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| Sponsors and Collaborators: |
Ottawa Hospital Research Institute Heart and Stroke Foundation of Ontario University of Ottawa |
|---|---|
| Information provided by: | Ottawa Hospital Research Institute |
| ClinicalTrials.gov Identifier: | NCT00759967 |
Purpose
More than 80% of patients with end stage renal disease have hypertension; 70% of whom are poorly controlled using conventional Hemodialysis therapy. An expanded extracellular fluid volume and an increase in peripheral vascular resistance as a result of hemodynamic/trophic effects of an increased sympathetic nerve activity, angiotensin II, asymmetrical dimethyl arginine, and decreased nitric oxide are the most frequently quoted mechanisms contributing to hypertension in this population. The intermittent nature of conventional hemodialysis treatments (4 hours, 3 days/week) results in the majority of patients having a sustained expansion of the extracellular fluid volume that likely contributes to the activation of neurohormonal pathways. However, daily therapy including short daily hemodialysis (2 hours, 6 days/week) and nocturnal hemodialysis (6-8 hours, 5-6 days/week) improve or even normalize blood pressure. Short daily hemodialysis appears to improve blood pressure secondary to a reduction in extracellular fluid volume (7,8) whereas the improvement in blood pressure with nocturnal hemodialysis occurs by a reduction in peripheral vascular resistance (8,9,10). This is consistent with the Katzarski et al experience (7-8 hours, 3 days/week) and one randomized controlled trial in which blood pressure control was due to normalization of extracellular fluid volume in some patients and a reduction in peripheral vascular resistance in others. The majority of the studies in daily dialysis are observational, do not include a run-in period to optimize blood pressure management and have not explored the mechanisms of improvement in blood pressure in detail. We have designed a 9 month study to determine if the mechanism by which short daily hemodialysis is associated with an improvement in blood pressure control is secondary to changes in sympathetic nervous system activity and/ or extracellular fluid volume. Additionally we would like to explore the potential impact of short daily dialysis, compared to conventional dialysis, on markers of inflammation and oxidative stress in detail.
| Condition | Intervention | Phase |
|---|---|---|
|
End Stage Renal Disease |
Procedure: muscle sympathetic nerve activity measurement Procedure: Bio impedence testing |
Phase II |
| Study Type: | Interventional |
| Study Design: | Treatment, Randomized, Open Label, Active Control, Crossover Assignment, Efficacy Study |
| Official Title: | Randomized Cross-Over Study of Short Daily Hemodialysis Compared to Conventional Hemodialysis to Determine the Mechanisms of Hypertension Control |
| Estimated Enrollment: | 20 |
| Study Start Date: | September 2007 |
| Estimated Study Completion Date: | September 2010 |
| Estimated Primary Completion Date: | June 2010 (Final data collection date for primary outcome measure) |
Patients with end stage renal disease have an adjusted risk of cardiovascular mortality that is 10-20 times greater than the general population. Of the modifiable risk factors, hypertension occurs in 80% of patients with end stage renal disease and is poorly controlled in 70% of patients. In several observational studies of daily hemodialysis, blood pressure has improved despite a reduction in the number of antihypertensive medications. A randomized crossover study in short daily hemodialysis also showed an improvement in systolic blood pressure and a reduction in left ventricular mass index. In limited investigation, the mechanism(s) responsible for the improvement in blood pressure have been attributed to a reduction in extracellular fluid volume (short daily) and a reduction in peripheral vascular resistance (nocturnal hemodialysis). The studies to date have been limited by failing to include a run in phase to optimize extracellular fluid volume prior to the initiation of daily dialysis. Additionally, only one study used a standardized algorithm for the management of blood pressure which is vital as the treatments are not blinded. We have designed a randomized, unblinded, 9 month cross-over study to determine the mechanism of blood pressure control on patients receiving conventional (3 times /week) HD to short daily HD (6 times /week 2 hrs/tx). After completing a 3 month run-in phase on conventional HD in which patient's dry weight and antihypertensive medications will be adjusted using a standardized algorithm, patients are to be randomized to a 3 month cross-over of daily HD versus conventional HD. The mechanism of improved blood pressure control will be explored using bioelectrical impedance to measure extracellular fluid volume (ECFV) and muscle sympathetic nerve activity (MSNA) as well as plasma catecholamines to measure the activity of the sympathetic nervous system. Additionally the effect of short daily HD, compared to conventional HD, on reactive oxygen species and markers of inflammation will be examined in Dr. Rhian Touyz lab. Lastly we will determine the patient's treatment preference.
Eligibility| Ages Eligible for Study: | 18 Years and older |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Exclusion Criteria:
Contacts and Locations| Canada, Ontario | |
| The Ottawa Hospital | Recruiting |
| Ottawa, Ontario, Canada, K1H 7W9 | |
| Contact: Judy Cheesman, RN 613-738-8400 ext 82514 jcheesman@ohri.ca | |
| Contact: Laurie Coveduck, RN 613-738-8400 ext 81621 lcoveduck@toh.on.ca | |
| Principal Investigator: Deborah Zimmerman, MD | |
More Information
| Study ID Numbers: | 2006 77401H |
| Study First Received: | September 24, 2008 |
| Last Updated: | September 29, 2008 |
| ClinicalTrials.gov Identifier: | NCT00759967 History of Changes |
| Health Authority: | Canada: Health Canada |
|
Randomized Cross-Over Conventional Daily Hemodialysis |
|
Renal Insufficiency Urologic Diseases Renal Insufficiency, Chronic Kidney Failure, Chronic |
Kidney Diseases Kidney Failure Hypertension |
|
Renal Insufficiency Urologic Diseases Renal Insufficiency, Chronic |
Kidney Failure, Chronic Kidney Diseases Kidney Failure |
