Focus of Study of Healthy Adults
Conditions
Brief summary
This proposal hypothesizes that oral supplementation with sodium nitrite or nitrate will result in in vivo conversion of nitrate to nitrite and nitrite to nitric oxide with limited toxicity in the doses proposed in healthy adult normal volunteers. We utilize a powerful in vivo technique (pharmacokinetic testing) and are the first to design inorganic nitrate and nitrite capsules for cardiovascular disease.
Detailed description
Preclinical and clinical research over the last decade has revealed the important vasoprotective effects of nitrates and nitrites with regards to reduction in blood pressure, vascular inflammation and endothelial dysfunction. New findings suggest an effect of nitrate and nitrite therapy in the regulation of glucose-insulin homeostasis. Development of an oral formulation of nitrate and nitrite salts is attractive, whereby nitrite would ensure rapid acting effects upon absorption, while the nitrate would continuously provide a slow formation of nitrite over a prolonged period of time via the enterosalivary circulation pathway. For this reason, development of an oral formulation of nitrate and nitrite salts is attractive, whereby nitrite would ensure rapid acting effects upon absorption, while the nitrate would continuously provide a slow formation of nitrite over a prolonged period of time via the enterosalivary circulation pathway. This study aims to establish the pharmacokinetics, metabolism and interconversion of nitrate to nitrite and nitrite to nitric oxide in vivo in healthy adult normal volunteers.
Interventions
DRUG15Nitrogen(15N)-labeled sodium nitrite
15Nitrogen(15N)-labeled sodium nitrite 20 mg once
DRUG15Nitrogen(15N)-labeled sodium nitrate
15Nitrogen(15N)-labeled sodium nitrate 1,000 mg once
Sponsors
Gladwin, Mark, MD
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18-60 years * Systolic blood pressure ≤130 and diastolic blood pressure ≤85 mm Hg
Exclusion criteria
* Positive urine pregnancy test or breastfeeding * Concurrent use of medications affecting glucose or lipid metabolism * Recent addition or change in dosing of hormonal contraceptive medications (oral contraceptive pill, intrauterine device, DepoProvera) * Current use of ≥2 anti-hypertensive agents regardless of blood pressure control or normotensive on a single agent * Current use of phosphodiesterase 5 inhibitors or organic nitrates * Not stable on treatments for the prior three months or not planning to remain on current dose of medications for blood pressure, contraception, etc * Known chronic psychiatric or medical conditions including diabetes, liver or kidney disease or obesity syndromes * Smoker
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peak Plasma Nitrate Concentration Over 24 Hour Study Period | measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses | Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak Plasma Nitrite Concentration Over 24 Hour Study Period | measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses | Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak Red Blood Cell (RBC) Iron-nitrosyl Hemoglobin (NO-Hb) Concentrations Over 24 Hour Study Period | measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses | Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Peak Change in Diastolic Blood Pressure Over 24 Hour Study Period | measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 0.75 hours reported | Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak 15Nitrogen Nitro-conjugated Linoleic Acid (cLA) Concentrations Over 24 Hour Study Period | measured at time 0 (trough), every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose | Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak Percentage Level of Methemoglobin Over 24 Hour Study Period | measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses | Post-doses refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak Change in Heart Rate Over 24 Hour Study Period | measured at 0 (baseline), every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 1.5 hours for nitrate and 24 hours for nitrite | Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Percent Platelet Activation at 6 Hours | measured at 0 (baseline), 6 and 24 hours post-dose | at timepoint with greatest change from 0 (trough); Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period; percentage of platelets that express 2 specific markers identifying activated platelets (CD41 and CD62-P) were quantified using flow cytometry |
| Peak Change in Mean Arterial Pressure Over 24 Hour Study Period | measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 0.75 hours reported | Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
| Peak Change in Systolic Blood Pressure Over 24 Hour Study Period | measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 1.5 hours reported | Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period |
Countries
United States
Participant flow
Recruitment details
Healthy adult participants were recruited between October 2012 and October 2013.
Pre-assignment details
11 participants recruited; 11 screened; 0 excluded
Participants by arm
| Arm | Count |
|---|---|
| Entire Study Population Includes groups randomized to received oral 15N-labeled sodium nitrate first and sodium nitrite first. | 10 |
| Total | 10 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Second Intervention | Withdrawal by Subject | 0 | 1 |
Baseline characteristics
| Characteristic | Entire Study Population |
|---|---|
| Age, Continuous | 30.4 years |
| Diastolic blood pressure | 75 mmHg STANDARD_DEVIATION 9.3 |
| Mean arterial pressure | 91 mmHg STANDARD_DEVIATION 6.8 |
| Methemoglobin | 1.0 percentage level of methemoglobin STANDARD_DEVIATION 0.2 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 9 Participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 5 Participants |
| Systolic blood pressure | 122 mmHg STANDARD_DEVIATION 9.2 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 9 / 10 | 9 / 11 |
| serious Total, serious adverse events | 0 / 10 | 0 / 11 |
Outcome results
Primary
Peak Plasma Nitrate Concentration Over 24 Hour Study Period
Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Plasma Nitrate Concentration Over 24 Hour Study Period | 769 microMolar (microM) | Standard Error 38 |
| Oral 15N-labeled Sodium Nitrite | Peak Plasma Nitrate Concentration Over 24 Hour Study Period | 41 microMolar (microM) | Standard Error 3.7 |
Primary
Peak Plasma Nitrite Concentration Over 24 Hour Study Period
Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Plasma Nitrite Concentration Over 24 Hour Study Period | 0.51 microM | Standard Error 0.1 |
| Oral 15N-labeled Sodium Nitrite | Peak Plasma Nitrite Concentration Over 24 Hour Study Period | 5.5 microM | Standard Error 0.7 |
Primary
Peak Red Blood Cell (RBC) Iron-nitrosyl Hemoglobin (NO-Hb) Concentrations Over 24 Hour Study Period
Post-doses refers to that subjects will receive a single dose of each study drug, oral 15Nitrogen(15N)-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Red Blood Cell (RBC) Iron-nitrosyl Hemoglobin (NO-Hb) Concentrations Over 24 Hour Study Period | NA microMolar | — |
| Oral 15N-labeled Sodium Nitrite | Peak Red Blood Cell (RBC) Iron-nitrosyl Hemoglobin (NO-Hb) Concentrations Over 24 Hour Study Period | 1.04 microMolar | Standard Error 0.22 |
Secondary
Peak 15Nitrogen Nitro-conjugated Linoleic Acid (cLA) Concentrations Over 24 Hour Study Period
Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at time 0 (trough), every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose
Population: maximal at 24 hours with nitrate treatment, not detectable with nitrite treatment
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak 15Nitrogen Nitro-conjugated Linoleic Acid (cLA) Concentrations Over 24 Hour Study Period | 0.14 nanoMolar |
| Oral 15N-labeled Sodium Nitrite | Peak 15Nitrogen Nitro-conjugated Linoleic Acid (cLA) Concentrations Over 24 Hour Study Period | NA nanoMolar |
Secondary
Peak Change in Diastolic Blood Pressure Over 24 Hour Study Period
Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 0.75 hours reported
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Change in Diastolic Blood Pressure Over 24 Hour Study Period | -6.3 mmHg | Standard Error 1.2 |
| Oral 15N-labeled Sodium Nitrite | Peak Change in Diastolic Blood Pressure Over 24 Hour Study Period | -8.1 mmHg | Standard Error 6.4 |
Secondary
Peak Change in Heart Rate Over 24 Hour Study Period
Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline), every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 1.5 hours for nitrate and 24 hours for nitrite
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Change in Heart Rate Over 24 Hour Study Period | -6 beats per minute | Standard Error 4.1 |
| Oral 15N-labeled Sodium Nitrite | Peak Change in Heart Rate Over 24 Hour Study Period | 9 beats per minute | Standard Error 4.4 |
Secondary
Peak Change in Mean Arterial Pressure Over 24 Hour Study Period
Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 0.75 hours reported
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Change in Mean Arterial Pressure Over 24 Hour Study Period | -2.9 mmHg | Standard Error 2.1 |
| Oral 15N-labeled Sodium Nitrite | Peak Change in Mean Arterial Pressure Over 24 Hour Study Period | -10.4 mmHg | Standard Error 3.8 |
Secondary
Peak Change in Systolic Blood Pressure Over 24 Hour Study Period
Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline) then every 15 minutes during the first 2 hours post-dose, then at 3, 6, and 24 hours post-dose, change at 1.5 hours reported
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Change in Systolic Blood Pressure Over 24 Hour Study Period | -0.8 mmHg | Standard Error 2.9 |
| Oral 15N-labeled Sodium Nitrite | Peak Change in Systolic Blood Pressure Over 24 Hour Study Period | -12.1 mmHg | Standard Error 10.5 |
Secondary
Peak Percentage Level of Methemoglobin Over 24 Hour Study Period
Post-doses refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period
Time frame: measured at 0 (baseline), 0.5, 1, 2, 3, 6 and 24 hours post-doses
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Peak Percentage Level of Methemoglobin Over 24 Hour Study Period | 1.24 percentage level | Standard Error 0.08 |
| Oral 15N-labeled Sodium Nitrite | Peak Percentage Level of Methemoglobin Over 24 Hour Study Period | 1.59 percentage level | Standard Error 0.09 |
Secondary
Percent Platelet Activation at 6 Hours
at timepoint with greatest change from 0 (trough); Post-dose refers to that subjects will receive a single dose of each study drug, oral 15N-labeled sodium nitrate and nitrite, in random order, separated by a 3-7 day washout period; percentage of platelets that express 2 specific markers identifying activated platelets (CD41 and CD62-P) were quantified using flow cytometry
Time frame: measured at 0 (baseline), 6 and 24 hours post-dose
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oral 15N-labeled Sodium Nitrate | Percent Platelet Activation at 6 Hours | 9.0 % of platelets that are activated | Standard Error 1.7 |
| Oral 15N-labeled Sodium Nitrite | Percent Platelet Activation at 6 Hours | 8.3 % of platelets that are activated | Standard Error 1.9 |