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

Effects of L-Citrulline Supplementation on Vascular Function During Fasted and Acute Hyperglycemia in Middle-aged and Older Women With Metabolic Syndrome

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06025357
Enrollment
24
Registered
2023-09-06
Start date
2023-01-01
Completion date
2024-08-01
Last updated
2025-05-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Menopause, Metabolic Syndrome

Keywords

Endothelial function, Aortic Hemodynamics, Blood pressure, Obesity, Hypertension

Brief summary

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.

Detailed description

Using a double-blind, randomized, placebo-controlled, and parallel design, middle-aged and older women with metabolic syndrome will be randomized into receiving either CIT supplementation (10g/day) or placebo (Microcrystalline Cellulose) for 4 weeks. The first visit will be approximately 1hr and 30 minutes. The 2nd and 3rd visits will each be approximately 2hrs and 30 minutes, separated by 4 weeks in between each visit. During visits 2 and 3, vascular measurements will be assessed in the fasted state and 30, 60, and 90 minutes after acute glucose ingestion (75g).

Interventions

4 weeks of L-Citrulline supplementation (10 grams/day).

DIETARY_SUPPLEMENTPlacebo

4 weeks of microcrystalline Cellulose supplementation.

Sponsors

Texas Tech University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)

Intervention model description

Parallel Assignment Double (Participant, Investigator) Randomized, double-blind, placebo-controlled, parallel study design

Eligibility

Sex/Gender
FEMALE
Age
45 Years to 79 Years
Healthy volunteers
Yes

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 The following are also inclusion criteria's: * Women aged 45-79 years old * Body mass index ≤ 39.9 kg/m2 * Sedentary (defined as \< 120 min/week of exercise) * Abstain from any dietary supplements with vascular effects for one month prior to the beginning of the study and until participation in study has terminated.

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

Design outcomes

Primary

MeasureTime frameDescription
24-hour ambulatory blood pressure monitoring4 weeksAn ambulatory blood pressure cuff, measuring blood pressure for 24-hours will be obtained on two separate days at baseline and after 4 weeks of supplementation.
Blood pressure during acute hyperglycemia4 weeksBrachial and aortic blood pressures (systolic and diastolic) will be assessed using an automated sphygmomanometry arm cuff (SphygmoCor XCEL). Beat-to-beat blood pressure will be measured using an automated photoplethysmography finger cuff (Fineometer). Blood pressure will be measured after an oral glucose ingestion at 30, 60, and 90 minutes at baseline and after 4 weeks of supplementation.
Total peripheral resistance in the fasted condition.4 weeksTotal peripheral resistance will be measured using an automated photoplethysmography finger cuff (Finometer) at baseline and after 4 weeks of supplementation.
Total peripheral resistance during acute hyperglycemia4 weeksTotal peripheral resistance will be measured using an automated photoplethysmography finger cuff (Finometer) at 30, 60, and 90 minutes after oral glucose ingestion at baseline and after 4 weeks of supplementation.
Stroke volume in the fasted condition4 weeksStroke volume will be measured using an automated photoplethysmography finger cuff (Finometer) at baseline and after 4 weeks of supplementation.
Stroke volume during acute hyperglycemia4 weeksStroke volume will be measured using an automated photoplethysmography finger cuff (Finometer) at 30, 60, and 90 minutes after oral glucose ingestion at baseline and after 4 weeks of supplementation.
Macrovascular Endothelial function in the fasted condition4 weeksEndothelial 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 condition4 weeksEndothelial 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 condition4 weeksEndothelial 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 hyperglycemia4 weeksEndothelial 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 hyperglycemia4 weeksEndothelial 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.
Central and peripheral arterial stiffness in the fasted condition4 weeksArterial stiffness will be measured using central (carotid-femoral) and peripheral (femoral-ankle) PWV at baseline and after 4 weeks of supplementation.
Central arterial stiffness during acute hyperglycemia4 weeksArterial stiffness will be measured using central (carotid-femoral) PWV at 30, 60, and 90 minutes after oral glucose ingestion at baseline and after 4 weeks of supplementation.
Blood pressure in the fasted condition4 weeksBrachial and aortic blood pressures will be assessed using an automated sphygmomanometry arm cuff (SphygmoCor XCEL). Beat-to-beat blood pressure will be measured using an automated photoplethysmography finger cuff (Fineometer). Blood pressure will be measured at baseline and after 4 weeks of supplementation.

Secondary

MeasureTime frameDescription
Serum glucose and insulin levels.4 weeksSerum glucose and insulin levels will be tested at baseline and after 4 weeks of supplementation.
Serum arginine levels4 weeksSerum L-Arginine levels will be tested at baseline and after 4 weeks of supplementation.
Serum Nitric Oxide levels4 weeksSerum nitric oxide levels will be tested at baseline and after 4 weeks of supplementation.
Serum Endothelin-1 levels4 weeksSerum endothelin-1 levels will be tested at baseline and after 4 weeks of supplementation.
Serum arginase levels4 weeksSerum arginase levels will be tested at baseline and after 4 weeks of supplementation.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026