Diagnosing Natriuretic Peptide Deficiency

Study Overview
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Brief Summary
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In this pilot study, the investigators will determine the response of the natriuretic peptide (NP) hormone system after a dose of intravenous dexamethasone (a steroid medication). The goal of the proposed project is to generate preliminary data that will be used to develop power calculations, inform cutoff ranges, and inform the timing of the NP response for larger subsequent studies. Aim: To determine the range of distribution and time course of natriuretic peptide (NP) responses to a single dose of dexamethasone IV 4 mg in healthy lean individuals. Hypothesis: Determination of the NP responses (the range and time course of changes in NP levels) to dexamethasone in 10 healthy individuals will inform the time course and frequency of blood sampling in a definitive prospective study, as well as enable investigators to perform a sample size calculation for a definitive prospective study.

Detailed Description
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see above

Official Title
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Diagnosing Natriuretic Peptide Deficiency: A Pilot Study

Conditions
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Healthy, Lean

Intervention / Treatment
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* Drug: Dexamethasone


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Men and women ages 18-50 years BMI 18.5 to <25 kg/m^2 Exclusion Criteria: Significant use of systemically-absorbed glucocorticoids currently or for an extended period of time during the prior 6 months Current use of antihypertensive medications Current use of metformin, or any antidiabetic medications (which could affect glucose and insulin levels) Current use of medications known to affect dexamethasone metabolism, including phenytoin, rifampin, carbamazepine, troglitazone, and barbiturates Active, clinically significant infection at time of visit History of adrenal insufficiency or Cushing's syndrome Prior or current cardiovascular disease, renal disease, or liver disease Diabetes mellitus, pre-diabetes, impaired fasting glucose, or impaired glucose tolerance Atrial fibrillation Bleeding disorder or anemia Elevated Liver Functions Tests > 2 times upper limit of normal Estimated glomerular filtration rate < 60 ml/min HbA1c > 5.7 Abnormal sodium or potassium level Positive pregnancy test, women of child-bearing age not practicing birth control, women who are breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy<br>10 Healthy subjects will undergo study procedures at four study visits. All subjects will undergo the same procedures and interventions. | Drug: Dexamethasone<br>* A single dose of dexamethasone IV 4 mg will be administered.<br>* Other names: Dexamethasone IV;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in NT-proANP From Baseline to 8 Hours | Change in natriuretic peptide levels after drug administration | baseline and 8 hours | 
| Changes in NT-proBNP From Baseline to 8 Hours | Change in natriuretic peptide levels after drug administration | Baseline and 8 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in NT-proANP | Change in natriuretic peptide levels after drug administration from baseline to 24 hours, 48 hours, and 72 hours | baseline, 24 hours, 48 hours and 72 hours | 
| Changes in NT-proBNP | Change in natriuretic peptide levels after drug administration from baseline to 24 hours, 48 hours, and 72 hours | at baseline, 24 hours, 48 hours and 72 hours | 
| BNP (B-type Natriuretic Peptide) | Natriuretic peptide levels after drug administration | 0-8 hrs, 24 hrs, 48 hrs, 72 hrs after drug administration | 
| ANP (Atrial Natriuretic Peptide) | Natriuretic peptide levels after drug administration | 0-8 hrs, 24 hrs, 48 hrs, 72 hrs after drug administration |