Effects of L-citrulline Supplementation on Vascular Function in Metabolic Syndrome

What this trial studies

The objective of this project is to provide evidence that L-Citrulline (CIT) supplementation can improve vascular function in the fasted and acute hyperglycemia conditions in middle-aged and older women with metabolic syndrome.

Conditions in scope

• Metabolic Syndrome
• Menopause

Interventions

• L-Citrulline supplementation (Dietary Supplement) — 4 weeks of L-Citrulline supplementation (10 grams/day).
• Placebo (Dietary Supplement) — 4 weeks of microcrystalline Cellulose supplementation.

Who can join

Women only · Ages 45 Years to 79 Years · Accepts healthy volunteers.

Inclusion criteria

• Must present at least 3 of the following 5 cardiometabolic risk factors
• Waist circumference ≥88 cm
• Fasting glucose between 100-125 mg/dL or HbA1c between 5.7-6.4%.
• Blood pressure ≥130 mm Hg
• Triglyceride ≥ 150 mg/dL
• HDL \<50 mg/dL
• Women aged 45-79 years old
• Body mass index ≤ 39.9 kg/m2

Exclusion criteria

• \< 45 and \> 79 years of age
• Use of medications and/or any supplements that may affect outcome variables (such as arginine-containing supplements, nitroglycerin, statin drugs, biguanides, insulin, beta blockers, statins, verapamil)
• Systolic blood pressure ≥ 160 mmHg
• BMI \> 40 kg/m2
• Recent changes in medication (3 months)
• Current smoking any tobacco use
• Cardiovascular disease, diabetes (Type 1 or 2), and other metabolic or chronic diseases
• More than 7 alcoholic drinks/week of consumption

Eligibility wording paraphrased from the public record. View the full criteria on ClinicalTrials.gov before contacting a site.

Where it’s happening

Status & timeline

• Overall status: Completed
• Study type: Interventional
• Phase: N/A
• Start date: 2023-01-01
• Primary completion: 2024-05-01
• Last update posted: 2025-05-15
• First posted: 2023-09-06

Sponsor & contact

Lead sponsor: Texas Tech University (Other)

For trial site contact information, use the official record at ClinicalTrials.gov. Contact details change frequently and the public record is the source of truth.

Outcome measures

Primary outcomes

• Macrovascular Endothelial function in the fasted condition (4 weeks)
  Endothelial function will be measured via brachial artery flow mediated dilation (ultrasonography) during reactive hyperemia at baseline and after 4 weeks of supplementation.
• Microvascular endothelial function in the fasted condition (4 weeks)
  Endothelial function will be measured using forearm muscle oxygenation (near-infrared spectroscopy) will assessed during reactive hyperemia at baseline and after 4 weeks of supplementation.
• Microvascular digital endothelial function in the fasted condition (4 weeks)
  Endothelial function will be measured using peripheral (finger) arterial tonometry (EndoPAT device) during reactive hyperemia at baseline and after 4 weeks of supplementation.
• Macrovascular Endothelial function during acute hyperglycemia (4 weeks)
  Endothelial function will be measured via brachial artery flow mediated dilation (ultrasonography) during reactive hyperemia at 30, 60, and 90 minutes after oral glucose ingestion at baseline and after 4 weeks of supplementation.
• Microvascular forearm endothelial function during acute hyperglycemia (4 weeks)
  Endothelial function will be measured using forearm muscle oxygenation (near-infrared spectroscopy) during reactive hyperemia at 30, 60, and 90 minutes after oral glucose ingestion at baseline and after 4 weeks of supplementation.

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