Effect of Acetazolamide and Furosemide on Obesity-induced Glomerular Hyperfiltration

Summary

Background:

Obesity is associated with a high prevalence of chronic kidney disease.The glomerular hyperfiltration associated with obesity may play a role in the pathogenesis of obesity associated chronic kidney disease. Attenuation of hyperfiltration by pharmacological means may slow down the development and progression of chronic renal failure. The investigators have previously shown that acetazolamide, a proximally acting diuretic that activates tubuloglomerular feedback(TGF) by increasing solute delivery to the Macula DENSA, abates glomerular hyperfiltration. The present study was designed to test the hypothesis that this decrease in hyperfiltration is specific to acetazolamide and not due to a non specific diuretic effect. The aim of the present study is to compare the effects of furosemide and acetazolamide on glomerular hemodynamics in subjects with severe obesity.

Methods:

A randomized double-blind crossover controlled design will be used. Fifteen obese subjects and ten subjects with normal body weight will participate in the study. Obese subjects will undergo measurement of glomerular filtration rate (GFR)(inulin clearance), renal plasma flow (RPF) (p-aminohippuric acid clearance), filtration fraction, fractional excretion of lithium (FE LI) and blood pressure, before and after intravenous administration of furosemide 2 mg. and acetazolamide 5 mg/kg BW. Ten subjects with normal body weight will undergo measurement of renal function without administration of diuretics.

Conditions

• Obesity-induced Hyperfiltration

Interventions

DRUG

Furosemide first, then Acetazolamide

Two renal function studies will be performed: one before and after intravenous furosemide and the second before and after intravenous acetazolamide. Subjects will receive 300 mg of lithium carbonate at 22.00 the day before the renal function tests. A priming dose of inulin (50 mg/kg) and p-aminohippuric acid (8 mg/kg) will be administered and a 200-300 ml p.o water load will be given. Thereafter, inulin and p-aminohippuric acid will be infused continuously. After the first 60 minutes, 8 accurately timed urine collections of 30 to 40 minutes will be obtained by spontaneous voiding. After the first 4 timed urine collections, participants will receive intravenous furosemide 2 mg/5min or intravenous acetazolamide 5 mg/kg/5 min.Four other times urine collections will be performed thereafter.

DRUG

Acetazolamide first, then Furosemide

Two renal function studies will be performed: one before and after intravenous acetazolamide and the second before and after intravenous furosemide. Subjects will receive 300 mg of lithium carbonate at 22.00 the day before the renal function tests.A priming dose of inulin (50 mg/kg) and p-aminohippuric acid (8 mg/kg) will be administered and a 200-300 ml p.o water load will be given. Thereafter, inulin and p-aminohippuric acid will be infused continuously. After the first 60 minutes, 8 accurately timed urine collections of 30 to 40 minutes will be obtained by spontaneous voiding. After the first 4 timed urine collections, participants will receive intravenous furosemide 2 mg/5min or intravenous acetazolamide 5 mg/kg/5 min.Four other times urine collections will be performed thereafter.

Sponsors & Collaborators

• Rabin Medical Center

  lead OTHER

Principal Investigators

• Boris Zingerman, MD · Rabin Medical Center

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

55 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2010-07-31

Primary Completion

2014-05-31

Completion

2014-05-31

Countries

• Israel

Study Locations