MalesNO3-PreDMNCT07131384
Interaction Between Inorganic Nitrate Supplementation and Metformin in Individuals With Prediabetes
A study testing Dietary Supplement: Inorganic Nitrate (Beetroot juice) in people with Males and Females, run by University of Virginia at 1 site in United States.
Trial summary
This study is examining whether short-term supplementation with inorganic nitrate, in the form of beetroot juice, can enhance blood vessel health, insulin sensitivity, and exercise capacity in individuals with prediabetes. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- What is being tested?
- Dietary Supplement: Inorganic Nitrate (Beetroot juice)
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 24 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2026to 30 Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Individuals who can communicate meaningfully with the investigator and can provide written consent.
- Confirmed prediabetic individuals (ages 18-60 years old) (2-hour glucose of 140-199 mg/dL following OGTT test or HbA1c between 5.7-6.4% tested on two occasions within 6 months).
- Taking metformin (stable dose for at least a week) or naïve to metformin
- Sedentary (<1 day/week of structured exercise)
- Be able to perform exercise on a cycle ergometer without assistance
- Stable medication regimen for the last 6 months
- If female, have a normal menstrual cycle
Who cannot join
- Estimated Glomerular filtration rate (GFR) ≤ 45
- Body mass index ≥ 40 Kg/m2
- HbA1c > 6.4%
- Smokers within the last 5 years
- Has experienced significant weight loss ~3 kg in the last three months or is taking any weight loss drugs
- Current medical condition that prohibits exercising at high intensities
Show all 14Show fewer
- Currently on hormone replacement of any kind
- History of myocardial infarction, cerebrovascular event, acute or unstable disease other than pre-diabetes or obesity
- Currently taking any of the following medications (calcium channel blockers, statins, ACE or renin inhibitors, angiotensin receptor blockers, organic nitrates (e.g., nitroglycerine) or recent regular use of inorganic nitrates, alpha- or beta-blockers, diuretics, proton pump inhibitors, PDE-5 inhibitors (e.g.,: Cialis, Viagra), or xanthine oxidase inhibitors (e.g.,: Allopurinol))
- Oral antibiotic use within the previous four weeks, including over-the-counter antibacterial mouthwash or a mouthwash containing chlorhexidine and unwilling to discontinue use
- Oral cancer/severe oral disease
- Uncontrolled hypertension (>140/90)
- Had hysterectomy or oophorectomy
- Fetuses, neonates, children, prisoners, cognitively impaired, non-English speaking participants
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Virginia
Charlottesville, Virginia, 22903
434-243-8677, eta8xd@uvahealth.org
About this study
Official title: The Interaction Between Inorganic Nitrate Supplementation and Metformin on Exercise Capacity, Vascular Function, and Insulin Sensitivity in Individuals With Pre-Diabetes
This study is examining whether short-term supplementation with inorganic nitrate, in the form of beetroot juice, can enhance blood vessel health, insulin sensitivity, and exercise capacity in individuals with prediabetes. We will be comparing the responses in individuals who are taking metformin to those who are naive to metformin. The results from this study may help identify non-pharmacological interventions in prediabetes.
Read the detailed description
One in 10 Americans have diabetes, with ~ 95% having type 2 diabetes (T2D). Another 1 in 3 have prediabetes, with 70% developing T2D during their lifetimes. Exercise is the standard of care for T2D. However, responses to exercise are blunted in T2D, in part due to the widespread use of metformin, which may inhibit mitochondrial function. Alternative therapies, such as inorganic nitrate supplementation, may provide benefits without attenuating exercise responses.
Purpose: To examine inorganic nitrate supplementation on exercise tolerance, vascular function, and insulin sensitivity in subjects with PD (an ideal time to prevent progression to T2D) who are either taking or naïve to metformin pharmacotherapy.
This study willl recruit twenty-four individuals with PD (12 on, 12 metformin naïve) will participate in a double-blind cross-over design after either oral nitrate or placebo supplementation, including: 1) tests of vascular function (pulse wave velocity, flow mediated dilation, microvascular function with post-occlusive reactive hyperemia, local thermal heating, and skin ACh iontophoresis); 2) exercise testing to determine VO2peak and lactate threshold; 3) an oral glucose tolerance test; and 4) an exercise time trial to exhaustion.
- Conditions
- Males, Females, Sedentary, Metformin, Prediabetes
- Being tested
- Dietary Supplement: Inorganic Nitrate (Beetroot juice), Dietary supplement: Placebo (Nitrate-depleted beetroot juice)
- Keywords
- Prediabetic Individuals, Exercise Capacity, Vascular health, Inorganic nitrate, Insulin Sensitivity
- Medical subject headings
- Sedentary Behavior, Prediabetic State, Insulin Resistance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dietary Supplement: Inorganic Nitrate (Beetroot juice)Dietary supplement
Participants will be supplemented with inorganic nitrate in the form of beetroot juice for 4 days (12.9 mmol of NO3/day), and their vascular health, insulin sensitivity, and exercise capacity will be measured post-supplementation. This is a randomized crossover design with 2 parallel groups (Group 1: Currently taking metformin, Group 2: Naive to metformin).
Dietary supplement: Placebo (Nitrate-depleted beetroot juice)Dietary supplement
Participants will be supplemented with nitrate-depleted beetroot juice for 4 days (<0.01 mmol NO3/day), and their vascular health, insulin sensitivity, and exercise capacity will be measured post-supplementation. This is a randomized crossover design with 2 parallel groups (Group 1: Currently taking metformin, Group 2: Naive to metformin).
| Study group | Role | What they receive |
|---|---|---|
| Active Comparator (Naive to metformin) | Experimental | Participants will supplement with nitrate-rich beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. Receives: Dietary Supplement: Dietary Supplement: Inorganic Nitrate (Beetroot juice) |
| Placebo Comparator (Naive to metformin) | Placebo comparator | Participants will supplement with nitrate-depleted beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. Receives: Dietary Supplement: Dietary supplement: Placebo (Nitrate-depleted beetroot juice) |
| Active Comparator (Taking metformin) | Experimental | Participants will supplement with nitrate-rich beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. Receives: Dietary Supplement: Dietary Supplement: Inorganic Nitrate (Beetroot juice) |
| Placebo Comparator (Taking metformin) | Placebo comparator | Participants will supplement with nitrate-depleted beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. Receives: Dietary Supplement: Dietary supplement: Placebo (Nitrate-depleted beetroot juice) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Vascular Endothelial Function (Pulse wave analysis and velocity [PWA/V])
PWA/V- These measures will be calculated using the SphygmoCor XCEL system (AtCor Medical). This system will provide arterial stiffness, central, and peripheral pressure waveforms.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Vascular Endothelial Function (Flow-Mediated Dilation [FMD])
FMD- Participants will be placed in a supine position with their left forearm slightly extended and supinated, and their legs straight. The arteries will be imaged using a high-resolution 7.5 MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 3 minutes post-occlusion. An EKG trigger will be used to capture images during the end-diastole of the cardiac cycle.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Skin microvascular function using post-occlusive reactive hyperemia (PORH)
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. PORH will also be measured during the FMD measurement. Baseline measures will be captured, and the cuff will be inflated for 5 minutes, with the post-occlusion reactive period being measured. The laser positioned above the forearm skin will measure skin blood flow at all these time points.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout)
Skin microvascular function: Change in Skin Microvascular Dilation in Response to Local Thermal Heating
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. For LTH, ~2 mL of diH2O will be placed on a small disc on the forearm. The solution will be slowly heated to 44 °C. This will allow us to measure the endothelial function of the microcirculation in the skin.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Skin microvascular function: Change in microvascular dilation in response to acetylcholine (ACh)
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. For skin ACh iontophoresis, ~2 ml of 2% ACh solution (0.1g of ACh in diH2O and filtered) and low current will be used to deliver small quantities of ACh to the skin. This will allow us to measure the endothelial function of the microcirculation in the skin.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout)
Oral Glucose Tolerance Test (OGTT)
Participants will consume a 75g glucose beverage and then undergo a test to measure insulin, glucose, and C-peptide. A qualified team member will insert a catheter into the antecubital vein for the collection of blood. Blood will be collected at 5 timepoints to estimate insulin sensitivity: before drinking the 75g sugar beverage (0 minutes), and every 30 minutes until the end of the test (120 minutes). Participants will rest in a supine position for the duration of the test.
Measured: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Plasma Nitrate/Nitrite
Plasma samples will be collected to assess changes in plasma nitrate and nitrite following either BRJ or placebo.
Measured: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Cardiorespiratory fitness
Peak aerobic capacity (VO2peak) will be assessed on a cycle ergometer. An IV will be placed and lactate measured during rest and after the completion of every 3-minute stage to determine VO2 at lactate threshold and VO2peak.
Measured: 4 days following either active NO3 or placebo without nitrate (following 7 day washout).
Exercise time trial to exhaustion (TTE)
Participants will complete a time-to-exhaustion (TTE) test on a cycle ergometer. Participants will begin cycling for 4 minutes at 20 Watts as a warm-up. They will then cycle at a work rate equivalent to 75% of the difference between lactate threshold and VO2peak achieved prior. The TTE test will be terminated when pedal cadence falls ≥ 10 rpm for ≥ 5 sec. When participants reach exhaustion, they will complete a 3-minute unloaded recovery period on the cycle ergometer.
Measured: 4 days following either active NO3 or placebo without nitrate (following 7 day washout).
Tissue oxygenation during exercise (near-infrared spectropscopy [NIRS]
Tissue oxygenation will be captured noninvasively using near-infrared spectrometry (NIRS, PortaMon, Artinis Medical Systems B.V., The Netherlands) positioned on the gastrocnemius (calf) or vastus lateralis (quad) muscle during the VO2peak/lactate test.
Measured: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Oral nitrate reducing capacity (ONRC)
To assess the oral microbiome's ability to reduce nitrate to nitrite, the participant will rinse their mouth with a solution of potassium nitrate and ultra-pure water for five minutes. The rinsed solution will be collected into a 50ml Falcon tube. The nitrite concentration will be measured to determine ONRC
Measured: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Secondary outcomes (3)
Oral Microbiome
In order to assess abundance and classification of nitrate-reducing bacteria, a sample of the oral microbiome will be obtained. The dorsal surface of the tongue will be swabbed using a 6" HydraFlock Sterile Large Flock Swab for 60 seconds (Puritan Medical Products, USA). Additionally, an unstimulated saliva sample (~5ml) will be collected through an unstimulated drool technique. Both swab and saliva samples will be sequenced to analyze bacteria present in the oral microbiome following supplement/placebo.
Measured: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Biomarker Analyses: Concentration of Inflammatory markers in fasting blood plasma
The investigators plan to assess various markers of inflammation. A fasting blood sample will be collected to measure markers of inflammation.
Measured: Sample collected 4 days post active NO3 juice/placebo and will be analyzed post study completion.
Biomarker Analyses: Concentration of Oxidative stress markers in fasting blood plasma
The investigators plan to assess various markers of oxidative stress. A fasting blood sample will be collected to measure markers of oxidative stress.
Measured: Sample collected 4 days post active NO3 juice/placebo and will be analyzed post study completion.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Aug 2025
- Study start1 Jan 2026
- Primary completion1 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MalesStudies of the same condition, open and under way.
- More trials run by University of VirginiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Virginia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jason Allen, University of Virginia
- Investigators
- Jason Allen, PhD, Principal investigator, University of Virginia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07131384
- Sponsor's protocol ID
- 302659
- Acronym
- NO3-PreDM
- Status last verified
- Jun 2026
- First submitted
- 6 Aug 2025
- Last updated
- 3 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Interaction Between Inorganic Nitrate Supplementation and Metformin on Exercise Capacity, Vascular Function, and Insulin Sensitivity in Individuals With Pre-Diabetes
- ClinicalTrials.gov ID
- NCT07131384
- Acronym / sponsor ID
- NO3-PreDM / 302659
- Conditions
- Males, Females, Sedentary, Metformin, Prediabetes
- Keywords
- Prediabetic Individuals, Exercise Capacity, Vascular health, Inorganic nitrate, Insulin Sensitivity
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- University of VirginiaUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 1 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 20 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is examining whether short-term supplementation with inorganic nitrate, in the form of beetroot juice, can enhance blood vessel health, insulin sensitivity, and exercise capacity in individuals with prediabetes. We will be comparing the responses in individuals who are taking metformin to those who are naive to metformin. The results from this study may help identify non-pharmacological interventions in prediabetes.
Detailed description
One in 10 Americans have diabetes, with ~ 95% having type 2 diabetes (T2D). Another 1 in 3 have prediabetes, with 70% developing T2D during their lifetimes. Exercise is the standard of care for T2D. However, responses to exercise are blunted in T2D, in part due to the widespread use of metformin, which may inhibit mitochondrial function. Alternative therapies, such as inorganic nitrate supplementation, may provide benefits without attenuating exercise responses.
Purpose: To examine inorganic nitrate supplementation on exercise tolerance, vascular function, and insulin sensitivity in subjects with PD (an ideal time to prevent progression to T2D) who are either taking or naïve to metformin pharmacotherapy.
This study willl recruit twenty-four individuals with PD (12 on, 12 metformin naïve) will participate in a double-blind cross-over design after either oral nitrate or placebo supplementation, including: 1) tests of vascular function (pulse wave velocity, flow mediated dilation, microvascular function with post-occlusive reactive hyperemia, local thermal heating, and skin ACh iontophoresis); 2) exercise testing to determine VO2peak and lactate threshold; 3) an oral glucose tolerance test; and 4) an exercise time trial to exhaustion.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Active Comparator (Naive to metformin) | Experimental | Dietary Supplement: Dietary Supplement: Inorganic Nitrate (Beetroot juice)Participants will supplement with nitrate-rich beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. |
| Placebo Comparator (Naive to metformin) | Placebo comparator | Dietary Supplement: Dietary supplement: Placebo (Nitrate-depleted beetroot juice)Participants will supplement with nitrate-depleted beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. |
| Active Comparator (Taking metformin) | Experimental | Dietary Supplement: Dietary Supplement: Inorganic Nitrate (Beetroot juice)Participants will supplement with nitrate-rich beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. |
| Placebo Comparator (Taking metformin) | Placebo comparator | Dietary Supplement: Dietary supplement: Placebo (Nitrate-depleted beetroot juice)Participants will supplement with nitrate-depleted beetroot juice (BRJ) for 4 days: 6.45 mmol of NO3 in the morning and 6.45 mmol in the evening for 3 days, and 12.9 mmol 2 hours before the lab visit. Supplement order based on randomization and crossover will happen after a minimum of a 7-day washout period. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Individuals who can communicate meaningfully with the investigator and can provide written consent.
- Confirmed prediabetic individuals (ages 18-60 years old) (2-hour glucose of 140-199 mg/dL following OGTT test or HbA1c between 5.7-6.4% tested on two occasions within 6 months).
- Taking metformin (stable dose for at least a week) or naïve to metformin
- Sedentary (<1 day/week of structured exercise)
- Be able to perform exercise on a cycle ergometer without assistance
Key exclusion criteria (14 listed)
- Estimated Glomerular filtration rate (GFR) ≤ 45
- Body mass index ≥ 40 Kg/m2
- HbA1c > 6.4%
- Smokers within the last 5 years
- Has experienced significant weight loss ~3 kg in the last three months or is taking any weight loss drugs
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dietary Supplement: Inorganic Nitrate (Beetroot juice)Participants will be supplemented with inorganic nitrate in the form of beetroot juice for 4 days (12.9 mmol of NO3/day), and their vascular health, insulin sensitivity, and exercise capacity will be measured post-supplementation. This is a randomized crossover design with 2 parallel groups (Group 1: Currently taking metformin, Group 2: Naive to metformin). | Dietary supplement | Active Comparator (Naive to metformin), Active Comparator (Taking metformin) |
| Dietary supplement: Placebo (Nitrate-depleted beetroot juice)Participants will be supplemented with nitrate-depleted beetroot juice for 4 days (<0.01 mmol NO3/day), and their vascular health, insulin sensitivity, and exercise capacity will be measured post-supplementation. This is a randomized crossover design with 2 parallel groups (Group 1: Currently taking metformin, Group 2: Naive to metformin). | Dietary supplement | Placebo Comparator (Naive to metformin), Placebo Comparator (Taking metformin) |
Primary outcome
Vascular Endothelial Function (Pulse wave analysis and velocity [PWA/V])
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
PWA/V- These measures will be calculated using the SphygmoCor XCEL system (AtCor Medical). This system will provide arterial stiffness, central, and peripheral pressure waveforms.
Vascular Endothelial Function (Flow-Mediated Dilation [FMD])
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
FMD- Participants will be placed in a supine position with their left forearm slightly extended and supinated, and their legs straight. The arteries will be imaged using a high-resolution 7.5 MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 3 minutes post-occlusion. An EKG trigger will be used to capture images during the end-diastole of the cardiac cycle.
Skin microvascular function using post-occlusive reactive hyperemia (PORH)
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout)
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. PORH will also be measured during the FMD measurement. Baseline measures will be captured, and the cuff will be inflated for 5 minutes, with the post-occlusion reactive period being measured. The laser positioned above the forearm skin will measure skin blood flow at all these time points.
Skin microvascular function: Change in Skin Microvascular Dilation in Response to Local Thermal Heating
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. For LTH, ~2 mL of diH2O will be placed on a small disc on the forearm. The solution will be slowly heated to 44 °C. This will allow us to measure the endothelial function of the microcirculation in the skin.
Skin microvascular function: Change in microvascular dilation in response to acetylcholine (ACh)
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout)
Skin microvascular function will be measured using Moor Instruments' FLPI-2 laser speckle imaging system. For skin ACh iontophoresis, ~2 ml of 2% ACh solution (0.1g of ACh in diH2O and filtered) and low current will be used to deliver small quantities of ACh to the skin. This will allow us to measure the endothelial function of the microcirculation in the skin.
Oral Glucose Tolerance Test (OGTT)
Time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).
Participants will consume a 75g glucose beverage and then undergo a test to measure insulin, glucose, and C-peptide. A qualified team member will insert a catheter into the antecubital vein for the collection of blood. Blood will be collected at 5 timepoints to estimate insulin sensitivity: before drinking the 75g sugar beverage (0 minutes), and every 30 minutes until the end of the test (120 minutes). Participants will rest in a supine position for the duration of the test.
Plasma Nitrate/Nitrite
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Plasma samples will be collected to assess changes in plasma nitrate and nitrite following either BRJ or placebo.
Cardiorespiratory fitness
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7 day washout).
Peak aerobic capacity (VO2peak) will be assessed on a cycle ergometer. An IV will be placed and lactate measured during rest and after the completion of every 3-minute stage to determine VO2 at lactate threshold and VO2peak.
Exercise time trial to exhaustion (TTE)
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7 day washout).
Participants will complete a time-to-exhaustion (TTE) test on a cycle ergometer. Participants will begin cycling for 4 minutes at 20 Watts as a warm-up. They will then cycle at a work rate equivalent to 75% of the difference between lactate threshold and VO2peak achieved prior. The TTE test will be terminated when pedal cadence falls ≥ 10 rpm for ≥ 5 sec. When participants reach exhaustion, they will complete a 3-minute unloaded recovery period on the cycle ergometer.
Tissue oxygenation during exercise (near-infrared spectropscopy [NIRS]
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Tissue oxygenation will be captured noninvasively using near-infrared spectrometry (NIRS, PortaMon, Artinis Medical Systems B.V., The Netherlands) positioned on the gastrocnemius (calf) or vastus lateralis (quad) muscle during the VO2peak/lactate test.
Oral nitrate reducing capacity (ONRC)
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
To assess the oral microbiome's ability to reduce nitrate to nitrite, the participant will rinse their mouth with a solution of potassium nitrate and ultra-pure water for five minutes. The rinsed solution will be collected into a 50ml Falcon tube. The nitrite concentration will be measured to determine ONRC
3 secondary outcomes
Oral Microbiome
Time frame: 4 days following either active NO3 or placebo without nitrate (following 7-day washout).
Biomarker Analyses: Concentration of Inflammatory markers in fasting blood plasma
Time frame: Sample collected 4 days post active NO3 juice/placebo and will be analyzed post study completion.
Biomarker Analyses: Concentration of Oxidative stress markers in fasting blood plasma
Time frame: Sample collected 4 days post active NO3 juice/placebo and will be analyzed post study completion.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jason Allen, PhD principal investigator
University of Virginia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dietary Supplement: Inorganic Nitrate (Beetroot juice) in people with Males and Females, run by University of Virginia at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Money Ghimire, M.S (4342438677, eta8xd@uvahealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Vascular Endothelial Function (Pulse wave analysis and velocity [PWA/V]) (time frame: 3 days following either active NO3 or placebo without nitrate (following 7-day washout).). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jun 2026.