared to patients with low PTH, had lower pain component summary (57.6 ± 33.5 vs. 69.2 ± 28.9; p = 0.041) and physical component summary (41.0 ± 23.8 vs. 50.0 ± 20.8; p = 0.031). Both pain component summary and physical component summary differences remained significant after adjustment for age, gender and vintage (p = 0.036 and p = 0.029, respectively). Low PTH patients scored better in 18 out of 23 subscales. In HD patients, SHPT appears to be associated with worse pain component summary score (p = 0.036) and physical component summary score (p = 0.029). Additional studies are needed to verify these associations and to examine whether correction of SHPT can improve HRQOL.

Pharmacological management of hypertensive emergencies and urgencies: focus on newer agents

Introduction: Hypertensive crises are categorized as hypertensive emergencies and urgencies depending on the presence of acute target-organ damage; the former are potentially life-threatening medical conditions, requiring urgent treatment under close monitoring. Although several short-acting intravenous antihypertensive agents are approved for this purpose, until recently little evidence from proper trials on the relative merits of different therapies was available. Areas covered: This article discusses in brief the pathophysiology, epidemiology and diagnostic approach of hypertensive crises and provides an extensive overview of established and emerging pharmacological agents for the treatment of patients with hypertensive emergencies and urgencies. Expert opinion: Agents such as sodium nitroprusside, nitroglycerin and hydralazine have been used for many years as first-line options for patients with hypertensive emergencies, although their potential adverse effects and difficulties in use were well known. With time, equally potent and less toxic alternatives, including nicardipine, fenoldopam, labetalol and esmolol are increasingly used worldwide. Recently, clevidipine, a third-generation dihydropyridine calcium-channel blocker with unique pharmacodynamic and pharmacokinetic properties was added to our therapeutic armamentarium and was shown in clinical trials to reduce mortality when compared with nitroprusside. In view of such evidence, a change in pharmacological treatment practices for hypertensive crises toward newer and safer agents is warranted.

Adaptation and Validation of the Kidney Disease Quality of Life-Short Form Questionnaire in the Greek Language

Aim: The aim of this study was to examine the validity, reproducibility and internal consistency of a Greek translation of the Kidney Disease Quality of Life-Short Form (KDQOL-SF) questionnaire. Methods: The KDQOL-SF questionnaire was translated from English to Greek and was administered in 240 randomly selected patients undergoing hemodialysis in six Renal Units in Greece. The instrument’s validity was tested by examining the association between patient’s KDQOL-SF scores and comorbidity assessed with the Index of Coexistent Disease. Reproducibility was examined by readministering the questionnaire in 50 randomly selected patients within 1 month. Internal consistency was assessed by estimating Cronbach’s alpha coefficient. Results: Patients were divided into two groups according to the severity of comorbidity assessed with the Index of Coexistent Disease. Those with less comorbid conditions had significantly higher scores in most components of the KDQOL-SF questionnaire, confirming its validity. The correlation coefficients between the two administrations of the instrument ranged from 0.88 to 0.98 for each of the main components, which was above the desired level of 0.85. Cronbach’s alpha coefficient ranged from 0.91 to 0.92 for the various components, values well above the minimum desired 0.70 level. Conclusions: The present study shows that the Greek version of the KDQOL-SF questionnaire has high validity, reproducibility and internal consistency. Production of validated translations of the KDQOL-SF questionnaire in various languages will help promote health-related quality of life of end-stage renal disease patients all over the world.

Consultants for the American Journal of Nephrology 2007

Mario Cozzolino Farhard Danesh Robert Danziger John Daugirdas Katherine Dell Luca De Nicola Janice Douglas Thomas DuBose Carolyn Ecelbarger Allison Eddy Charles Edelstein Beatrice Edwards Belkıs Erbas Ronald Falk Ken Farrington Sahar Fathallah-Shaykh Murray Favus Leon Ferder Albert Ferro Michael Fischer Steven Fishbane Barry Freedman Gordon Freeman Elena Gagliardini C. Garlichs Fumitake Gejyo P. Gentilini Cheryl Gilmartin Richard Glassock Ehud Goldhammer David Goldsmith Stuart Goldstein Jennifer Gooch Laurence Greenbaum Dimitrios Grekas Hans Grosse-Wilde Mehmet Haberal Peter Hart Tomoko Hayashida Peter Heering Klaus Hocherl Radovan Hojs Susan Hou Priscilla How Reiko Inagi Ajay Israni Edwin Jackson Sara Jandeska Vanita Jassal Kevin Abbott Dale Abrahamson Adel Afifi Rajiv Agarwal Cu-Rie Ahn Maie Albader Farah Ali Ahsan Arozullah John Asplin Brad Astor Aslihan Avci Carla Avesani Mindy Banks Vinod Bansal Mary Barchman Amelia Bartholomew Amy Barton Pai David Basile F. Baud John Beltrame Carsten Bergmann Rajendra Bhimma Daniel Bichet Peter Blake Amy Bobrowski W. Kline Bolton Michael Braun Carolyn Brecklin Ellen Brooks Edward Brown Vito Campese Caterina Canavese Zemin Cao Lucio Cardoso Daniel Catanzaro Tak Mao Chan Rene Chang Julie Chao Monique Cho Yongwon Choi Nina Clark Steven Coca David Cohen Gabriel Contreras Mark Cooper Dominic Cosgrove Scott Cotler Adrian Covic Daniel Coyne