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Active, Not Recruiting

NCT Number: NCT03826147

Nitrite-boosting Therapy for Improving Physiological Function in Patients With Chronic Kidney Disease

Nitric oxide (NO) is an essential molecule in the body that is decreased in patients with chronic kidney disease (CKD), leading to reductions in vascular, movement ("motor") and cognitive functions. This study will determine if daily oral supplementation (3 months) with a supplement that increases NO in the body, i.e., nitrate-rich beetroot juice, improves vascular, motor and cognitive function in patients with CKD; this study will also provide insight into the biological reasons (mechanisms) by which supplementation with nitrate-rich beetroot juice improves vascular function in these patients. Overall, this research will provide scientific evidence supporting the use of nitrate-rich beetroot juice for preserving physiological function and preventing co-morbid clinical conditions and disability in CKD.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Chronic Kidney Disease Chronic Disease Disease Attributes Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Diseases Male Urogenital Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Renal Insufficiency Renal Insufficiency, Chronic Urogenital Diseases Urologic Diseases

Age range

30 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Integrative Physiology of Aging Laboratory

Boulder, Colorado, 80309, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • CKD stage II-IV (eGFR using the Modification of Diet in Renal Disease (MDRD) prediction equation 20-90 mL/min/1.73m2; stable renal function in the past 3 months)
  • Ability to give informed consent
  • Albumin > 3.0 g/dL
  • Ability to perform motor and cognitive tests (e.g., can rise from a chair, walk for 6 min, climb 10 stairs)
  • Free from alcohol dependence or abuse, as defined by the American Psychiatry Association, Diagnostic and Statistical Manual of Mental Disorders (DSM-V)
  • Mini-mental state examination score >21 (rationale: to screen for subjects with major cognitive impairment)
  • Blood pressure (BP) >100/60 mmHg for past 3 months (rationale: blood pressure below 100/60 mmHg may elevate the normally small risk of hypotension with nitrate supplementation)
  • Not taking medications that will interfere with administered medications (e.g., sildenafil interacts with nitroglycerin)
  • Body mass index (BMI) <40 kg/m2 (vascular function measurements can be inaccurate in severely obese patients)

Exclusion criteria

  • Life expectancy <1 year
  • Uncontrolled hypertension, defined as blood pressure > 160/100 mmHg in the past 3 months
  • History of severe liver disease
  • History of severe congestive heart failure (i.e., ejection fraction < 35%)
  • History of hospitalizations within the last 3 months
  • Active infection or antibiotic therapy
  • Warfarin use
  • Vasculitis requiring immunosuppressive therapy within the last year
  • High dietary nitrate intake or current nitrate/nitrite supplementation; hypersensitivity to nitrates or nitrites
  • Glucose-6-phosphate dehydrogenase deficiency or blood methemoglobin >2%
  • Unwilling to abstain from use of mouthwash or other oral hygiene practices (e.g., tongue scraping) outside of teeth brushing that disrupt the oral microbiome and would interfere with nitrate conversion to nitrite
  • Blood donation within 8 weeks prior to enrolling in the study; unwilling to abstain from donating blood for 8 weeks after completing the study

Treatment and study plan

Nitrate-rich beetroot Juice

Dietary Supplement

Daily supplementation with ~100 kcal of nitrate-rich beetroot juice containing 400 mg of dietary nitrate (James White Drinks, UK).

Nitrate-depleted beetroot juice

Dietary Supplement

Daily supplementation with ~100 kcal of nitrate-depleted beetroot juice (James White Drinks, UK).

Primary outcomes

  1. Change in vascular endothelial function

    Time frame: Baseline, 3 months

    as measured by brachial artery flow-mediated dilation

  2. Change in aortic stiffness

    Time frame: Baseline, 3 months

    as measured by carotid-femoral pulse wave velocity

Secondary outcomes

  1. Change in oxidative stress-associated suppression of endothelial function assessed as the increase in brachial artery flow-mediated dilation following an ascorbic acid infusion

    Time frame: Baseline, 3 months

    The influence of oxidative stress on brachial artery flow-mediated dilation will be determined by infusing a supraphysiological dose of ascorbic acid known to scavenge superoxide or isovolumic saline

  2. Change in endothelial cell markers of oxidative stress

    Time frame: Baseline, 3 months

    Endothelial cell nitrotyrosine levels will be determined

Other outcomes

  1. Motor function composite score

    Time frame: Baseline, 3 months

    Multiple domains of motor function (including endurance, strength, dexterity) assessed using the NIH Toolbox Motor Battery (aggregated into one reported value)

  2. Fluid cognition composite score

    Time frame: Baseline, 3 months

    Multiple domains of cognitive function (including executive function, memory, processing speed) assessed using the NIH Toolbox Cognitive Battery (aggregated into one reported value)

Sponsors and collaborators

Lead sponsor

University of Colorado, Boulder

Other

Registry information

Important dates

Study start
2019
Primary completion
2026
Study completion
2026
First posted
Feb 1, 2019
Registry last updated
Mar 31, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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