The Influence of Rosiglitazone on the Diuretic Effect of Furosemide and Amiloride

• ClinicalTrials.gov Identifier: NCT00285805
• Recruitment Status: Completed
• First Posted: February 2, 2006
• Last Update Posted: August 24, 2010
• Sponsor: Radboud University
• Information provided by: Radboud University

Study Description

Brief Summary:

Thiazolidinedione derivates (TZD's) are Peroxisome-Proliferator-Activated-Receptor-γ agonists (PPARγ-agonists) and enhance insulin sensitivity. One of the side effects, however, is the fact that subjects treated with these drugs seem to be more prone to fluid retention. The precise mechanism of rosiglitazone-related fluid retention is unknown, but it is clear that either primary or secondary renal sodium retention is part of the mechanism. Furthermore in observational studies, TZD-related oedema seems to be resistant to loop diuretic therapy. The recent finding that rosiglitazone induces upregulation of the epithelial sodium channel (ENaC) in the kidney could be the explanation for TZD-related fluid retention and the observed resistance to loop diuretics. In the present human in-vivo study the following hypothesis will be tested:

Rosiglitazone treatment stimulates the activity of ENaC in the distal nephron, which enhances the natriuretic effect of amiloride and decreases the natriuretic effect of furosemide in parallel.

Condition or disease	Intervention/treatment	Phase
Insulin Resistance	Drug: Rosiglitazone versus placebo; Drug: response (sodium excretion) to amiloride infusion; Drug: response (sodium excretion) to furosemide infusion	Not Applicable

Detailed Description:

This is a randomized, placebo-controlled, double-blind, single-centre, cross-over study with 4 weeks of wash out comparing placebo with rosiglitazone 4 mg bid for 9 weeks treatment periods. Randomization of the treatment sequence will be computer-generated, with a sequentially driven allocation. Randomization and blinding will be performed at the department of Clinical Pharmacy. After 8 (furosemide) and 9 (amiloride) weeks in each period the end-point experiments will be performed. During all visits (week 0, 4, 8, 9) of each period, adverse events and pill compliance will be recorded. In addition, physical examination, foot volume and bio-impedance measurements will be performed and safety chemical, and hematological profiles will be determined. Only at start and at 8 weeks in each period, glucose, insulin and HbA1c are measured. All visits and interventions will be performed at the Clinical Research Center Nijmegen (CRCN).

Furosemide end-point experiment Each participant will attend the hospital at 8 a.m. after an overnight fast and abstinence of alcohol and caffeine for 20 hours, delivering a 24-hour urine collection and the present morning voiding. The previous three days each participant will adhere to an individualized diet containing 150 mmol of sodium and 80 mmol of potassium prescribed by a dietician. First, blood will be collected to measure fasting glucose and insulin concentrations. Then the subject will be given an individualized breakfast including 1 cup of water. Afterwards a brachial vein will be cannulated and connected to a Braunpump (10 ml/hr NaCl 0.9%), followed by blood drawing for safety and vascular hormone measurements (aldosterone, Atrial Natriuretic Peptide (ANP), Brain Natriuretic Peptide (BNP), Vascular Endothelial Growth Factor (VEGF) and renin).

A bolus of furosemide (40 mg) will be injected through a small cannule in a vein of the contra-lateral arm, just after bladder emptying. Venous blood samples will be drawn at 0, 15, 30, 45, 60, 90,120, 150, 180, 240, 300, 360, 420 and 480 minutes after bolus injection to measure plasma furosemide levels. The participants will be asked to urinate regularly, at least hourly. The exact time of voiding and the urine volume will be recorded. Two urine samples will be taken. In one sample, sodium and creatinine concentrations will be measured while the other sample will be light-protected and immediately frozen for measurement of furosemide levels later on. To prevent dehydration each participant will be asked to drink tap water equal to the volume of diuresis in the previous hour. During the test the participant will be sitting on a bed. At noon the participant will be offered an individualized lunch. After 8 hours each participant will leave the hospital with the instruction to adhere to the diet without fluid restrictions and to collect the urine for up to 24 hours after start of the experiment.

Amiloride end-point experiment Until amiloride infusion the procedures will be similar. At time point 0, venous infusion of a loading dose of amiloride will be started (150 μg/kg in 60 minutes) followed by maintenance infusion (0.20 μg/kg/min) for 4 hours. Amiloride will be obtained as a sterile powder in the form of amiloride HCl/2H2O . Directly before use, the powder will be dissolved in NaCl 0,9% up to a concentration of 1 mg/ml and the solution was filtered through a 0.22 μm Millipore filter. Venous blood for measurement of the amiloride concentration will be sampled at 60, 180, 300 and 420 minutes. All the other procedures will be similar to the furosemide experiment.

Pharmacokinetic considerations on the amiloride-dose The peak plasma levels 3-4 hours after intake of 10 or 20 mg amiloride are 20 μg/L (32) and 38-40 μg/L respectively(33). These concentrations are well below the half maximal inhibitory concentration (IC50) of amiloride for Na+/H+ and Na+/Ca2+-transporters and the α1-receptor, but well above the IC50 for ENaC(34). Using the pharmacokinetic characteristics of amiloride(35) we calculated the required amiloride infusion in order to reach a steady-state concentration between 30-45 μg/L.

Exosome extraction:

Urinary exosomes will be isolated by ultracentrifugation and ENaC abundance will be measured by immunoblotting as previously described (19;36) and normalized to urine creatinine levels. 4 µg of protein lysed in Laemmli buffer will be loaded on 8% SDS-PAGE. PAGE, blotting and blocking of the PVDF membranes will be done as previously described. Membrane will be incubated with 1:4000-diluted affinity-purified rabbit α-ENaC antibody (Rossier BC, Lausanne, Switzerland), followed by 1:5,000-diluted goat anti-rabbit IgG's as secondary antibody coupled to horseradish peroxidase. Blotting signals will be visualized using enhanced chemiluminescence. The samples will be normalized for the expression level of α-ENaC in placebo treatment and indicated as percentage.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 13 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Triple (Participant, Care Provider, Investigator)
• Primary Purpose: Treatment
• Official Title: The Influence of Rosiglitazone on the Diuretic Effect of Furosemide and Amiloride. A Double-blind Placebo Controlled Cross Over Study.
• Study Start Date: February 2006
• Actual Primary Completion Date: October 2006
• Actual Study Completion Date: November 2006

Arms and Interventions

Arm	Intervention/treatment
Rosiglitazone-placebo	Drug: Rosiglitazone versus placebo; Drug: response (sodium excretion) to amiloride infusion; Drug: response (sodium excretion) to furosemide infusion
placebo-rosiglitazone	Drug: Rosiglitazone versus placebo; Drug: response (sodium excretion) to amiloride infusion; Drug: response (sodium excretion) to furosemide infusion

Outcome Measures

Primary Outcome Measures :

1. Difference in cumulative sodium excretion over an 8-hour period following amiloride infusion after 9 weeks of treatment with either rosiglitazone or placebo. [ Time Frame: week: 9, 22 ]

Secondary Outcome Measures :

1. The difference in ER50 (urine excretion rate of furosemide with the half maximal effect) after 8 weeks of treatment with either rosiglitazone or placebo. [ Time Frame: week: 8, 21 ]
2. The difference in the ENac abundance in exosomes in the urine measured after 8 weeks of treatment with either rosiglitazone or placebo [ Time Frame: week: 8, 21 ]

Eligibility Criteria

• Ages Eligible for Study: 30 Years to 70 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

• Healthy but with 2 features of the metabolic syndrome (AHA/NHLBI) (16)
• Willing and able to provide a signed and dated written informed consent.
• Male or female subject aged between 30 and 70 years

Exclusion Criteria:

• Fasting glucose > 7,0 mmol/L or the use of hypoglycaemic agents. If fasting plasma glucose is between 6.1 and 7,0 mmol/L,an oral 75 g glucose test will be performed to exclude diabetes mellitus.
• Exposure to a PPAR-g agonist during the last 4 months or a documented significant hypersensitivity to a PPAR-g agonist.
• Participant in another study.
• Angina or heart failure (NYHA I-IV).
• Clinically significant liver disease (3 times the upper normal limit of ALAT, ASAT, AF, γGT or LDH)
• Clinically significant anaemia (male Hb < 6,9 mmol/L, female < 6,25 mmol/L)
• Creatinin clearance < 40 mL/min
• Pregnancy, lactation
• Alcohol or drug abuse. Liquorice

Contacts and Locations

Locations

Netherlands

Radboud University Nijmegen medical centre

Nijmegen, Netherlands, 6500 HB

Sponsors and Collaborators

Radboud University

Investigators

• Principal Investigator: Paul Smits, MD, PhD; Radboud University Nijmegen Medical Centre, head of department Pharmacology and Toxicology.
• Principal Investigator: Cees JJ Tack, MD, PhD; Radboud University Nijmegen Medical Centre, chairman of the departement of diabetology

More Information

Publications:

Nesto RW, Bell D, Bonow RO, Fonseca V, Grundy SM, Horton ES, Le Winter M, Porte D, Semenkovich CF, Smith S, Young LH, Kahn R; American Heart Association; American Diabetes Association. Thiazolidinedione use, fluid retention, and congestive heart failure: a consensus statement from the American Heart Association and American Diabetes Association. October 7, 2003. Circulation. 2003 Dec 9;108(23):2941-8. Review.

Hong G, Lockhart A, Davis B, Rahmoune H, Baker S, Ye L, Thompson P, Shou Y, O'Shaughnessy K, Ronco P, Brown J. PPARgamma activation enhances cell surface ENaCalpha via up-regulation of SGK1 in human collecting duct cells. FASEB J. 2003 Oct;17(13):1966-8. Epub 2003 Aug 15.

Guan Y, Hao C, Cha DR, Rao R, Lu W, Kohan DE, Magnuson MA, Redha R, Zhang Y, Breyer MD. Thiazolidinediones expand body fluid volume through PPARgamma stimulation of ENaC-mediated renal salt absorption. Nat Med. 2005 Aug;11(8):861-6. Epub 2005 Jul 10.

Niemeyer NV, Janney LM. Thiazolidinedione-induced edema. Pharmacotherapy. 2002 Jul;22(7):924-9. Review.

van Meyel JJ, Smits P, Russel FG, Gerlag PG, Tan Y, Gribnau FW. Diuretic efficiency of furosemide during continuous administration versus bolus injection in healthy volunteers. Clin Pharmacol Ther. 1992 Apr;51(4):440-4.

Baba WI, Lant AF, Smith AJ, Townshend MM, Wilson GM. Pharmacological effects in animals and normal human subjects of the diuretic amiloride hydrochloride (MK-870). Clin Pharmacol Ther. 1968 May-Jun;9(3):318-27.

Pisitkun T, Shen RF, Knepper MA. Identification and proteomic profiling of exosomes in human urine. Proc Natl Acad Sci U S A. 2004 Sep 7;101(36):13368-73. Epub 2004 Aug 23.

• Responsible Party: Paul Smits, Radboud University Nijmegen Medical Center
• ClinicalTrials.gov Identifier: NCT00285805
• Other Study ID Numbers: AR-49653-3
• First Posted: February 2, 2006
• Last Update Posted: August 24, 2010
• Last Verified: October 2008

Keywords provided by Radboud University:

Rosiglitazone; Furosemide; Amiloride; Epithelial sodium channel; Sodium excretion

Additional relevant MeSH terms:

Insulin Resistance; Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Rosiglitazone; Amiloride; Furosemide; Diuretics; Natriuretic Agents; Physiological Effects of Drugs; Sodium Potassium Chloride Symporter Inhibitors; Membrane Transport Modulators; Molecular Mechanisms of Pharmacological Action; Hypoglycemic Agents; Acid Sensing Ion Channel Blockers; Sodium Channel Blockers; Epithelial Sodium Channel Blockers; Diuretics, Potassium Sparing