The Natriuretic Peptide Response to Saline Infusion

Study Overview
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Brief Summary
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The primary objective is to evaluate the overarching hypothesis that obese and black individuals have relatively lower circulating natriuretic peptide levels compared with lean and white individuals. Conventional clinical assays for measurement of circulating natriuretic peptides display substantial overlap, precluding determination of the basis of the relative natriuretic peptide deficiency previously observed in these groups. We will study lean or obese, black or white, healthy adult subjects with intravenous (IV) saline infusion as a stimulus for natriuretic peptide production and release. We will measure circulating levels of natriuretic peptide isoforms using mass spectrometry that allows the specific identification of proBNP 1-108 and its cleavage product BNP 1-32.

Official Title
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The Natriuretic Peptide Response to Saline Infusion

Conditions
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Obesity

Intervention / Treatment
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* Drug: Normal Saline 0.9% Infusion Solution Bag


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18 and 65 years; BMI between 18 and 25 (lean) or 30 and 40 kg/m2 (obese); self-reported race of either black or white; otherwise healthy with no chronic comorbidities. Exclusion Criteria: History of diabetes mellitus Currently pregnant History of cardiac disorder including heart failure, cardiomyopathy, myocardial infarction, coronary revascularization, abnormal stress test, uncontrolled arrhythmia or arrhythmia requiring treatment, congenital heart disease, pericardial disease. History of hypertension defined as taking anti-hypertensive medications or untreated hypertension with systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg at most recent clinical visit or screening visit. Obstructive lung disease History of chronic kidney disease History of liver disease or cirrhosis Uncontrolled thyroid dysfunction History of solid organ transplant History of malignancy other than basal or squamous cell skin cancer Inability to lie flat for 6 hours

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Saline<br>Each participant will receive a saline infusion of normal saline 0.9%NaCl | Drug: Normal Saline 0.9% Infusion Solution Bag<br>* Participants will receive a normal saline infusion at a rate of 10ml per unit of body surface area per minute for 120 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in circulating levels of proBNP 1-108 from baseline to 6 hours | proBNP 1-108 is a protein made by the heart. The change in circulating levels will be measured in response to saline infusion | Saline infusion will be given for 2 hours (with 4 hour observation) with blood samples collected at hourly intervals for 7 hours total | 
| Change in circulating levels of proBNP 1-32 from baseline to 6 hours | BNP 1-32 is a hormone made by the heart. The change in circulating levels will be measured in response to saline infusion | Saline infusion will be given for 2 hours (with 4 hour observation) with blood samples collected at hourly intervals for 7 hours total |