Intervention Study to Compare the Natriuretic Effects of Enalapril on Low and High Salt Diet

Not Applicable

Completed

• Conditions: Salt-sensitive Hypertension
• Interventions: Drug: Fenoldopam

• Registration Number: NCT01324245
• Lead Sponsor: Georgetown University

Brief Summary

The kidney plays a crucial role in maintaining salt balance by two opposing physiological mechanisms: the renal dopaminergic system which enhances salt excretion and the renin-angiotensin system (RAS) which causes salt retention. Salt-sensitive hypertension occurs when this balance is altered or abnormal. We hypothesized that this balance is influenced by salt intake: therefore dietary salt affects the natriuretic response to the renal dopaminergic agonist Fenoldopam, and the Angiotensin Converting Enzyme inhibitor, Enalapril.

In this trial we study normal salt balance mechanisms in salt resistant adults with normal blood pressure.

Detailed Description

Eight adults of both genders and all races were studied in this double blind placebo controlled cross over study with randomization of the order of interventions. After 5 days each on low salt (about 1 gram/day) and high salt (about 6 grams/day)diet, with a washout period of at least four weeks in between, every subject was treated with Enalapril and Placebo on two consecutive days, followed by a Fenoldopam infusion for three hours, during which natriuresis and renal function testing were performed.

Study Timeline

• Study Start: 2002-11
• Status Verified: 2003-11
• Primary Completion: 2005-12
• Study Completion: 2006-05
• Study First Submitted: 2011-03-25
• Study First Submitted QC: 2011-03-25
• Last Update Submitted: 2011-03-25
• Study First Posted: 2011-03-28
• Last Update Posted: 2011-03-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 45

Inclusion Criteria

• Volunteers
• Healthy
• Normal Blood Pressure

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Exclusion Criteria

• Renal Impairment
• Obesity
• Salt sensitive increase in blood pressure

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Enalapril	Fenoldopam	2.5 mg every 12 hours for two doses

Primary Outcome Measures

Name	Time	Method
Urinary sodium excretion	During the trial: a 3 hour fenoldopam infusion	All subjects received placebo/enalapril in a randomized counterbalanced fashion in both phases. Phase 1 was on low salt, while Phase 2 was on high salt. All subjects received a 3 hour fenoldopam infusion, during which time urinary sodium excretion was measured as the primary outcome bvariable.

Secondary Outcome Measures

Name	Time	Method
Renal Plasma Flow	During 3 hour fenoldopam infusion	In order to explain physiologically the effects of fenoldopam on urinary sodium excretion on high and low salt diet, with and wothout enalapril, renal plasma flow was measured during the infusion using PAH clearance

Trial Locations

Locations (1)

Georgetown University Medical Center; 🇺🇸 Washington, District of Columbia, United States